Ok, I've got a '91 RS w/ 305 TBI that I bought about a week ago. The odometer says 130,000 + but I think the car has a rebuilt engine in it. I cannot prove that but the motor is very tight and runs great.

The problem is that I cannot drive around with my windows down or tops off due to the excessive exhaust stench that comes into the car. When the car is at idle and I rev the engine I get black smoke from the exhaust (not very noticeable but definitely there).

This evening I was working on the cooling system and had the car running and was looking for coolant leaks (air cleaner off and vacuum hose plugged) when I noticed that the fuel from the injectors was collecting on the throttle plates and running down them into the engine in drops. This leads me to believe that the car is running rich plus I get a fuel odor when I shut the engine off. (Not to mention the horrible fuel mileage). I have a feeling that this isn't right so I got on the board and have been searching and reading trying to find a solution to the problem.

My question is: Can anyone tell me in plain english what to do or give me a list of things to try to correct this. I have read about cats begin plugged, O2 sensors being bad, and then read several posts that had lots of abbreviations in them which I had no way of deciphering.

I have a mechanical background and have rebuilt engines before but have never even come close to messing with a fuel-injected car. I have no idea where to start with all of the sensors and such that are scattered around the engine compartment.

I have no idea what the previous owner did or didn't do to the car. Any and all help would be greatly appreciated.

 

i had the same problem - nothing i did helped.

i changed the o2 sensor and CTS. give it a full tuneup and see what that does. i switched to a carb and was romping on the car hard and got the same MPG that i got with tbi

 

Forgive me for sounding stupid but what is a CTS?

 

The CTS is the coolant temperature sensor. It is located on the front of the manifold. Its a brass sensor to the left of the thermostat housing. If the CTS reads colder temp than it actually is it will run rich and never go into closed loop. You problem almost sounds like what was wrong with mine. When my fuel pump was going it ran real rich but also stalled alot and didnt like to run till warm.

 

My car runs great, starts on the first turn of the key and goes like a bat out of hell but smells really really bad.

What if I were to jump the CTS with a jumper wire. That would close the loop and maybe tell me if theres a problem there?

 

If you try this, use resistors instead of a short, like 400 - 100 ohms. I don't like the idea of shorting anything on a computer controlled car

 

could it be the catalytic converter, if it runs good

 

Well, I shorted the CTS and the car freaked. I wouldn't stay running and when it did I got enough black smoke to kill every mosquito in south texas. Won't try that again.

I got a flow master put on it this afternoon and the guy at the muffler shop told me he would put a pipe in the cat for me for $30. He said that no one would ever know if I didn't tell them so that may be my next project.

I picked up an o2 sensor and I'll replace that tomorrow.

 

Let us know how it works. I have the same problem. A fifteen minute ride, and I smell like I've been on an old riding lawnmower for eight hours. My cat and o2 are less than a year old. It's a high flow cat, but I'm thinking it's clogged already.

 

I dont have a cat and my car doesnt smell very bad. Everyone is telling me to get a cat but i wont...just another thing to go wrong

 

Hey I just had an engine put into my car also, ive got the same exact problem, just no black smoke (knock on wood) but it runs rich BIG TIME, and it smells, and the dude who made my engine is clueless.