General Maintenance & Repairs - Car idleing low! (Gas milage cut in half!)

It's been cold but not that bad, I'm in Washington. I noticed my gas mileage had been seeming like I wasn't getting but 10mpg or so, so last night I got a full tank to check here and see for sure. My change oil light just came on and I don't think it's time for a change yet but I should check when I did last and the oil level. Anyways, this morning I turn the key and usually there is a gush of power like any other cold start, but this time it barely got going and sounded really weak, I gave it a little gas (only a small throttle blip) an it went to 1200 like normal but then falls very low to around 500 and sounded like it was going to die. Then it gets it's self back up to a somewhat normal running rpm around a thousand. I did this a couple times, same thing. I had to go though so I had to get a ride and check things later. Anyone know what this could be? Plugs? Maf? Fuel line? I haven't seen any leaks I did check that..

Oh and also this car has been very reliable and strong so far. No new mods put on. And nothing is different with the car or driving as far as I can remember

Maf, IAC, or possible vaccuum leak.

I was thinking about taking it to autozone and getting a scan, but I haven't messed around enough to see if it will even get out of the driveway. What should I start checking?

Is is throwing an ses light?

Try cleaning the maf, and see if you can find any vaccuum leaks.

It used to throw an egr or air code for a while I think due to unplugged o2s but it ran fine. Now there's no more ses light.. How do i check for vacuum leaks?

And I was reading on cleaning the Maf last night ironically enough. Do I get that spray stuff and just shoot it into it?

It's not the "safe" way to do it, but I would spray a little bit of starter fluid under the hood while it was running and see if the car idles up. Again, most people don't recommend doing it like this.

Ok like into the Maf?

Ok like into the Maf?

No, just around the engine bay if you are trying to find a vaccuum leak. Again, this is just how I've done it.

As far as cleaning your maf, I know that's a delicate process because you can end up screwing it up if you aren't careful. I don't run one, but I'm sure someone can chime in to walk you thru it.

Ok! Yeah I just need to be pointed in the right direction I can search for all that too. Haven't encountered this before so it's a new experience. Should come out learning more though! :D hopefully it's not too extensive..

Well i got the idle working good again and it seems to be doing just fine, just some cleaning and letting it run/opening it up. Must have gotten gummed up. But now i have found out for sure that my milage is cut in half! It normaly gets upper 20's close to 30 when i drive and its getting exactly half, 15mpg. I did a milage/fule use check so im not going by the gauge, what would make me get such shitty gas milage all of a suddon?

You still have the O2's unplugged without tuning them out?

vac leak would probably idle too high not low
maf seems doubtful
IAC seems likely

Well i just scanned it and the only code showing up as the P0410 which is the senconday air injections system which can be:

Circuit relay defective or fuse open
Check connector and wiring
Air pump defective or hoses blocked.

However, this could not be the reason for going from 30 to 15mpg. If i am not mistaken all the secondary air system does is put more air out to get the exhaust hotter and get the cats 'primed'. Anyone know what could cause my gas to be going?? I checked for leaks on the ground and there are none. Doesnt look like anything is unplugged in the engine bay.. Thanks for all the help so far guys!

You could have a leaky fuel injector, that will kill your gas mileage and cause rough idling and hard starts. No codes for this either...........

I'd check my battery too, that can cause idle issues especially at cold start up. It could have short.

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If there was a leak with a fule injector i would be able to notice by looking in under the hood while its running right? I havent really seen anything obvious..

If there was a leak with a fule injector i would be able to notice by looking in under the hood while its running right? I havent really seen anything obvious..

No. You must lift all fuel injectors out of the intake, leaving them all plugged in electrically and connected to the fuel rail. Then turn the key to "On" so the fuel pump primes and see if any of them leak.

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Ok ill try that.

