Calmchaos

Hello,
I get a misfire at above 3K Rpm, but I don't seem to get it when I put my foot to the floor.
I assume this points to the AFM, because if I remember correctly, the AFM is not taken into consideration when at WOT. But I am not totally sure where I should look first.

Any ideas appreciated.
Thank you!
-Brett

Calmchaos

^^bump^^

xsboost90

pull the black cover off the afm and check the sweep to see if the contacts are corroded etc... Also make sure the flapper door inside moves freely. If these both look ok you may look at your dist. cap, rotor and plug wires.

Calmchaos

Took the cover off and it all looks pretty good in there. And the flapper door moves freely with no noise all the way.

Tom M'Guinn

Check the resistance of the AFM (and TPS) with a multimeter as you open the door, looking for a clean progressive sweep. www.clarks-garage.com has the test procedure I believe.

Calmchaos

AFM tested. It passed the clean sweep test, but the temperature sensor seems to be reading about 1/2 of what it should be.
I don't know if that would cause the problem.
Didn't test the TPS, but I will tomorrow. It's only a year old, but I'll test it later anyway. It still makes a nice clean click.

Calmchaos

Since the AFM temp sensor was reading a little low and probably causing a lean mixture, I turned the AFM trim screw in a little bit and it helped the misfire.
It is a lot better now, but the misfire isn't completely gone. I'll take the screw in a bit more and see if it gets rid of the miss completely.