Kolk1

Ok last week I did the spark plugs, used Autolight AR472's. Now at idle, only while in gear, it will randomly bog a little, and sometimes die. IT does it very slightly in N and park, but not enough to die. While driving the car runs perfect, I even raced another LS1 and it was the same result as it was about 3 weeks ago. Ive talked to a couple people about this, they think possibly a vacuum leak or a loose connector. I just got done regoing over the whole motor, and cant find anything. The first day when i only got the drivers side done and the first plug on the passenger side, it was doing it after that, so i dont think it has anything todo with the rear plugs on the passenger side or anything in that area. But now that all plugs are changed its still doing it. Can anyone help me with this? Its a 2002 Camaro LS1, Thanks.

sgtjed

Might change plugs. I have the Autolites as well and next payday they are coming out cause my 2000 is doing the same thing as yours at idle and it didnt start until I changed plugs.

I am just gonna buckle and get the Ngk Tr55,like everyone else here is running.

SMAX

iTrader: (11)

i dont think it is the plugs, unless they are gapped to far. i have the ngk's and i gapped them at 50 like everyone on here told me to and when i got it dynoed they told me to regap them to about 40 because i was getting plug blowout on the top end. i think this may be the cause for the idle issues also. my car hasnt died but it will just bog every after i have been idling in gear for more than a couple seconds and it does it at a regular interval.

Kolk1

Mine are gapped around 35. And it doesnt bog consistantly, its just a random bog after ive been idling a while in gear, so i just slip it into N if i think im going to be waiting a little bit. And here the thing, I also just raced my buddys modded TT 300zx, normally he beats me top end, this time we where side by side. So i know im not slower. Ive been thinking its almost more of a vacuum leak, but i cant find any leaks.

99Hawk262

iTrader: (19)

My car does this too. It runs great, but bogs and the RPM's are erratic while in gear or in neutral. It will jump around, then idle nice and smooth, then bog way down and be erratic again. I have NGK TR55's that I am going to swap this weekend. Hopefully that helps. I'll post afterwards and let you all know what happens. Also, what is a good gap for a stock engine? LT's and offroad Y are coming in two months.

SMAX

iTrader: (11)

i am going to clean my throttle body, hunt for a possible vaccuum leak, and regap my plugs this weekend.

technical

By any chance were any of the wires particularly hard to remove from the plug?

SMAX

iTrader: (11)

not that i can recall. why?

Cody Brooks

iTrader: (2)

if a wire got damaged it could cause a very hard miss and would only do it at certain times and loads.

Kolk1

All of mine where about the same, some where just at alot odder agles so they seemed harder.

technical

There's a chance that you either damaged a plug wire, or possibly didn't seat the boot entirely on the plug when re-installing.

Cody Brooks

iTrader: (2)

By the way for those with misfiring problems that want help here you go

SYMPTOM : If it misses only at idle but not under load then it is not spark related.
POSSIBLE FIXES: clean injectors, (helps to have a scan tool with a misfire graphic to determine if it is missing cause alot of things can be mistaken for miss.)

SYMPTOM: If it misses under load light load or heavy load doesn't matter then it is spark related.
POSSIBLE FIXES: replace plug, replace wire, (STRESSING IN THE CASE OF LS-BASED ENGINES THAT THE FOLLOWING IS VERY RARE AND IS NOT LIKELY OR RECOMMENDED TO TRY UNLESS REPLACING PLUGS AND WIRES DOESN'T FIX MISS) coil or coil signal wire from PCM, o2 sensor VERY RARE.

WAYS TO DETERMINE WHERE THE MISS IS: scan tool and the old school way which is to pull the plug wires off of distributor or coils in this case and stick 1 inch pieces of rubber hose into the end of each plug wire and replace onto coil.
IMPORTANT: Operate the engine in the way that GETS THE ENGINE TO MISS. You may need a buddy to power stall the engine just enough to make it miss and not melt your tires off. use a test light hooked to a ground to probe near the rubber hose pieces to draw spark away from the plug and grounding it through the test light.
All cylinders that are not misfiring WILL cause a change when the spark is drawn away from that cylinder since you basically created a miss on a cylinder that wasn't before making the engine run even rougher. cylinders that are missing WILL NOT cause a change. This test will be hard on a ls-1 since the back cylinders are under the cowl but this is the way to do it if you don't have a scan tool or your vehicle is too old to have a diagnostic port and is a very effective method if done correctly.

SMAX

iTrader: (11)

all the wires are brand new, seated all the way and not damaged so i am leaning towards dirty injectors or maybe the throttle body is dirty. i understand there is an idle hole or something that sometimes gets build and will make the car idle low?

Kolk1

SYMPTOM : If it misses only at idle but not under load then it is not spark related.
POSSIBLE FIXES: clean injectors, (helps to have a scan tool with a misfire graphic to determine if it is missing cause alot of things can be mistaken for miss.)

This sounds most like it, but that it happened the same time i did the plugs is a little odd, unless the smaller spark plug gap made it more obvious to where it got my attention. I cant believe i would already have a injector problem, i just hit 22k miles.

Cody Brooks

iTrader: (2)

mileage is not the factor in clogged injectors, where you buy gas is. I saw a guy with a denali that had clogged injectors we removed the injectors turned them upside down and dumped the dirt that had collected inside the screen in the injector and used brake cleaner to remove the rest of the dirt and sand, made them as clean as new ones. a week or 2 later he was back same thing. we pulled the tank and there was alot of sand inside it cleaned out the tank, replaced fuel filter, injectors and cleaned out all the lines and its been about a month and a half hasn't been back yet. I'm curious to see how long it takes before he gets enough dirty gas to plug up his fuel system. I saw an impala come in with 9000 miles and it had clogged injectors. my car has around 88,000 miles and never has had a problem with injectors, but I'm carefull about where I buy gas and I buy premium which generally has more detergents which helps minimize (or so everyone says) the likelyhood of clogged injectors.

HAWKMAN_

I had this problem last fall just as the weather started to cool here in mich. my Car only had 22,000 miles so I never thought it was plugs and wires just figured it had to be gas related. Quick cheap fix Gumout (gray bottle) fuel system cleaner and 10 gal. of 94 octane worked for me. All gas has some sedament in it especially if u happen to get gas from a station that is running low in their under ground tanks or just filled them up. I can only assume this is what happen to me. But my car also sits in the garage a lot so it could have been related to this. I learned you should do this at least 1 or 2 times a month anyway. I was only doing it with every oil change or 3000 miles or so. Anyway, hope this helps.

technical

Injectors and ignition can cause both problems. A miss at idle can be a worn plug or wire that magically starts to work under load. I've seen this in many cars. A miss under load can be a clogged injector that can't keep up with demand. I've seen this in many cars as well. Don't fall victim to believing those rules are absolute.

Of course with that said, it could be a "rolling lean miss" caused by dirty injectors.

Cody Brooks

iTrader: (2)

I didn't say that those are absolute but 99.9% of the time what I said is true. In anything haveing to do with problems such as this there is alway an exception to the rule, but for the most part following those guidlines will get your problem fixed quicker and cheaper than random guessing or taking everything apart and inspecting everything.

technical

That's my point. It's much lower than 99.9% of the time. It could easily be either.

gwj

"Mine are gapped around 35."
I'm not familiar with the autolite plugs, but unless you're running a serious power adder, you don't need that small a gap. In any event, you shouldn't deviate more than about .010 from the recommended gap setting of that particular plug. If you need to run a smaller gap there is usually a plug with the same heat range that has a the gap range you need. For example, NGK TR55s come gapped about .059, NGK TR5s have a much smaller gap.
Hope this helps.