I was messing around with the car this weekend and i cant figure out how to get all the injectors out while still leaving them plugged in and connected to the fuel rail. Can anyone tell me how to go about doing this or direct me somewhere. I was also thinking about taking it into an auto shop and just gettting a compression test and leak down as well. Would like to fix it myself if i can however

I was messing around with the car this weekend and i cant figure out how to get all the injectors out while still leaving them plugged in and connected to the fuel rail. Can anyone tell me how to go about doing this or direct me somewhere. I was also thinking about taking it into an auto shop and just gettting a compression test and leak down as well. Would like to fix it myself if i can however

I've never had to do it myself, this is how people have described doing it though. I would unplug each injector, remove the rails, then remove the injectors from the intake. Then reconnect them to the rails and see if they leak that way.


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Ok yeah i was thinking you would have to just do it that way.. On a cold start i noticed a very slight ticking sound when i accelerated, sounded more like an electronic clicking then say a spun bearing or piston slap, didnt seem loud or metal sounding enough.. does that mean anything? Its not very noticable at all and the other day i cold started it again and didnt hear anything

Ok yeah i was thinking you would have to just do it that way.. On a cold start i noticed a very slight ticking sound when i accelerated, sounded more like an electronic clicking then say a spun bearing or piston slap, didnt seem loud or metal sounding enough.. does that mean anything? Its not very noticable at all and the other day i cold started it again and didnt hear anything

Man, I don't know. Sometimes I've heard wierd ticking noises throughout the years and then its not there one day.....
If you suspect the injectors I think you can touch them with a screwdriver while the engine is idling to feel the ticking of each one. See if one might be missing a little bit.

But some guy told me that if one injector on a side is "electrically" having trouble it will take out all 4 on that side. Not leaks or dirt in them, but an electronic issue. Not sure if thats true or not though....

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Oh wow, yeah i still think i have most all my power still there, i took it out the other day and opened it up to see if it would clean out a little and it didnt but it felt like all the power was there. Im thinking ill just take it in today to a shop, i should probably get a compression test and leak down done anyways before i put the car on nitrous

Oh wow, yeah i still think i have most all my power still there, i took it out the other day and opened it up to see if it would clean out a little and it didnt but it felt like all the power was there. Im thinking ill just take it in today to a shop, i should probably get a compression test and leak down done anyways before i put the car on nitrous

Yea, definitely do those tests before the nitrous. Bent valves/pushrods can also cause power issues and missing. I think the leakdown test will find that. Not sure......

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Yeah ill be taking it in today most likely ill post results

Just got quoted around town for ~350 on the low side for a compression test and leak down. The compression test is logged in their books for 3 hours im guessing because of the rear plug.. would it be cheaper to rent one or something? 350 is alot for just that imo..

Maf...

Unplugged? I checked already..

Unplugged? I checked already..

Have you tried cleaning it yet?

Just got quoted around town for ~350 on the low side for a compression test and leak down. The compression test is logged in their books for 3 hours im guessing because of the rear plug.. would it be cheaper to rent one or something? 350 is alot for just that imo..

Thats ridiculous. Maybe someone from an F-Body club near you if you have one. I found a guy in a club that did it for me for free if I helped him. Maybe you can ask around....or on the local forums.

Call around to more shops. Shops will do a leakdown check around here for $100. Make sure you put in new spark plugs when you do it......lol

You could buy a leakdown kit...its extremely easy to do yourself.

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Unplugged? I checked already..

Its not the MAF.....MAF doesn't come into play until you go WOT....and its used for cold starts until you reach 122*F. I think its 122*F....either way its only used for cold starts and WOT.

Its not that.......

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I havent cleaned it yet, i was going to put in some injector cleaner fluid today, clean the maf and do some of that seafoam stuff. Then i figure if that doesnt clear it up, and ill want to be changing the plugs here anyways to borrow or buy a $20 compression checker and do that when im changing the plugs. Then if that doesnt do anything ill probably just take it in to get a leak down or figure out what exactly to do with checking out my injectors and all. Sound like a good plan? Also i dont know to run the tr55 or tr6 plugs.. I wanted to run the tr6 but the nitrous may be a while yet..

