chich12

Brought my car into meineke thinking i needed a new catalytic converter, but when he cut before the cat on the y pipe he said the same thing was happening. It is still bogging down when warm. Its been going on for like 3 weeks. It will take 5 turns usually to start the car up and then it will run OK. If i let it sit for about 30-45 minutes it will still take a while to start and then run like crap. It will fire up, but either die or try to idle at like 500 or less. When you give it gas it just dies. It seemed like the cat was the problem. At first i thought i put a bad tank of gas in there, but the problems didnt occur randomly. Only when it was warm. Would this be ignition or fuel related. No engine codes either. I have to wait till Monday to bring it in. I still have a couple years left on my warranty, but wanted a heads up on what the problem is.

Thanks, Eric

LT4orbust

sounds like you better ck fuel pressure, cats won't cause it to not start at akll

69gto96z

I was having the same problem when I installed a new ECT in my waterpump, then one day my fans quit coming on again and the bogging quit. It makes me mad, but oh well, atleast I can drive it now with my fan switch.

chich12

Does fuel pressure differ when an engine is warm and when its cold? This problem has literally occured 7 out of 7 times. It will drive OK when i first drive it. It will sit for 4 hours. Take a little while to start but drive OK. Then i let it sit for about 30 minutes. Take a little while to start again and then just fall on her face. Then it wont start. Then i can come back to it in like 4 hours and it will still take a while to start but i can drive it. This is usually around my work schedule as you can see the time increments.

Thanks, Eric

Bad AZz Z28

Check your ignition control module. A $17 part that attaches almost directly to the left cylinder head and might be affected by the heat once warm. If it is defective, feel free to shim the unit out a bit with some washers.

From there, check opti. Coil, wires, and plugs are also all possibilites. If it only happens when warm then it is less likely to be a fuel problem, but ya never know.

chich12

I have been searching through the forums and mainly lookin at the ICM. Would problems with the ICM throw a code out or what? My engine light has NOT come on once during this whole problem. Can the ICM malfuntion both at cold and hot temps? I picked my ride up at the muffler shop and it started right up. Never seen that happen before. Usually it takes about 3-7 turns to actually start either cold or hot. I am just debating whether or not to try the ICM mod. I would think it would throw a code if it was malfuntioning.

Thanks, Eric

chuckd4more

I could be mistaken but I think $17 is WAY off for the ICM. If I recall it runs about $65.

Netwrkengeer

With out a doubt ICM is like $65+, I would say Coil $17... anyway check out this thread http://web.camaross.com/forums/showthread.php?t=371298
and contribute we are having the same problem, I think we are about to figure it out due to the fact that combined we have changed almost everything.

chich12

[QUOTE=Netwrkengeer]With out a doubt ICM is like $65+, I would say Coil $17... anyway check out this thread http://web.camaross.com/forums/showthread.php?t=371298
and contribute we are having the same problem, I think we are about to figure it out due to the fact that combined we have changed almost everything.[/QUOTE

Thanks for introducing me to that thread. Now i have a list a mile long. LOL I bought my ride from Carmax and still have 2 years left on my warranty, but am afraid to bring it there. When i first did they told me it was the catalytic converter. I brought it to meineke and they said definilty not. I plan on bringing it in Monday to carmax, but dreading it. Im not too sure i trust them with all these things. I do not think they are that familiar with LT1's.

The only main thing i see that is different with everyone else's problems, is that mine always takes a while to start. It doesnt matter if its cold or hot. I can drive my car for about 10-45 minutes and it will still drive OK. Its when i try to drive it like 30 minutes after its been sitting. Thats when it bogs down. So it doesnt happen right away. It only happens if the car sits and then restarted.

Thanks, Eric

Netwrkengeer

OK, have you changed the fuel filter it is pretty cheap and sounds like a quick fix for your problem.

I would also ask your mechanic (if you decide to bring it to him) to check the Fuel pressure first.

chich12

Is any component of the fuel system affected by heat? I only notice the bogging when my car is hot.

thanks, Eric

Netwrkengeer

There are many things but one thing that comes to mind is I have heard that in hot weather the gas cap may lock the tank out and create a vacuum. Try just taking your gas cap off when you have the problem.

Let us know what happens

chich12

Took it in today and supposedly i need a new fuel pump. He said when it got hot I was only getting about 15 psi. I am just hoping that fixes everything. Its under warranty too so its not that bad. Thanks for the help everyone. Later

slopokrodrigez

Our cars don't vent through the gas cap. They have a seperate vent line that goes to a valve in front of the axle, clipped onto the body behind the rear seat near the connector for the fuel pump power and tank sending unit. If that breather where bad, the tank could be under vacuum.

Certainly if you removed the cap, it would break the vacuum but an unknowing person may come to the wrong conclusion that their gas cap where bad when in actuallity, it's the vent valve.

In the case of the vent valve being stuck shut, you will get the horendous odor of fuel.