My car "92 Camaro TBI 5-speed" has started running poorly when it gets hot, it kind of stumbles or has a jerkyness when I accelerate at anything more than 1/4 throttle, and feels like it's way down on power too, but in the morning when it's cold it runs like a millon dollars and is very smooth and has lots of power, well for a RS anyway. Any ideas on where to look for the problem. It has a new tuneup and the temp sensor was replaced last year because the gauge was reading wierd, Thanks

 

Welcome aboard!

Do you know if the 02 sensor was replaced with the tune up. Most shops do not replace the 02 when doing such maintenance. I would also have a look at the base timing to make sure that it hasn't slipped over time. It sounds like your porblems are 02 related. If the sensor looks old and rusty (driver side exhaust manifold) than it needs to be replaced. A bad 02 will cause a lot of problems and not always throw a code.

 

The O2 sensor was replaced about a year ago when I had the exhaust replaced, it had a new high flow cat installed at the same time. I know quite a bit about cars by watching my dad for many years and I have checked the base timing with the advance connector unpluged and I have it set 3 degrees advanced because it runs better that way, but the sticker says it should be at 0 deg. I do get a code once in awhile while crusing down the road, I jumped the diagnostic port and I think it flashed a code 32 which I looked up as a EGR code, but it goes away when the car is shut off and restarted. By the way the car has 170,000 miles with all the original sensors except the O2 and temp.

 

It may be either your igniton coil or pickup coil or both...

 

If you get a code 32 your EGR valve could be stuck open. Your problems could also be ignition related. With that many miles it is hard to focus on a single area. You may want to get your hands on a volt meter and start checking ignition compenents. I would still focus on the EGR since your ECM keeps throwing that code.

 

prob ur coil gettin heat soaked, move it to the firewall

 

Coils don't perform any different when "heat soaked" to warrent a change in location.

 

had that prob on my tbi motor, when i put it on the firewall it ran even better. idk im still new to the tbi stuff, im used to carbs and non-computer cars

 

Have you checked teh CTS? Thatll cause those syptoms if the resistance is overly high. The ecm will think its 'cold' out and give the engine way too much fuel.

 

Good point. A CTS is easy to test and all you need is some hot water, cold water, thermometer and an ohm meter. There are resistance values for certian temperatures that you can varify your readings with. A search should bring up a chart with those values.

 

CTS, is that the coolant temp sensor? Is that the one by the thermostat housing? If so it has been replaced.

 

Ok, the other possibilities could be a bad modue, or maybe a failing fuel pump. I would say its probably not the egr causing the poor hot performance. If it was stuck open, the engine would run poorly at all temperatures, and usually this would only be at part throttle.

 

Shifty, didn't you mean Welcome a broad? J/K Fastchick, no disrespect intended.

Do you have access to a laptop? If you do you can download a program called WinALDL(click here). You will have to make or buy a cable to connect the laptop to your cars aldl port then you can data log your car to see what is happening as the car runs poorly. The program is free and the cable will cost you about $10 if you build it yourself or about $30 and up if you buy it already made. After you have a datalog of the problem you can have some of the people here look at it and maybe find out what is going on.

Steve