Need your help guys.

Checked in past threads but could not find a solution for an idle needle that keeps bouncing between 1500 and 200 rpm - the ISV is new so that's already covered. Anything else I should clean or remove and replace??

Its a tip so keeping the idle high enough so she does not stall in D is a major issue.

Many thanks!!

 

That was a sign of a bad O2 sensor on other cars. I think you can pull the plug and see if the idle smoothes out. There are four sensors, so I would bet that it is not the problem and you would expect a CEL. However, you could pull them one at a time and see if it makes a difference.

 

why is the idle speed control new? is it because the rpm was already bouncing?
what is your airbox setup?
did you check the mass air flow meter?
do you recall changing the fuel filter?
your problem is not electrical
what year model is your tiptronic?

 

Many thanks guys - the problem seems to have disappeared on my next drive following this post. She is now at 780 rpm but steady. I had changed the ISV as good measure instead of cleaning & replacing. The airbox is standard with the turbo spout curved upwards for cooler air. The fuel filter was replaced during the last service a year ago. Its a sept '95 tip.
Could the problem have occurred only for that one drive because she cranked on a very weak battery??

 

Another quick question which does not seem to have a firm answer perhaps. Should I change the tip transmission oil? She has run less than 8000 miles in 11 odd years and there are no issues with gear changes in D or in tip mode. There is a slight clunk when you engage first in tip mode at very low speeds ( less than 5 mph ) but other than that, all fine. I think the workshop manual recommends fluid change after 8 years.
Many thanks.

 

780 rpm with gear engaged, 840 rpm in neutral, thats the exact measures.
No, a weak battery wont change your rpm. when car starts, you could even disconnect the battery and the car will run, the alternator can even light up the cabin custods, and a few minor things.
A tiptronic should have oil changed every 20000 kilometers/and or 2 yrs. and the tiptronic filter changed, regardless what the manual says.
The knock you have in first is not from the tranny but from the differential.
Change the oil in the tranny with the $50 ish filter and rubber seal, and change the differential oil 75W-90 (0.9liters/1 quart), and you will have knocks no more.

How much did you pay for the ISV?

 

I really do wonder what it was!
I will also definitely be changing the tranny & differential oil. Thanks
The ISV was about $160 in Dubai if I remember correctly.

 

ISV typically get filled with internal junk. A quick clean is normally all that is needed.

Where ever you bought the new one should give you the old one back. Then go to www.p-car.com for a DIY for cleaning.

Next time ask before buying?? Wouild have saved you money.

 

Will do Jean-Peirre, thanks!
BTW, do you know of a quick fix for the front hood latch? My one does not seem to close and keeps popping back up. Any adjustments to the claw possible?

 

Humm.... good question. I will check my manuals. Meanwhile, if any of the real GURUs care to step up to the plate??

 

Sometimes it is just somthing obstructing the hood.
I will be willing to buy the old ISV from you if you still have it.
I have used brake cleaner to clean mine and it is not working properly.
I have to dismantle it every now and then and spray some WD40

 

IIRC when the idle was erratic on my tip cab it turned out to be the fuel regulator....it also made the car difficult to restart after a few hours of being turned off but had no problem starting if the car had been sitting for a while.

 

is your hood release handle returning fully after you pull it?
mine is not and it makes the hood hard to close.
i just need to remember to manually push the handle back in after pulling.
jeff