Pulsating Idle

[tjh]

Either not on tight or leaking (hard to check without a cap tester though.

I just made a google ! that's a pricey little gadget .

[SilverBullet75]

Couple other checks:
- Intake Manifold gasket
- Make sure all electrical connectors are plugged in tightly.
......I know it sounds elementary, but when working in the engine comp., things can bump loose. (Speaking from experience)

- Check for Nervous Leg-bounce. Can cause Idle fluctuations.

Can't think of anything else off hand.... anyone else?

[Triathlete]

I just made a google ! that's a pricey little gadget .

The cap or the tester?
If the tester...ours get tested as part of our required emissions tests.

[tjh]

The cap or the tester?
If the tester...ours get tested as part of our required emissions tests.

The fuel cap of-course $36.23 that's outrageous .

Heck the tester is only like $2391.99 , I mean that's like couch change .

A required test ? ha doesn't exist here !

[tjh]

I sprayed carb cleaner all around the intake/throttle body , no increase in idle.


High Idle returned to day . When the motor started the high idle I popped open the hood, and grabbed the shaft that the accelerator cable is attached to . I was going to increase the throttle , but the weight of my hand on the shaft caused the idle to return to normal. There was no discernible downward movement of the shaft. I increased the throttle and it returned to high idle, and then I pushed down on the shaft and Idle went back to normal. I cant detect any downward movement of the shaft .
What is going on ? How do I fix it ?

I still get pulsating idle when in gear . When I engage a gear the Idle will drop to about 500 rpm and then return to 750 most of the time . Other times it will just bounce from 500 to 1000 rpm ,over and over and over.

[tjh]

During a high idle episode , I pulled the plug on the TPS while the engine was running,and the idle immediately returned to normal.

Could the TPS be the culprit?

[Grif]

During a high idle episode , I pulled the plug on the TPS while the engine was running,and the idle immediately returned to normal.

Could the TPS be the culprit?

I would say quite possible yes. I replaced mine when I was having idle issues, easy to do and a cheap available part, so its an easy enough test.