HELP!! 1991 L98 idle problems..........

[madcityman123]

I have a 91 convertible that is running like crap. When I start it up it might idle at 1000 rpm kind of smooth, but then when I press the gas even lightly it chokes out? I will run it for a few minutes then it might just die and when it dies I hear a squeal from the engine? I am guessing fuel injectors? When I jumped the diag with a paper clip, nothing comes up except 1, 2? What code is 1, 2?

 

[LT4man]

A Factory Service Manual would give you a step-by-step diagnostic schematic to follow. Go here: http://www.helmsinc.com

1,2 means 12. Everything is A-OK. Any other number (combination of dashes) would indicate a trouble code.

Sounds like a good Throttle Body cleaning & Idle Air Control motor cleaning would point you in the right direction. Search here for a Minimum Idle Air adjustment procedure and follow the instructions to a "t"!

With these simple maintenance items performed, you should be breaking the rear tires loose anytime you floor the gas pedal!

SAVE THE

 

[madcityman123]

Still confused

Thanks for the help so far, but I am still confused? Why would it run like crap, even die on me over and over, but still flash code 1 2 every time I check? There is obviously a problem with my engine, heck I just tried to start it and now it wont start. It starts better cold sometimes definitely than hot? If I start it and keep my foot off the gas it idles on it's own, as soon as I touch the gas pedal it chokes out and dies? It has to need more than a cleaning doesn't it?

 

[sstearns2]

Thanks for the help so far, but I am still confused? Why would it run like crap, even die on me over and over, but still flash code 1 2 every time I check? There is obviously a problem with my engine, heck I just tried to start it and now it wont start. It starts better cold sometimes definitely than hot? If I start it and keep my foot off the gas it idles on it's own, as soon as I touch the gas pedal it chokes out and dies? It has to need more than a cleaning doesn't it?

I would definitely start by pulling the throttle boday off and cleaning it out. It doesn't take much gunk in there to start messing things up. You could start by just taking the intake duct off and wiping out the bores and the throttle plates as well as you can with the TB on the engine and seeing if that helps, but in the end you'll want to pull the TB and take it apart and clean it really well. I'd do it every 10K miles or so to keep it idleing nice.

You can check the injectors by unplugging them and measuring the resistance across the two pins. It should be 16 ohms. If you're still running the original injectors then you'll probably need to replace them at some point. They don't like the ethanol in the fuel these days. There are a bunch of threads on injectors if you do a search.

Good luck....

Scott

 

[madcityman123]

Thanks Scott. Where can I find directions for throttle body cleaning/removal? I am a neophyte corvette mechanic, but I am gonna learn!

Thanks

 

[LT4man]

Why would it run like crap, even die on me over and over, but still flash code 1 2 every time I check? There is obviously a problem with my engine, heck I just tried to start it and now it wont start. It starts better cold sometimes definitely than hot? If I start it and keep my foot off the gas it idles on it's own, as soon as I touch the gas pedal it chokes out and dies? It has to need more than a cleaning doesn't it?

While accumulating close to forty (40) years experience in the auto & truck mechanical repair industry, I have learned quite a few things.

The computer will trip & record a DTC (Diagnaostic Trouble Code) whenever it sees a controlled emission value go outside its stated parameters. In simple English, this means the computer is only looking at and adjusting areas to do with the emission controls on your engine.

If you have done diagnostic testing & only have a #12, this is very good. This means your computer & all of your emission control systems are working.

Without any DTCs being set, we can now move our diagnosis about your problem to the most simple issues which arise with these vehicles.

Your Throttle Body is one of the most ignored areas which can be causing all of your starting & running problems.

If you do a search on this site for "Throttle Body Cleaning", you will come up with many threads showing you how to do this simple repair.

You are going in the right direction. You just need to continue your journey, Grasshopper!

WILL SOMEONE JUST SAVE THE