jdw1

i just got throught replacing my TPS and it idles at 1500 RPM's but when i pull the throttle it boggs down and wants to die. i noticed the dash pot's rubber bellows are cracked and you can see the spring inside. could this be the problem or the TPS is not adjusted properly? ive tried loosing the TPS screws and turning it both ways and it doesnt help. i cant even drive my truck! do i have to adjust the throttle linkage too?

thook

I'm assuming by the avatar you have a 22re? What year is it? That will be good to know as the TB designs changed from '88-'89.

4Crawler

iTrader: (3)

Test and adjust the TPS is needed:
- http://www.4crawler.com/4x4/CheapTri...#TPSAdjustment

And you can run the DP w/o the bellows, mine vanished years ago. I just spray mine occasionally with some dry silicone lube to keep the plunger from sticking:
- http://www.4crawler.com/4x4/CheapTri....shtml#Dashpot

thook

I've been told by atleast on person that they ran fine WITHOUT the dashpot, even. Even still, the dashpot won't affect throttle advancing....just release and return idle.

abecedarian

By saying "pull the throttle"... if...
- you are saying that you are forcing the throttle plates closed by hand and it starts to stumble and die, then it's possible that the throttle cable needs adjusted, the accelerator pedal is keeping the throttle from closing, or the throttle body itself has deposits keeping the throttle from closing all the way.
- you are saying that you are opening the throttle and it bogs down and dies, you may have a maladjusted TPS, or more likely a vacuum leak or possible leak between the throttle body and air flow meter, or possibly incorrectly adjusted timing.

just noticed you said it idles at 1500... it should be at 750. just a thought... if you've got to get it up to 1500 to idle, your egr may be sticking open, your valves are way out of adjustment or you definitely have a vacuum leak.

thook

Or, the TPS is advanced too far beyond the idle range (producing the excessive idle). That'll affect timing, also. So, yeah.....recheck the TPS.

jdw1

when i took the old tps off and turned the thing inside of it, it would go back to about half way to its original position. i thing its was gummed up. when i done the same thing to the new one it snapped back to its original position real quick. i dont understand the whole ohm reading thing but i guess thats the only way to adjust it. i guess i'll leave it up to my toyota mechanic friend.

thook

You can adjust it by hand and get it right....though, it may take a few tries.

With adjusting screws somewhat loose.....loose enough to turn the sensor body CW and CCW....and the truck running and TPS plugged in, turn the TPS from one end of "stop" to the other until you find the idle setting. The idle will change up and down. You want to turn it just to the point the idle kicks down. That is the idle position and you can then tighten screws down.

It's unlikely that a new TPS will be bad, but it happens. However, if you set it where explained...the low end....that should be good enough for all the all of the other sensor functions to be within range if it is in fact a good unit. Jump the diagnostic terminals TE1 and E1 to check if the ECU is reading the TPS idle circuit and reverts to base timing mode. The idle will kick down. Then, timing can be adjusted if necessary.

abecedarian

the tps has a switch inside that tells the ecu the throttle is closed. it also has a variable resistor that tells the ecu how far open the throttle is so that the computer can control the fuel mixture and such (that's the 'ohms' part).
not exactly a scientific / technically correct way to adjust the TPS, but:
-loosen the screws on the TPS so that you can move the TPS by hand, but it won't move on its own
with the engine at idle/throttle closed:
-rotate the TPS until you hear the idle speed rise. If you don't hear it rise, rotate the TPS the other way until you hear the idle speed drop, then rotate it back til the speed rises.
-rotate it the other way just to the point the idle speed drops and tighten it. You'll have to be very careful here and move it as little as possible.


edit- MATTHEW!!!! GET OUT OF MY HEAD!!!!!

thook

(do-de, do-de....do-de, do-de)

Respectfully submitted for your approval.....

jdw1

when i would turn the tps till the rpm's would go up, it just started idleing erratically up and down, but when i turn the other way it will idle smooth but at 1500 rpm's. and at this point when its its ideling at 1500 rpm's i would push on the pedal and it will bogg down. when i connect the te1 and e1 terminals what am i lookin for? when i do this will the rpms drop instantly? do i have to read the flashing code on the instrument cluster?

abecedarian

you... you... you...
I like bumblebees.

abecedarian

when you get the idle smooth, but at 1500, slowly turn the screw to the left of the throttle body clockwise until the idle reaches the 750 rpm target (+- 25 is okay)
then lets see what happens.

abecedarian

matthew- thinking vacuum leak?

thook

And, butterflies and rainbows, too?

Okay....first off, was it doing this before and that is why you're replacing the TPS? Did you test the original TPS? How does the truck run with the TPS unplugged?

EDIT: Jeezus, Kirk....are you're fingers on speed today?

abecedarian

wow.. I've been served.
but I can type at >70 wpm.

thook

Possibly....or airflow meter. I'd like to know how it runs with the TPS unplugged. That will tell us if/how the TPS is involved.

thook

Carl Lewis fingers, here......

jdw1

i tried adjusting the rpm screw at this point,and it wont drop but to about 1200 rpm's. i know i dont have any vaccum leaks i checked all that. it was running rough before i even changed the tps. before i changed it i changed the plugs, wires, rotor, cap, air fileter, o2 sensor, applied vaccum to the egr which came out fine. and it still would run bad. i would be driving down the road with no power and all of a sudden it would take off. at highway speeds it was fine sometimes. after unplugging the tps it still runs like it did beforehand with no power and sputtering.

jdw1

i checked inside the MAF and it was all clean. the points were clean too.