Pulled codes

2 and 7

2-AFM signal
Re ttested the AFM everything looks tolerable, went back to pick n pull and tested an 87 AFM same range as mine

7- Throttle position sensor signal
pulled the throttle body yesterday and she is working good. Smooth operation and a good increase on the meter as I open the throttle slowly.Plus all the right settings.

Both lean toward the unit, the circut or the ECU

So where should I go now?

Okay went through those diagnostics and every thing checks out

It's not the charcoal canister either

But check this out
Okay truck idles smooth, unplug the TPS, still smooth, throttle and it surges syatematicly over n over

Same thing keep but the TPS plugged in, EXACT SAME malfunction.
Unplug it while holding steady throttle, no change.

It is set correctly and the idle drops when using the diagnostic plug.

How does YOUR Toy react at a light steady throttle then unplug the TPS?

Gonaa do some wire checks. Pulled the cpu and did the flow chart thingy, seemed okay from there.

It's not the EFI relay or the CIRCUT OPENING relay, ohm'd those out too.

ANyone??

Got this going over at PBB too

Surging woes at Pirate

if ya pull the tps it should raise rpms it sends the ecu into a limp home mode not a very accurate way to diganose after all these arent GM's (bad joke)have you simply checked your idle speed if thats ok you may have a dead spot in the tps or maybe need to burp the cooling system

just curious what is your idle speed? I had similar problem and it turned out to be of all things that the idle speed was to high. I can't remember how it was explained but the fuel injectors have some type of cut off in the Gen 1 yota's.

Here is the scoop on the surging idle w/ brakes problem:
- http://www.4crawler.com/4x4/TLCA_TruckTech/TruckTech.04.09.html

Decided to drive it home thirty miles. I get 6 mph in 1st, 13 in 2nd, 24 in 3rd, 35 in 4th and then it begins to cut out so I had a lot of time to play with the throttle all the way home. What i did notice after a while was I could gas it harder at really low rpms to give it a little extra boost during my snail crawl, So to me, that ruled out the TPS problem, it was responding. After a few times of doing that it cleared up. Runs great again!

wish I could remember K.I.S.S.
Keep it simple STUPID

I'm gonna put my money on a bad fuel filter (she did sit for6months)

Gassing it hard probably cleared it up.
Sounds right to me.

Just enough pressure to idle but with too much throttle, it would starve the engine, then build quickly and starve and on and on.
BUT I'll never know, unless it happens again, then I'll swap a fuel filter (I"ll have on hand) and go from there.
THANKS TO ALL WHO TOOK THE TIME TO THINK WITH ME!!!!
<img src="/forums/images/graemlins/drunk.gif" alt="" /> <img src="/forums/images/graemlins/cheers.gif" alt="" /> <img src="/forums/images/graemlins/kewl.gif" alt="" />
Now back to my sound insulation and diesel-vs-Ethanol conversion projects
<img src="/forums/images/graemlins/smile.gif" alt="" />

IT's not the fuel filter
Dang it!!! <img src="/forums/images/graemlins/angry.gif" alt="" />

Started yesterday again so Ipulled over in all confidence that a fresh filter would correct the problem and
Nothing changed
So I went to pick n pull to pull for an AFM
have to wait till 2morrow to install
truck is 50 miles away <img src="/forums/images/graemlins/frown.gif" alt="" />

Might want to check out the cooling system purge again ...
... Heater on, front end on stands, radiator cap off ...
... Same problem with my truck as you noted on my post ...
... never though I'd see myself jumping on a bumper trying to burp a Toyota but if that's what it takes ... <img src="/forums/images/graemlins/rolleyes.gif" alt="" />

could it be the TPS cable? I just bumped mine, investigating other problems, and the harness will not stay connected properly, I haven't dug into it, but I think I have lose wire conections. I am also thinking for you and me, nasty injectors.