I havent cleaned it yet, i was going to put in some injector cleaner fluid today, clean the maf and do some of that seafoam stuff. Then i figure if that doesnt clear it up, and ill want to be changing the plugs here anyways to borrow or buy a $20 compression checker and do that when im changing the plugs. Then if that doesnt do anything ill probably just take it in to get a leak down or figure out what exactly to do with checking out my injectors and all. Sound like a good plan? Also i dont know to run the tr55 or tr6 plugs.. I wanted to run the tr6 but the nitrous may be a while yet..

Are you near any Texas speed shops by chance? Go ahead and do those things to see if it clears the problem, if its still there you may need someone that knows their shit to check for bent valves or pushrods.

As for the spark plugs....NGK TR55 or TR5 is what you want. They are 100% identical plugs, they just come gapped differently from the factory.
BUT.......you need to get a gapper tool and gap them all to .050 Thats the best gap for LS1 Normally Aspirated engine from bone stock to 650 RWHP.

I was going to put a TNT wet shot on mine years ago and put TR6 plugs in gapped to .035, before my nitrous was installed. I decided then not to do nitrous back then. I have no idea why, but it ran like shit with the TR6's. I took them out, put the TR55's back in gapped to .050 and my engine ran perfect again. So I don't know what was up there.

I would just use TR55 .050 for now. When you get the nitrous, change to a colder plug.

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Ok, yeah i was thinking just the tr55 for now..i didnt know you had to gap them though? I just picked up some supertech fuel injector cleaner, prob skip on the seafoam, and ill clean my maf today see if that helps at all..

Ok, yeah i was thinking just the tr55 for now..i didnt know you had to gap them though? I just picked up some supertech fuel injector cleaner, prob skip on the seafoam, and ill clean my maf today see if that helps at all..

Always at least check the gaps for accuracy. If a box gets dropped in shipping or banged or people have taken them out of the box to loo kat them and drop them.......you might put a few in that just aren't right. Get the tool and check them. It takes 5 seconds per plug to check.

Also, put dielectric grease all over both the plug tip and ceramic. Also, put a blob inside the spark plug wire end and up into the coil port. As well as anti-sieze on the threads.

THEN......only put them in hand tight with a socket. Hold the socket by hand and tighten it as much as possible. Then with the ratchet, literally just snug them on. You'll have a very easy time getting them out next time.

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Awesome thanks for the info ill do that when i get them. Where does everyone get there plugs from usually? Just anywhere?

Awesome thanks for the info ill do that when i get them. Where does everyone get there plugs from usually? Just anywhere?

Around here, every Advance Auto has them, and there's 5 of them within 7 miles of my house. I would think most parts places do.

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Well yesterday I got my plugs swapped with the tr55's and the previous owner has changed the easiest first 3 plugs on the drivers side with Bosch plugs and left the rest :lol: anywas got em switched and they looked pretty done, I did a compression test and found all the cylinders to be around 165 + - 5 lbs/square inch so I didn't even bother doing a wet test, car ran better after I did that I also fixed the secondary air code because when I took it of it was clogged with the old gasket that must have broke. The problem is still there though.. How could I be looking this much gas??

Sorry I'm on my damn phone so it's slaughtered what i tried to say, plus im a couple in now

its not the maf.....maf doesn't come into play until you go wot....and its used for cold starts until you reach 122*f. I think its 122*f....either way its only used for cold starts and wot.

Its not that.......

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ok...

it's been cold but not that bad, i'm in washington. I noticed my gas mileage had been seeming like i wasn't getting but 10mpg or so, so last night i got a full tank to check here and see for sure. My change oil light just came on and i don't think it's time for a change yet but i should check when i did last and the oil level. anyways, this morning i turn the key and usually there is a gush of power like any other cold start, but this time it barely got going and sounded really weak, i gave it a little gas (only a small throttle blip) an it went to 1200 like normal but then falls very low to around 500 and sounded like it was going to die. Then it gets it's self back up to a somewhat normal running rpm around a thousand. I did this a couple times, same thing. I had to go though so i had to get a ride and check things later. Anyone know what this could be? Plugs? Maf? Fuel line? I haven't seen any leaks i did check that..

