Let me explain my surging
It idles fine
I can even apply a small amount of throttle
At a certain very small point, if I increase the throttle slowly, it begins to cut out intermitntly, after a certain RPM ( I dont have a tach to know that point)
Like as if I was tapping the gas, over and over,
but i'm holding the throttle steady.

Went to town, topped off the radiator, pulled the Throttle body, checked the ports-got H2O flow- checked the hoses, blew through them- got H20 flow
reassembled, clamped hoses tight
Still surges

Could it be the sensor on the thermostat housing?
Can i test that?
What else could it be? <img src="/forums/images/graemlins/confused.gif" alt="" /> <img src="/forums/images/graemlins/confused.gif" alt="" />

i've been searching posts and reading for several hours now,
I can't seem to find anything similar to my issue.
Plenty of "idle surging"
Had that problem last summer

Looking at the troubleshooting from the FSM I can't find a
"surging during acceleration" either.

Anyone have any suggestions?
<img src="/forums/images/graemlins/confused.gif" alt="" />
<img src="/forums/images/graemlins/confused.gif" alt="" />

You might want to double check the TPS, paying close attention to the slode to open throttle resistance (VTA-E2) looking for any dropouts:
http://www.4crawler.com/4x4/CheapTricks/TPS/index.shtml#TPSAdjustment

Ideally you should see the resistance increase smoothly from say 500 ohms to 5000 ohms as the throttle is opened.

Just did adjust the TPS
Was pretty thorough too.
Did the progressive check and the jumper check once installed, both OK

I'll pull it tomorrow, clean, reset/check
and/or
try another TPS I had pick n pulled.

Thing is when I re installed the 1st replacement TPS (the one currently installed) the surging problem was still happening at first, sort of gave up on the problem, cleaned up the tools, went to move the truck and the surging acceleration was cleared up, So i've been driving it since.

I live out in the country, get in the truck n drive.
It warms up on the road and it seems the last time I felt the momentary cut-out with steady pedal, was right as the thermostat opened. If that helps any.
I'm gonna pull the term tomorrow and see if anything changes.

I'm going to check the resistance of the water temp sensor.

If these don't work, I'm stumped. If they do work I'm still stumped as to WHY????

STUMPED!!!!

TPS is set just fine and fully functional
VTA-E2 from .64 to 4.7 gradually while opening throttle
Infintity @ .85mm

AFM to be tested next I suppose

Any long shot guesses? <img src="/forums/images/graemlins/angry.gif" alt="" /> <img src="/forums/images/graemlins/confused.gif" alt="" /> <img src="/forums/images/graemlins/scared.gif" alt="" />

Maybe the EGR valve/modulator/BVSV is acting up? Mybe try plugging the vacuum line to the EGR and see if anything changes. The BVSV opens once the engine warms up to start the EGR modulator working.

It doesn't seem to be a warm cold issue, even though some of my theorys may point that direction.

I started her this morning before I removed the TPS,
At ambient temperature.
Starts right up and idles fine
and more than a little throttle and it surges
So I held the linkage steady at surge and let it warm up while surging

Never noted a change through out the warm up

25miles back to town I go-EGR and AFM next
I'll stop in the library to check for any new ideas.
THANKS!!!! <img src="/forums/images/graemlins/kewl.gif" alt="" />

<img src="/forums/images/graemlins/zombie.gif" alt="" />
Long day
AFM tests AOK. All tolerences are there. I thought it may be faulty as I checked the e2-vs range from closed to open.
As I opened the flap slowly the number increased to a point then decreased back down, almost jumpy erratic readings.
Went to pick n pull and test three others, they all act like that so...
I'm ruling out AFM
EGR has vacume, so I gave it a few love taps while it was running, idle and in throttle surge got no change in any thing evenwhen blocking the vacuume hose.

Been holding the throttle from the engbay alot today just listening to it surge, there were a few times it would "catch" andthe throttle would catch up and begin to accellerate and then it would slip right back to
surge, surge, surge

I can drive it but I have to use as little as possible throttle and chatter the gears to go at all. Once the engine hits that certain RPM its cut out time.

Havent seen a prob yall on the board cant get to the bottom of. To me the stealership <img src="/forums/images/graemlins/angry.gif" alt="" /> or any other mechanic <img src="/forums/images/graemlins/cyclops.gif" alt="" /> is really out of the question cuz the compendium of toy knowledge really sits here IMHO.

<img src="/forums/images/graemlins/scared.gif" alt="" />I'd really hate to post over at Pirate cuz I'd have to re register and start newbie and probably get sent right back over here <img src="/forums/images/graemlins/scared.gif" alt="" />

So who's got the next suggestion <img src="/forums/images/graemlins/confused.gif" alt="" />

Any other stellar Toy mechanics BB's to post at?

Would an air pocket cause this problem?

Where would it lodge itself to cause the problem?

Had it parked, back end in a ditch to lift the front and let the coolant run through. Gave it a few good rocks jumpin on the bumper.
Would that be sufficient?

Only if you were hot. A cold or semi warm start may not be enough, especially if the pocket has been stuborn. (And make sure you take off the radiator cap too)

I had a very similiar problem to your surging about a year ago. Only my pickup surged only at idle because there was too much coolant in the radiator, and the idle speed was not enough to turn the water pump.
Keep diagnosing, don't get too frustrated! <img src="/forums/images/graemlins/cheers.gif" alt="" />