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Forum nameEngine Management Systems & Controllers
Topic subjectIssue with MS/hanging idle
Topic URLhttp://forums.2gnt.com/dcboard.php?az=show_topic&forum=54&topic_id=3788
3788, Issue with MS/hanging idle
Posted by eclipse982nrRST, Dec-31-69 06:00 PM
I have a small issue that I have come across.

Usually 80% of the time it happens when the engine is warmer, when you give it some rev's, the idle will just hang around say 2k-3500 RPM. Is there something that is wrong in my settings or anything like that, that someone knows of? Or anyone had this issue before?

I am running just fuel, no spark yet.

Thanks in advance as always.
3789, RE: Issue with MS/hanging idle
Posted by Slo2g, Dec-31-69 06:00 PM
This happens to me, I don't know why it happens but it eventualy goes back down. You got me, i am still trying to get someone to take a look at my logs/graphs. :(
3790, RE: Issue with MS/hanging idle
Posted by Star Turbo Talon, Dec-31-69 06:00 PM
its all in your tuning of your fuel map. Things like this are why we recommend you run fuel only first.
3791, RE: Issue with MS/hanging idle
Posted by eclipse982nrRST, Dec-31-69 06:00 PM
Originally posted by Star Turbo Talon
its all in your tuning of your fuel map. Things like this are why we recommend you run fuel only first.


I agree. That is why I am starting out slowly with fuel only.

Thanks Terry. I will be starting to fine tune things here within the week, and hopefully have her on the road by next weekend.
3792, RE: Issue with MS/hanging idle
Posted by mreigle, Dec-31-69 06:00 PM
I had the same issue using a stock TB bored to 55 MM with a larger insert to fit the 55MM. At a friends suggestion I finally gave up and put jbweld on the tip of the IAC to hold in in the closed position and then installed an idle set screw. My idle has been perfect ever since. If I need to adjust it up or down I just turn the screw.

Old school FTW :)

3793, RE: Issue with MS/hanging idle
Posted by eclipse982nrRST, Dec-31-69 06:00 PM
Originally posted by mreigle
I had the same issue using a stock TB bored to 55 MM with a larger insert to fit the 55MM. At a friends suggestion I finally gave up and put jbweld on the tip of the IAC to hold in in the closed position and then installed an idle set screw. My idle has been perfect ever since. If I need to adjust it up or down I just turn the screw. Old school FTW :)


I have the MP 60mm.

My idle is fine though until I give it some gas, then it will hang there usually at that RPM it was rev'd up to.
3795, RE: Issue with MS/hanging idle
Posted by Star Turbo Talon, Dec-31-69 06:00 PM
Mike, check the set screw. I found mine to be slightly open on the MP when i got it. With fuel only, give it tiem and practice and you should get that baby to idle like factory (maybe slightly rich). Mine would be in the high 13's low 14's until i drove it and heat soaked it. Dont kill yourself on the idle right away, get it close and work on driving it. I had over 40 hours in my idle and with tunign i had to adjust it anyway over time. Idle is what you will spend the most time on.

When you run spark you will need to block off the IAC. There is a 3 penny trick or you can put a sleeve behind the pintle like i did.

Terry
3797, RE: Issue with MS/hanging idle
Posted by eclipse982nrRST, Dec-31-69 06:00 PM
Originally posted by Star Turbo Talon
Mike, check the set screw. I found mine to be slightly open on the MP when i got it. With fuel only, give it tiem and practice and you should get that baby to idle like factory (maybe slightly rich). Mine would be in the high 13's low 14's until i drove it and heat soaked it. Dont kill yourself on the idle right away, get it close and work on driving it. I had over 40 hours in my idle and with tunign i had to adjust it anyway over time. Idle is what you will spend the most time on. When you run spark you will need to block off the IAC. There is a 3 penny trick or you can put a sleeve behind the pintle like i did. Terry


Honestly Terry, I do not plan on running spark until next year.
I will be the first admit, I even scared to drive on the road with this installed for the first time as I am sure every one else was too. Just dont wanna blow something up, haha.


3798, RE: Issue with MS/hanging idle
Posted by Star Turbo Talon, Dec-31-69 06:00 PM
Mike you might find you liek the factory map and just stay with it. I think its a great map for a street car and it gives an excellant idle and great throttle response. The only way to get the most out of your own spark map is to either get very good at tuning it or dyno tune it. Dyno tunig isnt cost effect since you and I are always changing something.

Terry
3800, RE: Issue with MS/hanging idle
Posted by eclipse982nrRST, Dec-31-69 06:00 PM
Originally posted by Star Turbo Talon
Mike you might find you liek the factory map and just stay with it. I think its a great map for a street car and it gives an excellant idle and great throttle response. The only way to get the most out of your own spark map is to either get very good at tuning it or dyno tune it. Dyno tunig isnt cost effect since you and I are always changing something. Terry


I am going to get tuned before the SO this year and make it to the SO FINALLY to meet everyone and take her down the track hopefully for the first time this year, but I am going to try my best and get a good street tune down with it.

Do you have a copy of the factory map you could send me Terry?
3805, RE: Issue with MS/hanging idle
Posted by Star Turbo Talon, Dec-31-69 06:00 PM
no you just run spark only genius...lol come on. plus you get the protection of knock control without having to add shit.
3817, RE: Issue with MS/hanging idle
Posted by Ready4Dis, Dec-31-69 06:00 PM
I would check your minimum threshold for your TPS, make sure it's going all the way below this, although that would typically cause slight choking due to extra fuel, just a quick check to make sure. Also, what are you using to control idle? Stock ECU? Things to check would be, make sure your EGR valve is closing all the way, make sure your PCV valve isn't sticking at all, etc. Could be a small vacuum leak coming from somewhere, takes a few for the stock ECU to compensate. Hard to really diagnose over the computer, but those are a few things to check.
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