I think with yhe cold start I just had something gummed up.its been doing fine starting up now and yhe clicking I belive is the gasket missing from yhe secondary air. My only problem is yhe bad gas milage now.. Still havent gone through all that injector cleaner yet but.it doesnt seem to be helping much

I think with yhe cold start I just had something gummed up.its been doing fine starting up now and yhe clicking I belive is the gasket missing from yhe secondary air. My only problem is yhe bad gas milage now.. Still havent gone through all that injector cleaner yet but.it doesnt seem to be helping much

Yea, coupled with the 10mpg problem there's something else wrong. Its not the MAF....lol

But hey...clean it anyway I guess.....lol

I think its time for a scan with a real OBDII scanner so you can see whats going with things while the engine is running.

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Can i rent one from the store or what?

Can i rent one from the store or what?

Not that I've ever seen, I think they cost like $4,000 or something like that.

The dealerships have them and almost all mechanic shops. Sometimes they charge like $15.00 to do it, but you have to have someone that really knows how to read everything. Too bad you have no speed shops around you, they would probably do it for free.

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So just go to a chevy dealer or something? I was starting to think it was just due to my short commutes before the engine is able to warm up but 30 to 13 mpg? I kinda doubt it..

You can pretty much go to any repair shop have them run a scan with a scantool.
I was charged $30 about a week ago.

btw did your car die at any point on that first cold start when you noticed the RPMs jump?

Did it do any good for you did they find what was wrong? No it didn't die it happened once and is running fine at idle now hasn't happened again

No everything was reading fine. I was hoping there was a better explanation for a code I had.

Oh shoot, well i guess ill try and find a place then with a real scanner.. Any suggestions?

Havent found a place yet that can do it.. I dont mind working on the engine though because it gives me an excuse to give my car some tlc and make sure its up and running. Still the same problem (half gas mileage) here are the updates:

Tank (with injector cleaner) almost empty at around 150 on the dummy gauge.
Checked resistance on spark plug wires and they are doing fine @ 351 ohms which i believe is standard.
Clicking sound on start up is the egr gasket i need to replace
When i have the hood open and open the throttle quick there is a pretty violent whoosh (sucking) of air...normal? I always thought this was the lid but not sure anymore.
Took off maf and lid to clean and saw that the throttle blade has some gunk (not too much) but a little build up on in. Looks like oil and dirt...normal?
I open the throttle blade and look inside the intake manifold and it looks pretty wet inside...normal?
I noticed my coolent was really low
I just remembered this problem happend half way in winter about the same time i took my ac belt off because it started squeeking really bad, havent been running it sense..maybe i uncovered a vaccum leak?

Im going to try and clean the intake parts up, get that egr gasket ordered.. Any thoughts? Thanks for the help guys, ive read alot of threads on here about bad mpg's im hoping if i can pinpoint this it might help someone else out later on too alot of the threads ive found never post the final conclusion :confused:

Heres the pics: 1 and 2 are inside of intake, 3 is the tb

Have you tried changing the fuel filter yet?

No not yet, i did it around 2k miles ago so its pretty fresh.. wouldnt that cause it to be running lean though/stuttering/weak acceleration?

A clogged filter can cause MPG issues also, but that's probably not it since you changed it recently. The egr gasket issue you have is it the large O-ring that fits around the tube going into the intake?

Do you always get gas at the same station?
If you do try a different gas station, maybe some bad gas.
FYI, Seafoam also works good if you add a can of it to the gas; better than regular FI cleaner in a bottle.

No just the one connecting the egr to the exhaust manifold on the passengers side. Yeah i wanted to check that so i got this last tank of gas at a different station and no difference.

Someone on here said that when checking the wires you want to bend them and check them too because they can show up fine normal but not work when flexed. However all of them looked good and tested out great when i did it so i dont think there the problem but i may take them off and try it again.

Im going to throw up the pics i took of the TB and inside of Intake manifold

Edit: See post above for pics

As far as checking for vacuum leaks did you try using a small hand held propane torch, just do while the engine is cold. Or have you completely eliminated A possible small vac leak ?

