New LS1 Owners - Newbie Tech - whats wrong with my car..?

its about 91degrees/60%humidity. i start my car and begin to leave school. i get into a turn around to head the opposite way and the idle is feelin rough. so im waiting my chance to turn and then get a break. as i begin to give it throttle it is hesitating to move, and then goes, and then hesitates...i give it more gas and it slowly starts to get going. i dove home and it never happened again :confused:

this has hapened b4 but was worse the first time. this time wasnt that bad. the things that came to mind were fuel filter, fuel pump, bad 02's, hot weather.

what u think?

J

Ttt...

:bang:

i know when mine did that it was the fuel pump you could always upgrade while you are at it and if its it great if not try the next thing, i doubt its the filter

befor u go and change the fuel pump u should try changeing the fuel filter

fuel filter, fuel pump, bad 02's,

Thats where I'd start. The O2s are easiet to do so I miight try that first. The cost adds up though (4 O2s @ $50 each = $200).

if it was bad o2's you would throw and ses light? right? So I doubt it is the o2's. If you are throwing codes get it diagnosed and you should figure it out quick.

sorry couldnt be anymore help.,

thats the weird thing. no ses light. i was waiting for it to come on and nuthin happened.

Bad O2s, Bad Fuel Pumps, and Clogged Fuel Filters dont always throw codes.

Although it is possible that none of those are the problem. Those are just the most likely culprits.

CAR DID IT AGAIN! it has to be the weather that is triggering this effect. its hot as fuk outside. just like before. it started doing it again after i ran a few errands. i start up the car and it starts bogging down then going then idling rough then bogging down. i throw it in N and rev it up. it revs up fine :confused: then i put it bak in D and it starts chuggin along. i get out on to the raod and its driving like SHIT! i was hoping to throw a code and I DID. i pull over let the car sit and try driving again. does the same shit. stop the car, turn it off, and wait about a minute. start it up and its fine! so i go to autozone and the cod is PO300 multiple cylinder misfire.

what do i do now...?


J :cry:

Check all the plugs... They are many things that cause multiple misfire..... do a search.. But I would chech my plugs first...

but it runs fine now. if i fouled out the plugs wouldnt it continue to run like shit?

A multiple missfire is not necessarily a permanent condition. It can come-and-go. Check the plugs and wires. Maybe there are some bad plugs or the wires are shorting or RFI is leaking in. Its also possible that the plugs and wires are fine. Other culprits are the IAT sensor, MAF sensor, and Idle Control Vavle. If it only happens on very hot days, then bad readings from the sensors or a badly operating idle control valve can cause a bad idle and part throttle. It may confuse the computer and cause a misfire (this is a guess).

RFI? will the plugs be black if there bad? is the weather playing a part in this?

Radio Frequency Interference

Its the Eletromagnetic Noise that the shielding on the plug wires is supposed to filter out (lessen anyway). If the casing has gone bad then the plugs could be arcing or if the caseing isnt that bad, RFI can leak out and interfere with other wires and cause audible noise in the radio.

i see...would it be alright to get plugs and wires from autozone?

There are others here that can better answer plug and wire selection. Plugs and wires from AutoZone aren't bad, they just may not be performace editions like Taylor 10mm wires or NGK plugs. Although there was a thread in which someone said that AC Delco (or another brand starting with "A") used rebadge NGK pulgs.

Here is a site on how to read spark plugs:
http://www.densoiridium.com/howtoreadusedplugs.php

I did some searching. Many people recommend TR55 (stock# 3951) for N/A and TR6 (stock# 4177) for Nitrous motors. Some also recommend Denso Irridiums. AC Delco (stock) and Bosch +4 are a toss-up. Some love them, some hate them. They work and they are available from AutoZone. If you need pulgs now, then a set of Bosch premium wires and +4 plugs should be fine and last longer (although not really performance oriented). Here is a link so you see what I mean: http://www.ls1tech.com/forums/showthread.php?t=49039&highlight=delco+ngk

Here is a site on how to read spark plugs:
http://www.densoiridium.com/howtoreadusedplugs.php

I did some searching. Many people recommend TR55 (stock# 3951) for N/A and TR6 (stock# 4177) for Nitrous motors. Some also recommend Denso Irridiums.


thank you for searching. i searched and found nuttin. if i autotap it could i start to diagnose the problem quicker?

