89 IROC TBI

I bought the car and it was really hard to start, had to turn over for 10+ seconds 3-4 times - previous owner had taken to pumping gas pedal to start it (pointless on fuel injected motor) well first thing I checked were plugs, besides being coated in oil, they were gapped at 10 thousandths, so I regapped to 45 thousandths and cleaned them and now it is easier to start but still has to be turned over for longer than it should. (15-20 seconds) and when I step on the gas it tries to stall for a second and then I get a surge of power and a hard 1-2 shift (usually chirps tires) and when driving if I accellerate it hesitates/almost stalls and then a surge of power.

Today I bought new plugs, fuel filter and coil, visual inspection of the cap, rotor and wires shows that they are fairly new and in good shape, the car is throwing code 12. What else should I check?

 

Check your fuel filter, might be clogged.

 

replaced fuel filter, coil, air cleaner, breather and pcv valve, deleted A.I.R - runs much better now, but I noticed the right (passenger) side injector is not spraying near as much fuel as the left side, is this normal or do I need a new injector?

 

The injectors should spray a nice even cone of fuel. If there are any irregularities or missing areas, or dribbling, the injector is probably dirty.

As you just purchased the vehicle it may be that it doesn't have the correct injectors in it. F-body's run the same injectors on both bores. Check if there are paint codes on the center stem of the injector. Stock 305's will be green and white. These wear off over time.

If no paint codes then check the numbers on top of the injectors. It will be the longer number (not the 4 digit code). they should both be the same.

RBob.

 

Sounds like a big vacuum leak. Could be a fuel pressure problem also. Long crank times could also be a bad fuel pump relay. When it goes bad you have extended crank times because the oil pressure SWITCH has to see oil pressure
so the ECM will tell the fuel pump to run.

 

most of the vacuum is plugged, only brake, egr, pcv are hooked up. new pcv valve. fuel pump comes on with ign, can hear it, but PO may have put in an autozone fuel pump too... I will check fuel pressure and around the intake for leaks next...

also, tps was off a bit, but I dont think TPS could cause issues this noticeable...

 

What about the MAF sensor? How is the vacuum line going to it? Code 12 comes out every time you enter diagnostic mode because the engine isn't running. The fuel pressure check is a good idea, but you should be getting a code on it if it's going bad (code 54).

 

MAF on a TBI? Where?

 

I ment MAP, sorry! Should be On the edge of the firewall on the passenger side. Has a vacuum line going to it and an electrical connector.

 

I can't find it... does anyone have a picture?

 

Check the picture in the 2nd post of this thread:

https://www.thirdgen.org/forums/tbi/...-bay-pics.html

The MAP sensor is located between the A/C box and the red dip stick handle. It is the small black box with the green connector. At the top of the fire wall on the passenger side.

RBob.

 

It could be on either side of the engine comp. firewall according to the book.
It has a 3 wire connector and a vacuum line going to it. I tried to scan the pic but I installed the wrong program when I installed the new version of windows. Sorry! Maybe some one will have one.

 

thanks guys, I see it now.