No i havent checked for vacuum leaks yet, still need to check that and the injectors if i can

Remove the PCV valve and clean it out really good with some brake clean, or install a new one, and see if that helps; it can't hurt.

I would think not having the egr gasket is causing a vac leak, it would be best to get that ordered soon, perhaps fresh air is getting int othe exhaust and messing up the o2s.

I was going to get that pcv valve cleaned today but i needed my car done so i could use it and didnt have time to get to it before it got dark.

I cleaned up the TB and it was very dirty, i put my finger inside the intake manifold to see why it was wet inside and it didnt really smell if anything it smelt and looked like oil..

Im going to be ordering the egr gasket soon if only to get rid of that sound on start up. When i went to the parts store they couldnt find it, ive seen two types that look like they work and dont know which.

I would think not having the egr gasket is causing a vac leak, it would be best to get that ordered soon, perhaps fresh air is getting int othe exhaust and messing up the o2s.

I agree with this guy as well. If you are getting air into the exhaust stream close/ before your o2s they won't like that too much. It will definitely think that the car is running lean and fatten up the air fuel ratio in an attempt to save your engine from going too lean (in reality its not the o2s just see what is going on in the exhaust). PCM commands the injectors to spray more fuel, you lose gas mileage. Definitely something to look into, actually any exhaust leaks near the o2s

^ Yeah im going to order one as soon as i figure out which one of those above i need.. Can anyone confirm which of those is the correct gasket?

^ Yeah im going to order one as soon as i figure out which one of those above i need.. Can anyone confirm which of those is the correct gasket?

You want the larger one on the left, the other gasket is for the air tubes on the exhaust manifolds. :nod:

Alright well, i got the air tube gasket ordered (got them mixed up and thats the one i need) thanks 99blue, should be here in 3 days or so, got my ac back on and fixed all the squeals.

I called around and the cheapest scan is done by the automotive department of my school and they charge $45/hr, called the gm dealer and the charge $80/hr, the other small shops in this god forsaken town didnt really have a clue what i was talking about (like always) :eyes: The school is booked till April though so im going to still try to pin point it myself.

I noticed today that at idle my oil pressure is around 50 and when i accelerate to 2k it jumps up to 60 then when i let of it goes back down. I know these are dummy gauges more or less but it stays constant for the most part in the past. I also have a good amount of oil on the bottom of my car, but i believe that was from when i switched to moble 1 synthetic..im pondering switching back. I dont believe this is affecting my gas though.. Going to clean that pcv valve today also.

Today I was pulling plug wires from the drivers side while it was running and it didn't make any difference on how it ran (which seams weak now days). It was arcing though on the coil so I guess they are working but yeah I thought the motor would be runnih bad. I didnt do it on the passengers side cause I have to remove the air tube to get to them.

If you weren't getting spark to the entire driver side bank your engine should have been shaking really bad, and it would of thrown multiple misfire codes.

Yeah I realized it would be very unbalence after I thought about it. This afternoon I'll just pull two ad see what happens. I just figured I would be able to notice a difference without one cylinder

Yeah I realized it would be very unbalence after I thought about it. This afternoon I'll just pull two ad see what happens. I just figured I would be able to notice a difference without one cylinder

Don't know if you ever saw my thread awhile ago when my PCM got fried. It completely took out the drivers side 4 cylinders. I could start the engine and it idles fine, not off balance at all. I could touch all 4 exhaust manifold pipes and they were dead cold, the passegers side 4 cylinders were running fine and hot. I noticed a loss in power while driving home the night before (and an occassional spit when one of the 4 would fire out of the blue), so it drove about home about 6 miles normally, no shaking or off balance, just horrible power output because half the engine was off. I waited till the next day when it was cooled off to start it again to start checking things and thats when I did the exhaust manifold heat feeler test after it idled for 1 minute.

I had one cylinder not firing once when a plug wire was not snapped on after I did a complete spark plug change....almost no difference was felt in power when I went for a ride when I was done. I didn't get an SES light either which was strange. When I saw it hanging off after I popped the hood right after a short ride, I was like WTF....I put it back on and that was that. Odd...I didn't notice a power issue. Maybe its just not apparent so much with ~500 RWHP. I never went WOT, just a normal drive for about 10 minutes.

