No code flashing and still have.........

[rwebb001]

idling issues??

I was having a code 33 for the MAF sensor. It has gone away and not returned (yet anyway). I have new plugs, wires and dist cap. I have checked all over for vacuum leaks and not found any. It seems to get worse as it warms up.

It has great acceleration. It want to die when I stop at a light so I am having to ride the brakes to keep it running. When it dies after being warmed up, sometimes it struggles to turn over (acts like timing is advance too high?).

I have been thru all the basics like trying to figure it out including the TPS calibration.

Any suggestions?

[Hypsi87]

Originally Posted by rwebb001

idling issues??

I was having a code 33 for the MAF sensor. It has gone away and not returned (yet anyway). I have new plugs, wires and dist cap. I have checked all over for vacuum leaks and not found any. It seems to get worse as it warms up.

It has great acceleration. It want to die when I stop at a light so I am having to ride the brakes to keep it running. When it dies after being warmed up, sometimes it struggles to turn over (acts like timing is advance too high?).

I have been thru all the basics like trying to figure it out including the TPS calibration.

Any suggestions?

It's still your MAF. I am assuming that you have an OBD 1 car. The GM MAF's will go out and not set codes and stufff like that.

[rwebb001]

It is an '87 Iroc with 5.7 TPI.

[jonsonton]

Ok I have a $2 dollar(hopefully it will work) fix for you. You just need a can of brake clean.

First make sure the car is completely shut, no key on either. Then unplug the MAF, unscrew the 2 hose clamps, and completely remove the MAF from your car. If you look inside the MAF you will see 1(maybe 2) resistors in there. They should be completely clean. Simply spray them with the brake clean(a couple short burst is sufficient) and let it air dry. Do not try a brush or anything else to clean them, they are very fragile and likely to break.

This MAF is a hot wire sensor. When more air is introduced onto those 1 or 2 resistors it cools them down slightly, in effect, varying the amount of fuel into the combustion chamber. If they are contaminated, the dirt can act like an insulator, not allowing them to cool.

I'm not saying this is a deffinet fix, but it is a cheap guess.

[Hypsi87]

Originally Posted by jonsonton

Ok I have a $2 dollar(hopefully it will work) fix for you. You just need a can of brake clean.

First make sure the car is completely shut, no key on either. Then unplug the MAF, unscrew the 2 hose clamps, and completely remove the MAF from your car. If you look inside the MAF you will see 1(maybe 2) resistors in there. They should be completely clean. Simply spray them with the brake clean(a couple short burst is sufficient) and let it air dry. Do not try a brush or anything else to clean them, they are very fragile and likely to break.

This MAF is a hot wire sensor. When more air is introduced onto those 1 or 2 resistors it cools them down slightly, in effect, varying the amount of fuel into the combustion chamber. If they are contaminated, the dirt can act like an insulator, not allowing them to cool.

I'm not saying this is a deffinet fix, but it is a cheap guess.

yea lets spray some very sensitive wires with brake clean....

NEVER ATTEMPT TO CLEAN YOUR MAF!!!! unless you like to go spend money on them.

[rwebb001]

Jonsonton, have you tried this test before yourself? What if I unplug the MAF and then start the car? If it was a bad sensor, would it not react differently right off?

Also, this car doesn't have the air box attached. How does this impact the operation of the MAF? I hooked up a single element filter to the MAF for testing but didn't seem to help out. I don't know if I didn't let it run long enough or what.

[jonsonton]

Originally Posted by rwebb001

Jonsonton, have you tried this test before yourself? What if I unplug the MAF and then start the car? If it was a bad sensor, would it not react differently right off?

Also, this car doesn't have the air box attached. How does this impact the operation of the MAF? I hooked up a single element filter to the MAF for testing but didn't seem to help out. I don't know if I didn't let it run long enough or what.

Yes I have tried this myself. I got lucky, because this was the problem in my case.If you did unplug the MAF and started the car(and the MAF was at fault) there would be a slight to substantial difference. I wouldn't recomend this though, the ECM will sense an open in the MAF sensor and will trip the MIL. If however you did do this, after your drive you could unplug the battery for about 10 minutes to reset the computer.

When you say, a single element filter, are you reffering to a K&N cone type filter. If so, this should not effect the system that much.

[rwebb001]

Yes, it was a cone type filter. I wasn't sure if the filter restriction had much bearing on the MAF operation.

I already did the test of unplugging the MAF but I have since then reset the computer. I will try out your test and see what happens. Thanks!