Hi guys,

I posted recently as having a problem with my car. I was throwing a P106 code and Running like ***. Under load it just stumbles and has absolutely no power. And at Idle, It was just being a plain PITA. Upon further inspection i found a gash in my PCV hose. So i redid the whole thing and installed it.

Now, It seems to be better in the higher RPM, and doesnt seem to be as stumbly. I havent taken it out yet though, Since my idle keeps going to around 2K or so. I think i may have only fixed a part of the problem. I dont have HPTuners either, but the tune in the car has been working flawlessly for over a year now.

Is there anything at all i could look at to see what is causing my Idle to shoot up to 2K~ and stay there, even if i rev and let it come back down it will sit right back at around 2K.

Also, not sure if it is related but i felt where the O2 goes into the header and i could feel exhaust coming out there. not sure what that is yet, But i just want to get her back up at the moment.

Any help is apreciated guys. Thank you

Eric

 

Exhaust leak will make a tune car run funny big time. If its leaking around the o2 then you need to fix that. Also check your tps sensor on your t-body some times they need to be clean.

 

Oh and the mass air meter check that also.

 

will do. I also drove it a min ago, and it is backfiring pretty good between shifts. Even at like 2500-3000. i will take a look closer at the exhaust tomorrow. It isnt throwing any codes now so im sorta lost, but i guess its a good thing lol

 

May be a spark plug has popped off? Mine did that after I upgraded my plug wires and it ran like *** and back fired out the pipes!

 

UPDATE: ok, i just got done checking the MAF, plug wires to ensure they are on and any visible thing i could see. The MAF even got descreened while i was in there. It actually threw a pending P0106 on start but it never surfaced. it held idle OK, and ran alot better. however, it is a heads and cam car and i couldnt get it to spin forst the one time i tried. It is just wayy down on power, and the backfires were alot more rare today although, they were there.

Is there anything else easy i can check? if not i will just pull the plugs and give it a shot that way. It feels like i could have lost a plug or two.

long story short. Better idle, No more smoke, still down on power. plugs next?

 

ok update again, i changed the plugs and took it out again. ran alot better but still down on power. it just seems like its not there. it used to spin all the way through first and half of 2nd. now it wont spin at all. i am at a loss.. could it be the o2's? i am not gettng a code for them but i dont know at all what else it could be.

 

actually, looking at the plugs, Number 2 looks cleaner than the others. looks like it has fuel on it too anyone? im gonna pull the new one out of 2 tomorrow and see if it is the same way

 

A partailly plugged up Fuel Filter may cause a high idle n midrange stumble.

Do you have any sort of a vacuum leak ?

 

i looked on the vaccuum lines around the manifold and whatnot and besides the PCV vaccuum line that is now fixed, there is no leak. is there any other common vaccuum lines that i should look at? I believe it has had a pending p0106 a couple times since i fixed the first leak. indicating another one, but i am not sure on where to check. I may throw in a fuel filter today or tomorrow and see if that helps.

 

also, just FYI. the car has high flow cats on it. Could a clogged cat be the culprit? if so wouldnt i get a code? I believe if it were either of those i would have a code, correct?

 

fuel filter going in today.

 

i know...still replying to myself. OK, put in the fuel filter and drove the car. running a whole lot better. not 100 percent but better.huge thanks to david. Still something up though. It will spin the tires again now and it will idle OK but idle goes up sometimes. It threw a pending 1153 code today as well as another P0106. So tomorrow a new Passenger O2 goes in and we will try to find a vaccuum leak. anyone know a good place to look for a vaccuum leak that may not be very obvious at first?

 

Broken valve spring would be my guess.

 

^^ Why was this done? You do know if your MAF table was tuned you just threw off the tune by doing that. I really wish people would stop reccomending descreening the thing. IMO it creates more problems for like 1/4 HP your not going to outflow the thing with the screen in it unless your pushing serious power and at that point you probably should go SD anyhow. Your not gaining notable power from it either, probably the equivilent of taking off your shoes for weight savings.

You need to take care of your known problems before throwing more parts at it. Your throwing MAP sensor codes, your O2 bungs are leaking, you may have a vacuum leak, and now your passenger O2 is not switching.

ALL of those listed can cause a high idle. You NEED to get the bung sealed up to the O2 right that may cure the idle AND the switching code your getting, hopefully you haven't cooked the O2 sensor by now by not doing it sooner. You also need to go get some carb cleaner and spray around the intake and hoses to look for a vacuum leak, when the idle stumbles you found it. The MAP may need to be replaced at this point unless you know how to check them to make sure it's still good.

Once you get those fixed THEN start looking for other things. Your IAT, and MAF may need cleaned, may need new plugs and wires, O2's may need to be replaced, and if it's still messed up then I would open up the covers and start inspecting the valvetrain.

Start with cheap easy stuff and work your way up, no sense in chucking lots of money at it to find out that a simple vacuum hose needed replaced.

 

agree with you 100 percent. The maf got descreened because i run a dry shot and i have had it freez up on the screen before. more of a future thing than anything. I am going to take a look at the bung today on the passenger side since that is where i am getting the code for. I am also getting a new O2 for good measure i think.

