FZJ80 idling high and not going into lockup (1 Viewer)

[nieboo]

Hi guys,

I have a weird problem and I would like to get your opinion if you would not mind. Intermittent problem where the engine goes into high idle while driving (between 1200 and 1600 RPM when shifting to Neutral when rolling) and then does not go into lockup anymore in any gear. I then end up with 2400 RPM at 110 kph. I have not noticed any pattern, except for the fact that it usually happens when the engine is warm and/or after doing a long stretch uphill out of lockup. The shop said there are no recorded faults, but I don't have a lot of faith in that since they also thought there was no ECU for the AT...

If you have any (subtantial) suspicion on where I should check first, please let me know. Before I start on a wild goose chase. I appreciate it.

Cheers,
Niels

 

[elhombre]

I would check the Throttle Cable which goes between the throttle body to the side of the transmission. If this cable is worn and does not slide freely, it may be holding the throttle open and/or not telling the transmission the correct throttle position. The transmission would not know how much foot you are putting into the engine so it doesn't know when to shift.

I would put a piece of tape on one of the nuts where the cable is attached to the bracket at the throttle body. This way, when you take it off, the taped nut will hold the adjustment for when you put it back together. Second, I would disconnect the throttle cable from the transmission. Make sure the cable moves smoothly through it's casing. It's a no-cost place to start.

 

[Michael Hanson]

Throttle cable and Id also replace the trasmission cable,oh what a difference it makes. Mike

 

[nieboo]

Thanks, 2x throttlecable. Righto. I'll go and check tomorrow.

I was thinking it might be a temp problem - driving to work this afternoon it happened again after going uphill and did not correct till I got to work. Outside temp was about 10 degr higher than when I drove back home this evening: no problem, except for the last stretch uphill, where it happened as well, but it corrected quite fast after reaching the top. Could the MAF sensor be broken ? It has a temp compensation, correct ? I cannot measure the values over the contacts, because the manual has a 7-pin plug and I have a 5-pin plug on the car, so the values don't match. Any thoughts ?

Thanks anyway,
Niels

 

[elhombre]

When I had the MAF not work, it was obvious and the car barely ran with a code (PO100 if I remember right). Personally never have heard of a MAF "sort of"working. When the transmission computer throws a code, it usually causes the OD light to blink and/or Check Engine light come on.

 

[nieboo]

Ok, I checked the cables today and they seem to be running fine, no catch and no rubbing. Condition is really good, both under hood and at gearbox. I am going to take it back to a different shop to hook it up to the OBD. I'll let you know, but thanks anyway.

Niels

 

[reraub]

I had the same problem, my throttle pos. sensor was out of wack.

 

[nieboo]

Allright, thanks. I'll go and check. maybe I can diagnose with volt/ohm meter - did it throw a code ?

 

[coax]

Should also check the hose from the air filter box to the throttle body; they get old, crack, and let unmetered air in.

 

[80t0ylc]

I believe the "O/D Off" light on your dash will flash on & off if your AT ECU has thrown a code.

 

[nieboo]

I checked the throttle position sensor with a ohmmeter in acc with the manual, and it turns out the IDL-E2 contact for closed position is outside parameters (28 ohm in stead of 2.3 or less). At this point I don't know if I should try and clean it if possible, or order a new one right away - I will probably go for the latter. Any ideas welcome.

Thanks for the inputs.

Niels