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Forum nameEngine Management Systems & Controllers
Topic subjectwont hold idle....common mistakes w/ engine rebuild and MSnS
Topic URLhttp://forums.2gnt.com/dcboard.php?az=show_topic&forum=54&topic_id=1008
1008, wont hold idle....common mistakes w/ engine rebuild and MSnS
Posted by White97rs, Dec-31-69 06:00 PM
just curious if there are any common mistakes made that would cause the car not to idle at all. i have to constantly flutter the gas in order to keep it running. my WB is fluctuating between 13.5 and 15.2. But the car runs extremely rough and will not hold idle at all. just curious if there are any common mistakes made after a engine rebuild that would cause this. I know timing is a obvious issue, but i was wondering if any other possibilities would be present, that i may have over looked due to extreme simplicity. also, excuse this question but, im tired. I have my MSnS hooked up correctly when i have INJ 1 firing 1 and 3 and INJ2 firing 2 and 4 correct? any help will be appreciated, sooner the better. I gotta drive this bad boy down to Ocean Isle in about 4 weeks.
1009, RE: wont hold idle....common mistakes w/ engine rebuild and MSnS
Posted by Star Turbo Talon, Dec-31-69 06:00 PM
You gotta give us a little more info there.

1st. engine rebuild.....was the ms&s running the previous engine and how was the idle?

2nd. if running spark did you tune the VE before you hooked up the spark to the MS?

3rd. Have you tried hooking the new built motor to the stock fuel system?

Checked for the obvious?.....vacuum leaks, cam timing, connected the IAC and all harness conns?

That will help a little
1010, RE: wont hold idle....common mistakes w/ engine rebuild and MSnS
Posted by DarkOne, Dec-31-69 06:00 PM
Try to eliminate variables one by one. If you can, let the stock ECU control spark & fuel for a short while and see if the problem persists. if it does its not the timing, but it might be the MS wiring or the config of your base maps.
1011, RE: wont hold idle....common mistakes w/ engine rebuild and MSnS
Posted by White97rs, Dec-31-69 06:00 PM
yeah sorry about the vagueness (sp*) of my post... No the car wasnt previously tuned with MSnS, i am currently running MSnS but no spark it is only controlling fuel until i get a good fuel setup. My motor is forged rods low comp pistons (howell bottom end kit), 525cc injectors. i am almost positive the timing is fine because i checked the timing marks last night and they lined up perfectly to my eye. As far as vaccum leaks.....i have no clue, i have no loose vac hoses, to my knowledge. Im pretty sure it has somethign to do with the tuning. I need some serious help in this area. any one who would have the patience to help through this will be much appreciated. I thought loading a basemap from someone else with similar setups would atleast get me started and idling but i am mistaken.
1012, RE: wont hold idle....common mistakes w/ engine rebuild and MSnS
Posted by Star Turbo Talon, Dec-31-69 06:00 PM
Ok well I have the 550 injectors and the idle should not be too hard to achieve, keep in mind i have about 20 hours here and there of adjusting idle only to find the best combo. I spent a whole week working on the idle before i dropped the new motor in.

Dino is on the right track. since you installed the MS and motor at the same time then run the motor through break in on the factory Fuel. Breaking inthe motor while trying to tune is a real bad idea. You will have a lot of time tied up in the idle and the consequence will be a motor brokenin by idling forever.

On that motor what is your vaccuum?

Good idea working on fuel only first, its the best way.

This shouldnt be too hard just time consuming
Terry
1013, RE: wont hold idle....common mistakes w/ engine rebuild and MSnS
Posted by White97rs, Dec-31-69 06:00 PM
well it holds idle, still a lil rough but it holds. my vac at idle is a lil above 15 hg. Im gettin there, slowly but surely.
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