There is also an amplifier adjustment behind your glovebox for the AC that might need adjusting.

The checkout for the MAF can be found in the '93 FSM sticky'd at the top of this section.

Whatever it is, it does not seem to be uncommon. My freshly rebuilt '93 does the same darn thing. <img src="/forums/images/graemlins/angry.gif" alt="" /> I don't have much history with the truck since we bought it needing a timing chain (and as it turns out a complete overhaul) so I don't know the onset. I do know I replaced a TB gasket for a vacuum leak (wrong shape to the gasket) which of course made a WORLD of difference, but didn't address the underlying issue.

I would try the A/C suggestions, except the only A/C I have is in a box on my garage floor, where I bought it from a junkyard! <img src="/forums/images/graemlins/lol.gif" alt="" />

Oh yeah, and except for idle the truck runs really well with Ted's head, valves and cam.

Have you got in the idea of replacing it? I think it needs a replacement.

You mean, the truck? <img src="/forums/images/graemlins/lol.gif" alt="" />

lol! I have a good laugh there . . .If they have money to replace that . . . <img src="/forums/images/graemlins/lol.gif" alt="" />

Everything on the MAF checked out. I think. The last check per the manual has me checking E1 - Fc with resistance being at infinity. My ohmmeter read 0. Once, I got it to juggle a few numbers, but it quickly went back to 0. I tested, retested, checked and double checked hoping to get SOMEthing, but it's at zero.

Is this right? I'm really not sure. All of the other tests checked out.

That is the output that turns on the circuit opening relay (that sends power to the fuel pump), so as long as that is happening, should not be a problem:
- http://www.4crawler.com/4x4/CheapTricks/AFM/index.shtml#AFMtesting

Thanks Roger

It looks like the MAF is good. I never thought I would complain about a part being good, but this is driving me nuts. I guess I'll take a look at the idle up valve posted above and see what I can see. I don't even know where on the motor this thing is. Ugh.

Jason

Technically, the AFM is not good, since the Fc contact is supposed to open (infinite resistance) when the flap inside is closed. This way the fuel pump is shut off when the engine stops running. But as long as it keeps the fuel pump running, that should be OK.

Idle up valve is on the intake plenum:
- http://www.4crawler.com/4x4/CheapTricks/22RE_Engine_Pix/7.html

You can plug off the A/C idle up valve and see if its your prob.