I just bought a 91 RS with tbi. The person I bought it from had some vaccuum lines missing and disconnected. Because of this I have a vaccuum leak that I havent been able to trace.

The car runs great at idle and in P/N but in gear it will bog out after 2000 rpm. It is either getting fuel from the injectors and the throttle blades are not opening or just the opposite, all air no gas.

I dont have anyone close to my home to give me a second set of eyes otherwise I could tell which it is doing. but I would still like some feedback on what the problem could be. I havent had much time to look at it but the thing is frustrating me. I just want to find out what things would be the first to look at. thanks for any help you can give.

 

let it idle leave the air cleaner on take a can of carb cleaner and spray it arround the intake. When you hear the engine bog you are in the area of the vacum leak. Then I usually use a piece of brake line held to my ear to listen for the whislte and pinpoint the leak.
If it turns out you have no vacume leak the same symptoms you have descriped can be from a weak coil or incorrect timing.
As far as a second set of eyes goes you can work the throttle while under the hood by hand. I doubt you would find anyone to sit in the engine compartment while you drive arround trying to stall@2,000rpm anyway.

 

I had a similiar problem with mine. Would climb through the RPM range no problem while in park but under load was bogging above 3,000. Replaced Cat, and O2 sensor, ran great. I still am not quite sure why it would flow well enough when not driving, logically you would think that the airflow if restricted would be restricted all the time. Just a thought!

 

okay guys,

I have done a full tune up, checked the cat, injectors and throttle linkage. the drivability came back a little when I did the tune up. now instead of falling flat at 2000 rpm, it will accelerate thru the entire rpm band but will still stumble badly when I open the throttle about half way or more.

I am also smelling a burnt plastic smell from the plastic box that is piped to the smog pump.

I have not gotten to the O2 sensor yet but if that doesnt do it what else will?