I decided to clean my MAF today, and I think I finally fixed the surging idle that kept appering when the truck warms up. I need to drive it more to be sure but its looking promising.

 

how did u clean the maf

 

took the maf off unscrewed the two ends off, and sprayed out the hole with the 2 sensor wires with mass air flow cleaner, then sprayed the rest of the peices clean. pretty simple and hopfully solved my mystery of the bad idle.

 

Only use MAF specific cleaner and do it only when the MAF is completely cold.

 

Must be the earlier D1's were a little different. My MAF does not have any end pieces that screw off. Once the maf is removed from the intake track, there's an open end and a screened end. Inside the housing is a plastic piece with holes in it. Using CRC MAF Cleaner, spray liberally through the holes, most specifically the one facing the screen.

Unfortunatly, there is no way to see/spray the wires directly. Do cold, let sit to dry before reconnecting.

 

No luck must have been cold enough the other night that it didn't warm up enough to affect the idle

 

That sucks Tweak.

 

Tweak - Are you running the 14CUX injection system (original) or has it been modified? even with the erratic idle how does the temp read once it should be warm? is it running cool or warm or middle? Also, have you checked the vacuum advance on the dist. and the IACV or for any leaks around the plenum?

KENK - The main difference between the '94 / '95 MAF and the Gems is the intake air temp sensor used by the GEMS... both 5AM and GEMS are hotwire ensors. Neither MAF has and end that "screws off" per se... however, you can remove the two outer housing pieces by removing the four (per side) TORX fasteners that hold them toether. NO need to do that to clean it though. Just remove the screen and gently spray special MAF cleaner into the air intake hole / port then let the residue rundown and out the bottom. And like Mike said only do this when it is cool.

 

yes it is stock, and yes i just fixed the vac advance and yes I've checked for vac leaks. my only other suspicions are the o2s or possibly the fuel pump gets funny when warmed up, or ecu. oh the temp gauge works fine. it seems like I could run the thing from a cold start for hours no prob, but turn it off and start it back up while warm and the idle just pulses slowly. and the ends with the torx screws is what I was refering to.

 

Maybe try the Fuel rail temp sensor??? If it fails the ECU has no way of knowing the engine is hot at startup and will default to the cold start programming mixture... meaning, it will run rich and cause the O2's to comand the ECU to compensate. Have you tested the output signals from the O2's yet?