New member, same old problems :)

[sasquatch094]

Hello fellow delorean owners!
Lets see where to start. My delorean has had this high idle since i could remember and now its to the point where i want it fixed. Around start up itll go around 2000 rpms then drop to about 1700 maybe 1600 rpms. The car has around 8,000 miles and is all original. We tried fixing this problem without the use of internet and through the service books and PJ Gradys help but still no luck. Ill try uploading a video to Youtube for some diagnostic help, it almost "whistles" when idling. very annoying to say the least.
Ive tried spraying carb cleaner on possible vacuum leaks with no luck, unless theres a usual spot where they go?
Ive also tried to adjust the idle with the 2 screws
Tried cleaning the contacts on the Bulk head connectors as well today. they all seems to be in good shape
It seems like the butterfly may be too close or not letting enough air in? Does the butterfly usually hit the rubber bump stop? mine doesnt even come close and its probably a good 1/4" away when its shut off...


Any help?
http://img269.imageshack.us/img269/8216/0805121759.jpg (http://imageshack.us/photo/my-images/269/0805121759.jpg/)

http://img7.imageshack.us/img7/539/1344199866587.jpg (http://imageshack.us/photo/my-images/7/1344199866587.jpg/)

http://img21.imageshack.us/img21/1296/0805121758.jpg (http://imageshack.us/photo/my-images/21/0805121758.jpg/)

[DMCMW Dave]

Can you get it to idle down by pressing the throttle closed with your finger? If not, the decel valves are probably bad and sticking open.

Read the whole thread, but this is the important part:


http://dmctalk.org/showthread.php?722-Backpressure-on-throttle-lever-at-idle&p=7406&viewfull=1#post7406

[sasquatch094]

opps, before i was talking about the air intake "butterfly or flap" in the center of the intake manifold.. if i press this down while its running, (adding more air obviously) it calms down the rpms...

I check the idle switch as if im not sure if i said that before, i disconnected it while it was running and the idle skyrocketed..

[Elvis]

That's the air measuring plate and it adds more gas.

Please try the SEARCH function, it works fantastic bringin up at last 200 threads concernig high idle.

[sasquatch094]

Elvis, im not new to forums. im not new to the search button, if you cant help, move on.. Ive read every high idle one and still cant seem to find out what it is..

[Jonathan]

Just getting back to the throttle assembly and idle speed motor microswitch... are you saying it is that lever arm which is not falling back far enough to depress the microswitch? You can see from the rear when you manually rotate the throttle assembly with your fingers that the linkage will cause that lever arm to pivot off and on that microswitch button. When the throttle spool is relaxed, it should be engaging the idle speed motor via that microswitch. If it isn't, you can adjust the set screw on the lever arm to give it some more travel.

It might also be related to there not being enough slack in the throttle cable. Is your car an automatic or manual? On the autos, there is a secondary cable which travels from the opposite side of the throttle spool to the auto trans shift computer assembly. Perhaps if that was too tight, it's not letting there to be enough slack for it to go back to it's proper rest position. Again, if yours is an auto, there are also two microswitches there and they affect the idle speed motor and also the kickdown gear logic.

[sasquatch094]

I have to double check the slack Jonathan

Ive uploaded a video finally, you can hear the whistle, not sure if this is normal or not? after playing around with the cable more, it seems to backfired on me. When i hit the gas just a little bit, the rpms keep climbing to about 3000 rpms then i can blurp or hit the gas pedal fat for it to come back down
http://www.youtube.com/watch?v=r61N3RwfdCQ

[Cory W]

Out of pure curiosity, try wiggling the electrical connector on the idle speed motor while the car is running. (I didn't see that you had done this before, just disconnected it) I'd been chasing an intermittent high idle for some time until I found this was my problem.

[DeLorean03]

Here's my thoughts. First, check this diagram out:

12343

Go to your car and remove that black throttle spool cover/shield. This will allow you to access the trottle spool assembly. It is seen in this picture as the circular spool assembly with the red circle around it:http://dmctalk.org/attachment.php?attachmentid=12344&d=1344273826

Now, with your engine off, slowly and smoothly turn the throttle spool, as if you're wanting to increase the RPMs on the engine, but listen for a very small "click." If you hear it, that means the mircoswitch switch screw had the idle microswitch pressed down before you "revved the engine." Now, let the throttle spool assembly go all the way back to resting position (as if you wanted to lower the RPMs), and listen again for that "click" as the throttle spool goes all the way back to resting position. If you hear a very tiny "click", the idle microswitch is being engaged and works as it should. If not, the microswitch screw can be adjusted to make it reach and enable the idle microswitch - takes a 8mm wrench.

Now say you are hearing the microswitch get enabled by the microswitch screw, and yet, you're having this high idle problem. If that happens, rev your throttle spool hard and fast a couple times. If that clears it up, your throttle cable that runs from the throttle spool to the acceleration pedal needs to be lubed/replaced. If it doesn't clear it up, take your finger and gently press on the tip of the microswitch screw. If you hear the engine RPMs comes down, that also hints that your throttle cable needs to be cleaned/lubed/replaced. Can get it from SpecialTAuto - $89: 12345

That's my thoughts on it - for now.

[Elvis]

Elvis, im not new to forums. im not new to the search button, if you cant help, move on.. Ive read every high idle one and still cant seem to find out what it is..


So then did you test the ISM ?

the ECUs are also known to fail - the simple tests - I'm sure you read them already.

What were the results ?

[Jonathan]

If you can "snap the gas" and it comes back down, I am betting at least part of your problem is that the throttle cable is pinched somewhere between the spool and the pedal in the driver's footwell. Mine has had the same symptoms in the past and it could be related to this. Interesting what Cory said there about the connector being slightly off or a poor connection. I'll definitely be trying that "wiggle" advice next time I'm at my car :)

[sasquatch094]

Well i found out the big hiss or whistle which is the gasket on the left tube (http://store.delorean.com/p-6433-tubes-throtmfld.aspx )
I was spraying more carb cleaner around those bras screws when i found that gasket/vacuum leak. If i put my finger over it, the sound goes away but the idle doesnt smooth out at all.

On the other side, when playing with the cable, it seems like the lever with the adjustment screws is pretty worn or loose? you can move it a decent amount without the cable even moving. I got the idle to sit around 800 to 900 when playing with that alone. I think i really need some new cables and to lube up the springs since ive read they carry some heavy friction under them.

Im going to keep playing around with it and see what happens, getting rid of the whistle already making me happy.