Got my new MAF, now car idles at 2,000 rpm.

OrangeMustangGt

Founding Member
Mar 7, 2002
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Cape Cod, MA
I need some ideas guys. RIght now i havet he battery disconnected to clear the memory. However, if thats not the problem i have no idea. I put my new MAF in, and as i stated, the car hangs at 3,000 then settles out a 2,000rpm!. I verified the throttle body is fully closed, and i unplugged the IAC with no change.....So i'm thinking VAC leak.....BTW it was not doing this before, but my maf was pegged so i bet thats why it idled normal. I tried pinching off the lines from my manifold, and no help......this is nuts, can anyone give me some tips on how to track this down? Also, i sprayed some electrical cleaner everywhere and no idle changes....!
 
Try resetting the idle again. Here is tutorial.

'94-'95

Begin with a cold vehicle. The idea here is to get the car to a firm cold idle with enough air bleed capacity left in the idle circuit for IAC adjustment.

The idle stop should be set first. Back out the idle stop screw, away from the bell crank arm, until about 1/2 turn past the point where it no longer makes contact (blade fully closed). Using an 0.010" feeler guage, tighten until gauge just drags between screw and bell crank arm. Remove feeler gauge. Tighten screw exactly 1 1/2 turns. If the screw is very loose, put a drop of loc-tite or silicone on it, so it doesn't work out of adjustment.

Now remove the connector to the Idle Air Controller (IAC) just on the other side of the throttle body. Start the car and allow vehicle to warm for 2 minutes. Give a small "blip" to let it settle. If it is having a hard time staying running you may have to get an assistant until you can get to the front of the car. Now open or close the air bleed screw (CCW opens) next to the IAC until the car idles at 575 to 600 rpm. For guys with aftermarket cams and an EEC tuner, you might want to idle a bit more briskly, say 650 to 675.

Obviously, this rpm range is by what the car and driver wants...ie, no set idle speed, whatever works for YOU.

Turn off the car. Now count the number of turns clockwise to close on the idle air bleed screw. If it falls between 1/2 and 2, it's okay, now reverse it out the same number of turns. Log the number somewhere in case you need it for the future. Reconnect the IAC. You are done.

If the air bleed screw is above 2 turns, it's a good idea to tighten the idle stop screw another 1/2 turn, then repeat the idle setting. If it is below 1/2 turn, then loosen the idle stop screw by 1/4 to 1/2 a turn, and repeat the idle setting. Be sure to put another drop of silicone RTV on the stop screw if it was disturbed. Reconnect the IAC. You are done.

Another variation for the 94-95 cars is to reset the idle in the procedure listed above and get the car to idle as low as possible with idle control OFF and the IAC unplugged. (around 600-650 rpms). Then plug the IAC back in, turn off the engine and unhook the negative battery post for 20 minutes. Then hook everything back up and put the desired settings in the PMS for idle control ON. Start with the percentage around 40% in the PMS air bypass setting and work from there. Once you set the desired idle RPM in the PMS, save and start the car. After a minute or two it should be able to control the idle.
 
Yes....That link is what cured mine when I did the swap...Had the same issue...But I could unplug the IAC and things were cool....I ran that way for awhile and then did the full re-set...Not a problem since...
I would expect you'll need to do it with the swap...Its tit to do...
 
sorry, let me clarify. The reason i had to get a new maf was because at all times my old maf would read 5 volts. The car basically wouldent run. So, even at idle the car was reading full throttle fuel mixture, so that must be why the eec adaptive went all crazy and had the idle so high. It wouldent even idle before.

I took it out and wow....did i miss my turbo mustang!!! what a fun car!
 
GreenMustangGt said:
sorry, let me clarify. The reason i had to get a new maf was because at all times my old maf would read 5 volts. The car basically wouldent run. So, even at idle the car was reading full throttle fuel mixture, so that must be why the eec adaptive went all crazy and had the idle so high. It wouldent even idle before.

I took it out and wow....did i miss my turbo mustang!!! what a fun car!
Gocha