I am new to this site so I hope I am posting in the right place. I just bought a 1991 Firebird with a V6, 3.1L. I replaced several sensors that were indicated by the computer. Of the four sensors I changed one still keeps reading, code 35, idle air control valve. I have read some stuff on this site and I am thinking I need to look at the fuel system. I read a lot of suggestions to other people with a similiar issue. Some suggestions were EGR, coolant temp sensor and such. I wasn't sure about coolant temp sensor being problem as no code for it. It seems the fuel system is the way to go. I don't have a lot of money to throw around throwing parts at the car so I figured I would give it a whirl here. My fuel level guage does not work so I am double suspicious of the fuel system. Although the guy I bought the car from insisted that the guage was right because he just filled it up. I put in several gallons of gas in the "full tank" and the guage never moved, always on full. Any comments anyone. I need to save money! Also, forgot to mention something. Cars dies when cold or want to die, restarts and goes ok. After 5 to 10 minutes of driving check engine light comes on only at stop light, when I take off it goes away. This happens everytime I stop. When I check the computer it reads code 35. Is the idle air control valve trying to compensate for fuel issue and the computer thinks it is the IACV?

 

I could be the actual IAC connector causing the problem. If the sensor plug is bad, it wont make contact, and that would cause the computer to throw a code. I dont remember off that what all the voltage reading should be in the plug. I do know that one of them will have 5volts. The computer uses a 5 Volt reference signal for the sensors. Test the plug with a multi-meter.

As for the fuel gauge, if its reading full all the time then the ground for the fuel sender is open. The wire could be broke off or corroded so bad its not making good enough contact.

 

Thanks. I will check that stuff out. It is much appreciated!

 

Did you do the IAC pintle reset and learn procedure?

 

I did the adjustment of the pintle according to the paper that came with the part. It said it should not be greater then 1 1/8 inche from mating surface to tip. I did since posting my question find a website that has "relearn" instructions. I don't know if it is reliable as I have never seen this before. It is a 6 step process for the relearn, as a manual operation it says. I will give the quick run down, see if it seems right.

1 remove batter power for 1 min, restore power, a/c off

2 apply parking brake and block wheels, start engine, shift to drive for automatic

3 run engine till cooling fan cycled once or max of 10 mins on time

4 turn off key for 5 seconds

5 repeat step 2

6 run engine for a least five minutes.

That is the quick of the steps. Sound right? Have not tried it yet. Is there another "manual" procedure for doing this if this is not right or reliable. Thanks.