I added more to the end of my post above.

Autotap (ot other logging software) will help. I have no experience with it, so I cant help you on how to use it.

just did a search and read up on it a little bit. autotap will help identify which cylinder, but as i read further people are only experiencing it in certain weather conditions like myself. i have stock wires and NGK's in there now. i am going to get some new plugs and wires, and then see what happens.
this suks :cry:

How old are the plugs? From what I've read, NGK TR55 plugs can last anywhere from 10,000miles to 30,000miles.

How old are the plugs? From what I've read, NGK TR55 plugs can last anywhere from 10,000miles to 30,000miles.

i think they have 10k.im gonna chekm b4 i spend anything.

i think they have 10k.im gonna chekm b4 i spend anything.

Good idea. No need to spend money if they are fine.
Use the site I posted to diagnose them.

i autotapd the car and found out that 3,5,6 cylinders had a ton of misfires....
3=460 misfires
5=290 misfires
6= 1190 misfires

i autotapd the car and found out that 3,5,6 cylinders had a ton of misfires....
3=460 misfires
5=290 misfires
6= 1190 misfires


TTT...which cylinder is which? i am going to check the plugs but i am not sure which cylinder is 3, 5, 6. what is the order?

thanks J

I'm not sure actualy. I think number 1 is the front driver and number 8 is the rear passenger. Other than that I dont know the numbering scheme (like which one is number 2: passanger front or second front driver?) I've tried searching, but so far nothing helpful.

Anyway, if you find problems with some of the plugs or wires, replace them all so there are all fresh and perform the same.

Assuming it's the same on the GTO as the f-body (and I think I remember reading it here before that it is), it's:

8 7
6 5
4 3 <-driver's side
2 1
Front

Dan

Its the same engine (basically), so it should be the same pattern.
Thanks for clearing it up. :cheers:

i autotapped it again today...3,5,7 had high misfires. would something have to do with that order as to why just those cylinders misfired? 3,5,7 are all on the same side


J

I dont know.

Jay,
I hate to be the bearer of the obvious, but when multiple cylinders misfire, it's almost always not plugs or wires. The plug readings might tell you what you already know...that the darn thing isn't firing! If the side is misfiring, it is probably one of 2 things (or both): that side's O2 sensor is degraded (but not yet to the point of locking in a SES light) or a fuel injector/fuel rail /regulator issue. If you have miisfires on each side, that would point to the regulator.
I had a similiar experience with my truck. Turned out to be bad gas combined with fuel injector cleaner. As soon as I refilled the tank, the problem went away.
HTH,
Todd

Jay,
I hate to be the bearer of the obvious, but when multiple cylinders misfire, it's almost always not plugs or wires. The plug readings might tell you what you already know...that the darn thing isn't firing! If the side is misfiring, it is probably one of 2 things (or both): that side's O2 sensor is degraded (but not yet to the point of locking in a SES light) or a fuel injector/fuel rail /regulator issue. If you have miisfires on each side, that would point to the regulator.
I had a similiar experience with my truck. Turned out to be bad gas combined with fuel injector cleaner. As soon as I refilled the tank, the problem went away.
HTH,
Todd

sooo. should i check the injectors?

Jay...

