Hello.

I own a 1992 Camaro RS with a TBI 305 V8.

Lately my car has been surging, sometimes idling roughly, and bogging down/missing under acceleration. It does this taking off and when applying more than the slightest throttle while driving. It seems to run smoothly once up to speed, but lacks power. This problem eases some once up to operating temperature.

The oil was just changed, and new plug wires installed today. I've used fuel system cleaner, and have checked the filter and pump. No problems. The plugs are less than six months old and look to be in slightly used but fine condition. I don't have a cat. converter to be stopped up, and the exhaust is only about 2 years old. EGR seems to be fine, and the only error message I receive is #24, which is the speed sensor that has been out since I bought the car. The dist. cap isn't cracked and the terminals have been cleaned. Air filter is new, also.

Could it have jumped time? How can you tell if this has happened? I know that would be a moderately difficult fix, but is it possible to do without pulling the engine? Everything underhood seems crammed in there.

Any replies are greatly appreciated. If you want, you can probably find the car in the pictures area. Thanks again to anyone who posts a reply.

 

Sorry, the reader's rides section just isn't working for me at the moment. It's a tech difficulty, not a know-how thing, so I don't know when it'll be up.

Anyway, this reply is to ask if anyone knows of a previous post that is similar that I could be directed to. Thanks again.

 

Is your cat converter clogged?

 

Don't have a cat.

 

check your timing. Not hard to do. Also make sure your air filter is clean.

 

I'd leave the timing alone. It doesn't just up and change.

You've got either a bad coolant temp sensor, or damaged wires going to it, in either case causing the ECM to think that the engine is much hotter than it really is; or a fuel delivery problem.

How have the fuel pump and filter been "checked"?

Look at the CTS and its wiring. Try replacing the fuel filter even if it's been "checked". If it still does it, get a fuel pressure gauge, and see what the FP is when it's acting up. The FP should be around 10-13 psi; lower at idle or cruise, higher when accelerating.

 

It can change if the bolt holding the distributor gets loose. And since it is easy to do, might as well check, just make sure to disconnect the brown/white(ithink) wire up next to the firewall on the passenger side.

 

The typical newbie thing is to blame every driveability problem on "timing". And of course, if that turns out to be OK (usually does), then it's gotta be the EGR.

Timing won't cause the symptoms at hand. Fuel delivery, either from a confused ECM or from a restricted fuel system, will.

Therefore, the correct thing to do is to leave the timing alone, and actually troubleshoot the problem, instead of yielding to the newbie urge to twiddle the distributor.

Not that it would hurt to check it; but it's highly doubtful that it's off, which means that any fooling around with it is just a waste of time and effort. And even if it is off, it's also doubtful that restoring it to factory specs will make any difference to the problem at hand. In fact, if it happens that it's a couple of degrees advanced, and it's put back to "spec", it might actually run worse.

 

Some basic things for starters are to replace the fuel filter. If its been on there since day one odds are its probably clogged by now. Even after a couple of years theyll get some sediment and crud in them. Also if it persists, get a fuel gauge and see what the pressure is. If the pressure suddenly falls off then the fuel system is under load then youll probably need a new fuel pump. May even want to check the injector filter screens in the tbi itself. Those can become plugged up as well. The CTS itself can be checked using a DVM or a scantool if you have it. Check it with the motor cold and up to operating temp and make sure its within spec. The CTS either has to be nearly open or shorted for an error to be reported on a stock computer. If that doesnt fix then check the ignition system. Ive had similar symptoms from cross-arcing wires that where overloading the module, although the fuel system or possible sensor problems would be the most likely suspect.