trouble63

sorry guys, put the first post in the wrong place.
anyway I built the engine in my mustang about a year ago.
i'm having a bad surging problem,and sometimes it shuts off when I put it in gear. when it was bone stock it ran great.
I put a E303 cam in it also had some head work done.
I had a chip burned for it and had it back to the tuner 3 times. looked at a lot of forums, and tried a lot of suggestions.
changed the tps,aic, and egr . still having the same problem.
anybody have any ideas?
thanks,
jim

dawson1112

Have you pulled the codes to see if the computer has stored anything?

Clean the MAF ,
Check to be sure you don't have a vacuum leak. some times the egr valve vacuum solenoid will be bad and cause the egr to remain partially open . The vacuum solenoid is located inside the passanger side wheel well , You can safely unplug all vacuum lines from the egr valve and cap them off . If you remove vacuum lines from egr and cap then and the car runs normally its likely the vacuum solenoid stuck .

trouble63

already cleaned the maf, and I did check the egr solenoid everything is checking out good. I am wondering if by changing the cam if it has changed the vacum
I did a vaccum test and it's only pulling about 13 1/2 .

dawson1112

Did you do an Idle relearn? What is your idle surge range? is it low drops below 500 will stall the engine almost surely. And yes cam swap will lower your vacuum , probly see 12-15 on the gauge with that cam. I think an idle relearn may help you out. and you will want to set the idle to about 750-850 rpm at idle.

http://www.muscularmustangs.com/idlereset.php

You did have the battery dissconcted for the cam install correct ?

trouble63

no didn't do an idle relearn , but will do so. yes battery was disconnected I rebuilt the engine so it was out of the car. idle surge is between 600-1400 rpms

dawson1112

Do the idle relearn and shoot for the 750 mark , Drive the car and let the computer learn the new flow numbers.

Some times you just have to drive it awhile . These cars have adaptive learning and a big change in air flow will have to be adjusted for by to computer.

trouble63

ok did the idle relearn, still have the same problem. drove it to myrtle beach for mustang week, which is about 90 miles each way.
I didn't say when it was surging. it surges when I am at a stop in gear, doesn't do it in park.
has me dumb founded

trouble63

by the way, nice stang

dawson1112

Thnx man..

You still havnt pulled codes ?

And the car idles good in park ?? Only hunts idle when in gear?
What is your idle when in park?

Your sure you don't have a vacuum leak? Did you make sure all the injectors seated and none of the O-rings were cracked or split.

Maybe a bad pcv valve.

I would see if the computer stored any codes ,

It could be a vacuum leak at one of the injectors. as the engine rpm rises and falls the vacuum rises and falls pulling on the oring and sealing it for a moment then as vacuum falls off unmetered air enters and rpm shoots up. Computer is constantly trying to find the base idle that it was set to operate at so it continually opens and closes the iac valve. Same could apply to a small crack in one of the plasic vacuum lines or the rubber connector that the red green and tan lines plug into. ( and im guessing the tan color lol I know 2 are red and green. )

Proper way to check for vacuum leaks is by using a smoke machine to apply a low pressure smoke into the intake system and watching where any smoke escapes.

trouble63

no it is not pulling any codes and I did do a vacuum leak test with a smoke machine.
I deleted all the emissions solenoids and lines kept egr and ran new lines for egr.
the tuner I use has burnt a chip for it, which is a diablo. the car has E303 cam,
with xpipe using stock intake and plenum right now. could that be my problem?
and also using stock heads with some work