This really sounds like an 02 sensor problem...mine did this when I first put my headers on. We need to get together and plug my Tech 2 into your car. If you are having misfires like that you could be having what is called "sympathy" misfires....you will have alot of misfires on one bank, and the other bank will misfire too becuase the other side i being f*ed by the other (kinda hard to explain). This makes it hard to find what side is messing up, but an easy way to find out if its an 02 sensor is to plug the Tech 2 into it and take it out of closed loop mode...this will run open loop, and if the car stops misfiring, it is one of your 02's. Like todds87ss said, it is unlikely this is becuase of plugs/wires. Dont take it to the dealer yet until we find out if its your 02's, because they are easy to change out.

-Brian

I guess it could be the O2s. They are easy to replace, but the price creaps up. ($50 each X 4 = $200)

I Just fixed my car doing the exact same thing and posted about it in this section of the board, I got no responses. That seems to be a common thing I have noticed on this board, Someone asks for help or posts something about a problem and how they fixed and 6 people view and never respond.

Anyway my problem was my passenger side 02 plug was melted against my header and grounding out while at the very same time my drivers side 02 had rubbed against something and ripped the wires up. Both of them were messed up. Anyway fixed the plug and replaced the other and no problems since, and it was hesitating BAD too. WOuld idle just fine but give it gas and it would fall right on its face and then come out of it like nothing was wrong.

I Just fixed my car doing the exact same thing and posted about it in this section of the board, I got no responses. That seems to be a common thing I have noticed on this board, Someone asks for help or posts something about a problem and how they fixed and 6 people view and never respond.

Anyway my problem was my passenger side 02 plug was melted against my header and grounding out while at the very same time my drivers side 02 had rubbed against something and ripped the wires up. Both of them were messed up. Anyway fixed the plug and replaced the other and no problems since, and it was hesitating BAD too. WOuld idle just fine but give it gas and it would fall right on its face and then come out of it like nothing was wrong.


yup. same thing here. it did it today again! :bang:

brian. check your PM's

u da man

O2s are what I said to check first since they are so easy. Did you check them?

O2s are what I said to check first since they are so easy. Did you check them?

Yeah, we checked them, and I dont know if they are bad or not, because i guess it only happens when its really hot out, or the engines really hot. I kinda was thinking it had something to with his A/F gauge because it is spiced into the side that was showing the problem...but i dunno :(

-Brian

it started doing last nite.....hence it was cold out so now it happens whenver. hot or cold. i changed the O2 that spliced into the A/F. so far so good. lets see what happens. thanks to everyone who has helped so far. u guys are awesome. big shot out to brian for helpin me out with his TECH2. :hail:


J

i changed the O2 that spliced into the A/F. so far so good.

Thats good.

Could it also be a bad splice that is causing a bad signal to the computer? You are basically adding resistance to the line, which can give the computer a different reading.

Well.... Its been a couple days.

How's it doin. Did you check the splice to make sure its good?

Well.... Its been a couple days.

How's it doin. Did you check the splice to make sure its good?

its all good. nuthn been fukn up. i think we solved it. thanks for the help. u da man

you're welcome :cheers:

Jason,

Hey man. I had similiar problems a few weeks ago and I JUST got it fixed for good last week. My problem was intermittant and the misfires only seemed to happen during the warm up phase of the car, and often when I would shut it down for like 5 mins and restart it back up. We did a lot of things trying to find the culprit. We scanned for codes and saw that the front o2 sensors were bad. Replaced them. Problem was almost fixed but it still misfired briefly during quick shutdown/restarts. The tech I finally went to believed the computer may have been defaulting to a specific "program" or fuel curve that was sometimes flooding the cylinders, because I had so many error codes - I just took out my EGR, AIR, put in headers, no o2 sims, etc. They also said my wires looked kinda bad and replaced them. My problem is gone now thank God. Hopefully yours is too. If it comes back though be sure to look into all the things I mentioned here - if you haven't already.

Hey!
I would get me some real good injector cleaner (the kind that works in one tank of gas) and fill up your tank with some chevron premium a couple of times. I wouldn't get to excited for about two weeks and see how it goes.
See Ya!
Tony