I've been having some troubles trying to figure this out, when my car is on its cold loop it idles perfectly around 900 rpm. But once it warms up my idle goes to about 2000 rpm. Just curious if anyone else has had this issue or if maybe something I've done is just going screwy

 

What year car?
What mods?
What MegaSquirt?
Post Tune
Post Log showing both conditions
Post an introduction… maybe start there. It is sometimes considered impolite to walk into a room talking.

 

It's the first time ever on a forum for me so I'm not in tune with the necessary etiquette required. Sorry! I'm Colby and I have had my 1990 Miata with a 1.6 with a MS PNP 2 turboed for a while and was running totally fine until the end of the season last year when I ran into this problem all of a sudden. I was running about 12 pounds on an old turbo when I upgraded to a 2871 Garett and now run 20 pounds of boost. I was spiking lean so I figured I would see if maybe I was having an issue with my injectors which I had upgraded to a 320 at that point. This is also when my car started having the afore mentioned problem. So I figured I'd try my luck with some new Bosch 750cc injectors. (Cause maybe I crapped out an injector. Idk why I thought that but I did..) so I tried that and still the same issue so I tried both injectors and fiddling around with my ecu a bit (I am an absolute noob with ECU tuning and know very little bit ut wanted to try for myself as I have no one within 600 kms to take it to get it tuned. good ol' northern British columbia) I figured then that my problem may lie within a vacuum leak and I managed to get it idling good for enough time to let me go around with a propane bottle and squirt it around to see if I had a vacuum leak anywhere and nothing showed up. What confused me at this point is I had the car running with no flighty idle and a nice idle at 900 rpm. Then I turn the car off to see some stuff go to turn it on about 5 minuets later and the thing just shoots up to 2000 rpm. Sorry too for the long description. As for posting up my tune and data logs I am unsure about how to do that.. I'm very sorry. @DNMackinson

 

I figure in the end my problems fall withing my incapability to properly tune my car.

 

To post tune, click “Go Advanced”, then “Manage Attachments”. Then you follow instructions to upload files. It is a go or idea to save out your tune first as something other than “current tune” so that people who may download it have a unique ID.

Are you saying that you are running a stock ‘90 on 320cc injectors at 20 psi with a 2871?

I personally don’t have experience with MS2’s, or 1.6’s with non-variable throttle position sensors. So, I won’t be able to help.

One parting suggestion, However, go back and parse your long post into paragraphs for easier reading. You’ll get more responses if your posts are easy to read.

 

Okay, thank-you for your help!