Good evening ladies and gents I am new to the third gen scene. I have just purchased a 92 RS 305 TBI 5speed car and am having some trouble with it. The person I bought it from said last he drove it it had an overheating problem. But looking at the oil, cap and things like that no indication of a blown head gasket. The radiator is busted though. But in an case he said it was barely running, misfiring and what not. I have been able to get the car started but it is doin exactly what he said not wanting to run. I have to hold my foot to the floor to even get it to start and when it does start it will not go past 2k. That is to the floor. Also when it is running it is pouring out black smoke. Changed the plugs and all 8 were black and gas fouled. Now here is the crazy part when I unplug one injector it will idle but I can't give it any gas as it will cut off. My guess is a bad ecm or throttle body. The previos owner had a new fuel pump installed in 2002. The car has been sitting dormant since 9/02. This monstor is ready to be unleashed and I just need some advise to do so. By the way it has just 127k on the clock. Any info will be appreciated.

 

From what you described that almost sounds like a bad catalytic converter.

 

Wecome to "the scene"! And hello fellow North Carilonian! I used to live in Greensboro, Winston, and Kernersville - now live in Cary.

Sorry I'm no expert on your problem - I'm alot better at turning wrenches than diagnosing - especially with the computer controlled cars - but plenty of folks here will give you a place to start.

I can however point you to a local club for you to check as well, Triad F-body Club - that will give you some local contacts, and maybe someone there can actually come take a look at your car with you.

Again, welcome aboard.

 

doesnt TBI just have one injector to begin with? did you pull the primary or cold start injector (dont even know if TBI's have cold start injector...)

 

TBIs have two injectors.

A misfire problem can usually be traced to the basics. Replace plugs, wires, cap and rotor (I'm sure it needs it anyway). If it still misfires you may have a bad coil or ignition control module.

While you're at it, replace the air filter and fuel filter. You'd be surprised how much of a misfire a clogged fuel filter can create, especially under load

My guess is that the plug wires, cap or rotor (maybe coil/icm) are bad/old and it's getting spark at the wrong time, or no spark at all. So when you floor it to keep it running all the gas is dumping in the cylinders and igniting at the wrong time/not at all causing it to run rich and foul the plugs, misfire and not rev and also causing the black smoke out of the tail pipes.

Do like I say with the plugs/wires/cap/rotor and it'll probably run a ton better. Just get AC Delco brand stock replacement parts, no need to go fancy.

 

Alright I'll try that. Had it in mind to do anyway. Also I'm gonna cut the exhaust at the cat and put new pipe from front to back. FLOWMASTER wonderful deep sound. As far as the NC person thanks for the advise on the club here in nc. I'll give that a try as well. Keep the advise comin as I am kinda stumped on this problem.

 

Could it be a bad O2 sensor? My TPI did the same exact thing, O2 voltage read correctly, but had the same symptoms. Replaced the O2 sensor and all was fixed.
Another time, I would experience a problem with it pouring black smoke and generally running terrible.... so I datalogged it and noticed many of the values seemed to be doubled. That time the ecm was bad.

 

IS the computer giving you any fault codes?

 

no there is no codes being thrown. The previous owner had installed a new o2 probably a month before he quit drivin it in 03. Do you guys think I should replace it anyway. My friend that has several 3rd gens said the same thing about the o2. Also he said somethin about the coolant temp sensor. So it is kinda a guessin game. I keep you informed. Thanks for the info so far.

 

If any of what you are saying "could" be wrong, the computer would identify these problems by displaying a code. The codes come on the dash as a series of flashes. Do a search and you will find how to read these codes if you do not already. You will then match up the code or codes to a list of what these are and it should tell you what is at fault.

 

Check your firing order as well too when you replace the wires. Could have a few crossed wires, which means unburned fuel is fouling out the plugs.

Good luck with it, these cars are VERY addicting!!

 

Just to let everyone know after changing the plugs AGAIN, cap and rotor button, and ignition module it still done the same thing !!!!

I cut the converter off after a hour of cussin and guess what

it purred like a kitten. It filled the shop up with black smoke but after it ran for 5 mins it cleared up and now its all well. Guys for all the information and if I need anything else I'll let you guys know.

 

Congrats