84dreamyoda

Here is a video of the problem I am having. If I try to hold my gas pedal around 2k RPM while in neutral and parked in the driveway this is what happens. I havent tried it in other gears yet, also I notice if I am driving and try to give it soem speed gas to get going their seems like a bogging down area but it clears up after a few seconds. Doesn't matter if warm or cold. I have done tps testing with ohm reader and it seems to be fine in those test. I followed http://www.4crawler.com/4x4/CheapTricks/TPS/index.shtml for the test. Could it still be bad, could it be the AFM ( I haven't checked it yet). I have deleted my EGR last year with block off plates and have most of my vacuum lines blocked off so I don't think its a vacuum issue but maybe I have the vacuum lines hooked up wrong?

edit* Forgot to mention that when I disconnect the TPS it does not do this anymore.

Co_94_PU

iTrader: (-1)

Looks like either a cutoff triggering or more likely a failure in the VAFM.

Test the VAFM resistance while manually manipulating the flapper.

Verify the TPS idle signal is reaching the computer.

Punchy

Use a analog ohm meter and ohm out the TPS and AFM, Look for dead spots as you slowly actuate them.

Co_94_PU

iTrader: (-1)

Vafm is a resistor ladder. It can have dead sections.
Tps, is a linear resistorIf you wear a dead spot in a tps you either loose vcc completely or the low range throttle angle (wiper rotates clockwise against the board)

84dreamyoda

Crazy, I had my GF move the throttle slowly while I checked the TPS via VTA-E2 resistance and it seems pretty steady and didnt notice anything strange. I'll check the VAFM next and see what I get.

Co_94_PU

iTrader: (-1)

idle not throttle angle, if the CPU has an idle signal it will trigger a cut off above ~1200 RPM.

If you find good signal from the TPS and VAFM, check the Igf next.

Terrys87

iTrader: (1)

I have had some bad AFMs that never thru a code but when doing a resistance check you could tell right away it was bad. I could also swap in a known good AFM and see the difference in how the truck run. The only time I ever got a code for the AFM is if I left the cable disconnected. Check to see if the flapper moves freely inside as well.

As far as the TPS, I could get them to pass test but in my opinion, they eventually just wear out. Sometimes cleaning the contacts can get some more life back into them but a truck with hundreds of thousands of miles, the TPS will have millions of cycles of operation on them and I think there is only so much you can do to get more life out of them. The TPS is on part that I will replace on an EFI motor if I suspect it is original and giving problems.

Boostincx

I literally just had the same problem, replaced TPS, fuel filter, cap ,rotor, plugs, wires... still no fix. I was throwing 2 codes both led to bad afm, I just didn't realize it cause my check engine bulb was burned out lol. Ordered a $65 used toyota AFM off ebay and bam problem fixed. Of course 3 miles down the road I get the dreaded code 52, it's always something.