Falling on its face

[bowshtr]

I had my truck parked out at my ex's house for some time and recently got it home. Well, i started her up and it was runnin like there was bad fuel/ignition prob. Well I drained the fuel out all 2 gallons worth, ran some seafoam through it, put a new fuel filter on it, re-adjusted my air to fuel mixtures, timing etc. Well the truck doesnt seem to want to rev at first. It falls straight on its face and then picks itself back up. I am wondering if you guys think this might be an O2 sensor issue, throttle position, or the AFM acting up. I am going to pull up roger brown's site and do some multimeter testing to see if i cant figure something out. Right now its buggin the living sh*t out of me.

And one other thing that has upset me is the fact that none of my gauges are working...i checked all the fuses and everything looks good. Id like to check trouble codes but i cant without the lights and gauges.

[Sean]

Check the ground on your gauge panel.

I dont see a bad o2 sensor causing that. What kind of motor is this?
It may sound stupid but make sure your air intake is intact and hooked up properly. An opening between the air speed sensor and the intake will give the symptoms you are describing. The sensor thinks you are still at part to no throttle while you suck air through an alternate route and the motor goes super lean.
Could also be a vacuum line. Fouled plugs, cross firing wires ect..

[bowshtr]

Sorry for not giving all the info on the truck...

Its a 22re.

Everything on my intake is secure. I had popped off the intake tube (aftermarket) and cleaned everything out. I sprayed some throttle body cleaner in the TB along with some Mass Air cleaner spray. Nothing really seamed to help. Its just strange that it suddenly did this. It ran just fine when i parked it and periodically started it but after the ex and i broke up and i moved out it sat for 3 months without running. I pulled the cap and rotor and cleaned all the contacts up with some Emory cloth, checked all wires and plugs. Everything seems good. The truck will rev fine with light throttle, but once i apply anything more then light throttle it just falls on its face. I am leaning towards an AFM issue like you said. It does seem to lean out when i punch it and then mixes back out where it should. (I have an air to fuel gauge)

This week i have to put a clutch in my buddies Toyota, so I'm going to take his AFM and put it on mine to see if anything changes. Until then I'm going to see what the multimeter tells me. I have a few printouts from 4crawler as to parameters. If i see some spikes or off voltage either at my TPS or AFM then new parts will be ordered.

I am going to check for vac leaks in the mean time. Its a possibility that some hoses may be leaking somewhere but i doubt thats the issue.

As far as my gauge cluster is concerned, you reminded me as to why its not working. I had cut some wires a while back that would be causeing a ground fault. I got annoyed at the door courtesy switch, since it works as a ground that might be my possible cause.

[bigstelone]

if it picks back up about 2800-3000RPM i would look into a knock sensor. a buddy's truck did the same thing, new knock sensor=completely different truck

[bowshtr]

The problem is for the most part now fixed. I tacked up a new exhaust and figured out it was a backpressure issue. The exhaust i had was creating a horrible scavenging effect causing it to "fall on its face" Who would have thought...

Now shes re-timed and tuned and running good!