my car's run great ever since i got the gal back in january... now all of a suddon with the warmer weather coming (perhaps that had an influence on it?), the car gets approx 2 MPG of 50/50 town / highway driving. i'd say it's a tad low if you ask me

i started having issues after my car would warm up after 10 mins of driving, the check engine light would come on.


my car has extreme lag off the line and driving. feels like its going to bog down and stall if i go from a cruise to try to accel a bit more without the tranny downshifting. starting up it puffs out hazy dark smoke and then clears up. smoke is confirmed to be fuel, smells like unburnt gasoline (quite strongly might i add). under WOT extreme smoke screen.

• the problem is, it's running EXTREMELY rich and my check engine light has come up. where should i start to diagnose this and how can i get my car running in top shape with the fuel mix ratio optimal?

engine is a 1991 305 TPI (LB9) with 91,000 miles

carmine

 

I'd start with the coolant temp sensor, oxygen sensor, and the injectors. A faulty cts, or o2 sensor can cause bad gas mileage. But as rich as yours seems to be running, you might even have some clogged or malfunctioning fuel injectors. Those two sensors are fairly cheap to replace. As far as the injectors go, try some concentrated injector cleaner. I usually use two bottles in a half tank of gas to get it good and strong. Get an ohm meter and check the resistance of your injectors to make sure the coils are ok. They should be between 13-16 ohms. Any lower than that, they're bad. Oh yeah, the very first thing you should do is find out what code is setting off your check engine light. Figuring out which code is coming up should at least point you in the right direction towards fixing the problem.

 

i guess that give me a good place to start diagnosing this. i really hope it isnt my injectors on their last leg. i'll run the concentrated fuel injector cleaner through and see if it makes any difference. if not, i'll see if i can take the car somewhere or find someone in NNJ with a unit that'll tell me what code is coming up. if its related to the o2 sensor or anything else in line or the cts, i'll work from there... i'll post what happens when i can get around to it.

thanks

carmine

 

Actually, you don't need to pay anyone to figure out what code is coming up. All you need is a paper clip to jump the A and B terminals of the ALDL port underneath the dash on the driver's side. The A and B terminals are located in the upper right hand corner of the connector right next to each other. Jump these two terminals with the paper clip, then turn the ignition on. Don't start it, just turn it on. Your check engine light will flash once, then twice at first. This is code 12, which just tells you the ecm is in diagnostic mode. After the code 12 flashes, the trouble code, or codes will flash next. Example: If it flashes 3 times, pauses, then flashes 2 more times, that would be code 32. So dig up a paper clip, figure out your trouble code, and take it from there. There's a writeup in the tech articles section here on the site that describes in detail how to retrieve the trouble codes from the ecm. You might want to print that off and have it with you when you go to check them. You'll need a Chilton or Haynes repair manual to tell you what trouble codes you have according to their number.