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Yeah my phone does the same thing. But I was curious as to whatyou took off and it was clogged?

^say what?

Yeah ls6 I read that actually and that's what I was trying to figure out. My coils are doing fine they were arcing after I took the wires off, even shocked the shit outta me today haha. I forgot you felt the manifolds ad they were cold though, I should check that

you shouldnt test the spark from the coils like that. It could mess up the PCM or ruin the coils. The best way to do it on a distributorless system is to unplug each coil separately and then see if it changes. Way less risk of damage that way. Wouldnt want to be chasing down another issue you accidentally created while trying to fix another.

^Yeah it probably isnt the best way thats for sure.

Randomly yesterday my SES light when on so i pulled a secondary air and engine temp sensor codes. I have had both codes, thought i fixed the secondary air when i found it clogged with the old gasket and also i just installed a new one so we'll see if that goes away. Also the check engine light came on only after i unplugged it to do my spark plug change but i plugged it back in also and it eventually went off.

Still waiting to get it into the shop but seeing what i can do in the mean time.. Wish i could find someone else besides the school here or a gm dealer that will scan it.

Help Help running rich dumping raw fuel into engine, replaced Fuel P. reg. IAC
valve Temp sensor no luck no codes runs better when warmed up but way to
rich. Can't get started unless hold it to the floor when cold then hardley runs.
Don't know what to do 1995 firehawk with procharger this problem started
all of a sudden, need some suggestions on what to try next??????? Fuel
injectors ok .

I'd check that ECT out too, it actually has a lot of input when it comes to idle and fuel control

^That is true. Today i got readings from it and it checks out to be fine (given that the mulimeter jumped around alot and was hard to locate on the terminals) ~20k ohms cold, ~500 operating temp (slightly cooled down). Seemed like it was fine though.. I unplugged it as well and could definatly tell a difference (weaker). I also checked the wire and it had the normal 2.5V reading as well.

When i took it out to get it to running temp though there was a little "rapping" or slight knock when reaching close to 2000 rmp. It also threw the damn secondary air code so im guessing my pump is going or gone out, no big deal.

I doubt i will be able to diagnose it myself unless i just start replacing everything, guess ill have to wait till April when i can get it scanned :(

what kind of knock? Usually you hear a knock all the time if its like a lower end thing. And by that testing I'd say that pretty much rules out your ECT

Yeah it was a lower knock and after a while it quit pretty much, not too good of an ear for that stuff though.. I though the typical piston slap on cold starts was a higher ticking sort of sound.

I agree with this guy as well. If you are getting air into the exhaust stream close/ before your o2s they won't like that too much. It will definitely think that the car is running lean and fatten up the air fuel ratio in an attempt to save your engine from going too lean (in reality its not the o2s just see what is going on in the exhaust). PCM commands the injectors to spray more fuel, you lose gas mileage. Definitely something to look into, actually any exhaust leaks near the o2s

^^This^^

Brad

Well, since she got bumped..

My latest findings before leaving for spring break: I reset the pcm by unplugging the battery, when i started it up it ran like that one time i posted here before, around 500 rmp and a slow touch of the throttle bogged it down it seemed and if i went past that it would then get out the the bogged state and run normal, and when gas was let off it would dive down to 400 and then back up to 500. So low idle, caused by whatever. Turned the car off started it again, running fine. Pcm adjusted to lean condition? Common for car to "relearn" like this after resetting the battery? Not sure..

I also checked again for vacuum leaks and found nothing. I heard its good to remove the iac valve before checking though because it may keep you from finding a leak.. is this true? Either way i dont think i have one..just figured i would check again

o2 sensors cause bad fuel mileage also ck to see if the plunger on your egr valve is working. if it is stuck open or closed thats bad it should move freely . You need to defenitly fix the egr leak that will cause issues with the o2's to read the exhaust wrong and then tell the pcm to dump more fuel in, like 3 other people have pointed out.

