I've got an odd idle problem. I'm idling at between 200-400 but mainly at 200. It's been like this since the head job but all the timing marks line up fine. I'm not sure how to go about this. any tips or suggestions?

vacuum leaks

tps not reading correctly.

IAC not working right.

plugs not firing correctly

i am sure that I missed a few

Originally posted by bedlam32570
I've got an odd idle problem. I'm idling at between 200-400 but mainly at 200. It's been like this since the head job but all the timing marks line up fine. I'm not sure how to go about this. any tips or suggestions?

how much did they shave off the head?

adjustable cam gears?

whats your vac gauge read at idle?

it can actually idle at 200? wtf? you sure your not trying to say 2000?

If its 2000
then my money is on a vacuum leak

Originally posted by Chamuko
it can actually idle at 200? wtf? you sure your not trying to say 2000?

With my speed sensor unhooked, my mustang will do this for a few seconds, then shoot up to the normal 800 or so RPMs. It's a very rough idle, but it can do it.

yeah 200. I didn't mistype it. I'm gonna go through my sensors and check for any vaccuum leaks to see what I find. I've got no adjustable cam gears but I am thinking I should get some. I have a set of crane street cams on it but I know that's not causing it cause i didn't put them on until I did the rebuild and it's been doing this since before than.

IAC.

how does it run at cruise and under throttle?

response under throttle is a little slow but once it hits it, it goes. the check engine light came on so I am gonna get it scanned and see what it says. I am suspecting the EGR Valve might be the problem.

I dont think that the egr would cause that low of an idle because I have had mine blocked off for a while now (I just recently hooked it back up) and it would always idle normal unless there was a vacuum problem.

When the egr opens and the IAC would close my idle would stumble a little but it would just throw a cel and then pick back up.

What is your AF when it is idling that low.

haven't checked it. I haven't had the time to go to indepth on it. I do know I'm running lean though.

if your idle is at 200 (way less then it should be) I really doubt its a vac leak. I mean, a vac leak would Allow MORE air in.

well it's not the IAC, not a vaccuum leak, and not the TPS. I'm gonna try the EGR, and do a tune up just to have that done. I'm running out of what it is. I have a header on it and believe I have some exhaust leaks. I'm thinking that might be contributing to it. I was gonna swap back out to a standard manifold and downpipe. Ever since I put the header on I've had problems with the exhaust not sitting right.