As far as the vaccuum leak, I will start looking closer at that as well. maybe i skipped over something. now, the MAP sensor, is what i am hoping it will not be. I dont want to have to pull my intake just yet. but if that is the problem, so be it.

I have gotten tremendous help thus far from LS1tech. Honestly, I am happy that you have given me more to look at. Thanks a lot man, i will be sure to post up after i look at all these things

 

Vacume spots are

map sensor behind the intake.
the little line below the map facing the passenger side for the ac vents. A quick check for that is to see if air is blowing out your vents on the dash .
the intake manifold where it mates to the head you will have to use carb cleaner to see if the rpm jumps spray at the bottom where the intake mates to the head.
Pcv valve located on the passenger side of the intake at the front next to the throttle body
Make sure there is no air coming in after the maf that dosent go through the maf. Ie the silicone couples.
If your car as the AIR injecton system still hook up make sure the gaskets to the exhaust mainfolds or headers are not leaking, Make sure the distrabution block located at the rear of the driver side head hoses are not leaking. these hoses are rubber and when that block fails it lets hot exhaust iinto the rubber lines.


Other things to check the p1153 switching code is the cooling of the o2 sensor or sensors is not holding the correct heat to maintain closed loop mode. I battled that problem years ago. The way I fix it was with bosh o2 sensor ppart number 13111 rear o2 for the 1999-2002 corvettes. I also move the o2 bunge closer to the collector. I heard of success stories from guys who wrap the collectors with header wrap.

I would also check the wires for the crank position sensor located above the starter those wires run close to headers and my have touch.




Potential Symptoms

The following could be symptomatic of a P0106:

Engine runs rough
Black smoke at tailpipe
Engine will not idle
Poor fuel economy
Engine misses at speed
Causes

A P0106 could be caused by:

Bad MAP sensor
Water/dirt intrusion affecting MAP sensor connector
Intermittent open in the reference, ground, or signal wire for the MAP sensor
Intermittent short in the reference, ground, or signal wire for the MAP sensor
Ground problem due to corrosion causing intermittent signal problem
Bad PCM (do not assume the PCM is bad until you've exhausted all other possibilities).
Possible Solutions

Using a scan tool, watch the MAP sensor value with the key on, engine off. Compare the BARO reading with the MAP reading. They should be roughly equal. The voltage for the MAP sensor should read approx. 4.5 volts. Now start the engine and look for a significant drop in the MAP sensor voltage indicating the MAP sensor is working.

If the MAP reading doesn't change perform the following: 1. With the Key on, engine off, disconnect the vacuum hose from the MAP sensor. Using a vacuum pump, pull 20 in. of vacuum on the MAP sensor. Does the voltage drop? It should. If it doesn't inspect the MAP sensor vacuum port and vacuum hose to manifold for a restriction of some kind. Repair or replace as necessary. 2. If there are no restrictions, and the value doesn't change with vacuum, then perform the following: with the Key on and engine off and the MAP sensor unplugged, check for 5 Volts at the reference wire to the MAP sensor connector with a Digital Voltmeter. If there is none, check for reference voltage at the PCM connector. If the reference voltage is present at the PCM connector but not the MAP connector, check for open or short in the reference wire between MAP and PCM and retest. 3. If reference voltage is present, then check for existing ground at the MAP sensor connector. If it isn't present then repair open/short in the ground circuit. 4. If ground is present, then replace MAP sensor.

Related P01

 

UPDATE: after all that still having problems. We checked all the lined with carb cleaner and didnt see any noticable difference. Then i tightened the manifold down just to be sure. Also threw in a new air filter as the old one was shot. Since then i have not seen the vaccuum code once. now im showing a 0102 and 0101 occasionally. The 102 is there much more often. Now, i know i descreened the maf and put in an oiled filter so i cleaned the maf with cleaner and tried again. same thing

So, now where? I believe i will check the Sensor fuse first and then go from there. I dont want a new MAF but if i have to buy one i have to. and 1987Firechicken i know you will love this man haha. But i very well may have fucked up my maf. Any more ideas?

FWIW, i do believe the vaccuum problem is fixed thanks to you guys!

 

Easiest way to check to make sure it's the MAF is to unplug it and see how it runs .... except in your case it may not be that easy. Hopefully when CMS tuned your car, they actually put some time in the VE table, if they didn't and just scaled the MAF then you won't really know. Unplugging the MAF will use soley your VE table for airflow and fuel managment taking the MAF out of the equation. If it runs good without the MAF and crappy with it, then it's probably your MAF is done.

And no I'm not happy that I MAY have been right. Those ****** things arn't cheap and it sucks *** to know that you may have ruined a decent part. I did the same thing on my 87 TA. Took out the screen and felt NO power increase, but I didn't have any issues with it after I removed it thank god.

The screen isn't made to catch bugs and ****, it's there to smooth out the air over the entire sensor, like the screen in your water faucet works. Take it out and you disrupt it, sometimes throwing codes, and sometimes throwing unmeasured air in your motor just like a vacuum leak.

Sorry for the lecture but since I got into tuning (HP Tuners) I really cringe when people say they took the screen out. If you don't want it in there then just do like I did and take the whole thing out and run SD.

 

What torque spec and tightening sequence did you use?

Or was it done by feel, in which case you didn't do yourself any favors.