Yeah thats been fixed for a while now, wasnt the problem either. After spring break is over im just going to be getting a full scan and it should should enough readings to pinpoint where the problem is, just wanted to get my car running right before then if i could, now its up to the scan and i just gotta wait :(

Don't pull the IAC off, itll just cause your car to go to redline.

Well guys, my car isn't going to be able to get into the shop until the earliest opening 2 to 3 weeks from today. I asked the guy what he would advise for diagnosing it and he said the shop will want to start out by fixing whatever is throwing an engine code. Well, secondary air should never cause this correct? I'm assuming now it's the pump and I'm going to pull all of that before I get a frost anyways so I don't want them throwing money there. The engine temperature sensor code has been thrown intermittent (twice) but when checked it seems fine, so maybe the wiring needs checked and or replaced.

I asked him why a full scan wouldn't pinpoint what's wrong and he said te engine codes can throw the engine into a "cold state" causing compensation in areas and this and that, bad sensor management or w/e you will. He said it alot better than me but I understand what he's saying.

What do you guys suggest I do? I hadn't been throwing new parts (engine temp, iac, front o2's yet) considering I'm at 94k maybe I should though. Anyhow, I've tried avoiding spending more than I have to by checking I stead of replacing.

Also, it just seems really weak at idle. Normal rmps but I don't feel or hear the normal kick in the ass strong running v8. Feels more like a tame v6 or something, but that could be a mind thing.

Thanks for all the help so far guys! :)

Its not the MAF.....MAF doesn't come into play until you go WOT....and its used for cold starts until you reach 122*F. I think its 122*F....either way its only used for cold starts and WOT.

Its not that.......

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the maf is always "calculating air flow" and "engine load", its not just ONLY used for cold starts and WOT...

Don't pull the IAC off, itll just cause your car to go to redline.

You can pull of the IAC, just dont mess with the "pintle" and just spray it off with "brake clean"

I replaced the iac valve today and I went for a long enought drive to check, I think it's back to normal now after my first check it showed I had gotten 30.703 mpg. Well see if it stays but I think it's fixed now! :):):):):):)

I replaced the iac valve today and I went for a long enought drive to check, I think it's back to normal now after my first check it showed I had gotten 30.703 mpg. Well see if it stays but I think it's fixed now! :):):):):):)


Did u clean up the throttle body while you were at it? i wana say that the # 1 reason these get replaced is because of carbon gets in there gets sticky..

Update: replacing iac didn't do anything, I had miscalculated my mpg by forgetting I had put gas in 1 or 2 times and not recorded it, showing that I had gone far but not according to how much I had put in. Since then, I have taken it into a shop to get it on an engine analyzer and finally see what's going on. However, I used the school's shop because it's cheap and easily accessible, but the senior they put on the job had to leave and won't be back till Tuesday in which I will go find out what he found. The head of the department said they found a misfire. I went ahead and pulled the car out and payed them in advance because at least I can work on it when it's in my driveway, however it will probably go back in on Tuesday.

I looked up causes of misfires and there are multiple reasons. I started by ordering new plug wires like I should have in the first place. Although I tested my stock wires and they seemed good, they need replacing cause my car is at 94k now, and also I did not test them bent just in a natural position. There old and need replacing. Next I've checked the resistance on each injector an there all at 130 ohms, working fine it seems (electronically that is). I want to still check the coils (accurately), get the wires on, and cover the ignition aspect of a misfire, then go from there an see how many things I can knock out before it goes back in. I want to find out what's wrong but I also want to post up what was wrong on here in case anyone has a similar problem and can follow this thread, lots of threads people ask then find the solution and never post it, (what I have found looking through). I've also had a many pm's of people having similar issues so I'm trying to say everything I have been doing so far.

Did u clean up the throttle body while you were at it? i wana say that the # 1 reason these get replaced is because of carbon gets in there gets sticky..

Oh and yes i defiantly cleaned that. I believe somewhere earlier i hopefully stated that, but good point.

Follow up: Although this problem could have been a multitude of these things, eventually it came down the the electrical wiring in either the harness and or the pcm that was causing a misfire and other random things.