idles high.. sometimes.

[elwesso]

I first noticed this a few days before I raced the Q about 2 weeks ago...

What happens is the car will seemingly randomly idle at 1500 RPM in park or neutral.. Sometimes if I rev the car a little bit (say to 3000 RPM) it will go back down to normal... Other times it wont... It idles smooth, just high... Idle doesnt fluctuate, stays steady right at 1500 and would probably idle that way for a while if you left it......

It only does it after the car is fully warmed up. My work commute is only a couple miles so the car rarely gets fully warmed up (much to my dismay , i hate short trips in the Q, seems like a waste)....

It doesnt ALWAYS do it, and it doesnt seem to matter if the AC is on. It did it again today (I drove for 10 miles or so)..... I unplugged the IAC and the idle went down to about 1100 but went right back up as soon as I plugged the IAC back in... I cant always replicate the problem... however it seems to always have a correlation for when the car is run hard...

It did it almost every time after each run when I raced 2 weeks ago. If I turn the car off and restart it will often idle normally... Obviously no ECU or trans codes...

The only thing I can think of is that the IAC is stuck slightly... i took it off late last year and cleaned it really good to sparkling... It wasnt that dirty when I took it off... I cant think of anything else that it could possibly be...

[ahardb0dy]

I noticed last night on our 94Q after replacing the fuel pump that the engine is idling high, when in park it is idling at about 1,100, in drive it's about 700, what is the idle supposed to be ?

This weekend when I do the knock sensors I will clean the IAC valve and see what happens, I already removed the TB and cleaned it real good a few weeks ago when I replaced the plugs.

[Aussie Q45a]

Had the same problem Wes, maybe it was just a fluke but I sprayed WD40 down the inner accelerator cable and worked the pedal a few times. I think that I should have puffed Graphite powder instead, as that wont attract dirt. Maybe if it happens again I'll use brake cleaner first then the Graphite.Cheers

[Q45tech]

Common to find throttle cables adjusted too tight........should be 1/3 -1/4 inch of vertical slack.

Make sure the coolant is flowing thru TB as the hot wax fast idle control sometimes gets bypassed.

[elwesso]

Had the same problem Wes, maybe it was just a fluke but I sprayed WD40 down the inner accelerator cable and worked the pedal a few times. I think that I should have puffed Graphite powder instead, as that wont attract dirt. Maybe if it happens again I'll use brake cleaner first then the Graphite.Cheers

THanks ill give that a try...

Tech i thought about that but it seems as if i have enough vertical play, ill check it again. Thanks.

[elwesso]

Just to let everyone know, thats what the problem was.. it idled high at a gas station today, i took the throttle cable out of the litlte holder and it idled down perfect...

[Aussie Q45a]

Just to let everyone know, thats what the problem was.. it idled high at a gas station today, i took the throttle cable out of the litlte holder and it idled down perfect...

So was the cable sticking or too tight??????

[elwesso]

seems as if it was too tight.....

Im going to adjust it tomorrow and tighten it up... Im going to put the gas all the way to the floor and adjust it with 1/4 inch of a free play or so... and then let it back down and recheck.....

[fourdrinie]

hey wes, has this been the high idle problem you have been battling for some time? it would be great if you finally got it fixed...keep us advised!

[elwesso]

So far the car is idling much lower than it ever has... Its been idling at 650 all day, however thats with the AC on... Im going to be driving some more this afternoon, so I'll leave the AC off and see what happens...

[Meaux]

So how did the WOT adjustment pan out?

Did you have to re-adjust the cable @ closed throttle?

Just curious...

[elwesso]

What i did was wedge a golf club and put the seat up to keep the accel pressed down all the way.. I then undid the cable from the bracket, held the throttle WOT, and adjusted so there was about 1/4 inch of slack..

Sometimes it idles high, but it dies down within 5 seconds. I dont get it, but im not gonna worry about it.