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View Full Version : Rough idle, CEL



mpaganr34
04-28-2011, 09:08 PM
Yes, I searched. I did.

My 530 has had a perpetual rough idle, but on and off. Well, it's on again.

So, on cold starts, the car will barely start, but if I give it gas it'll stay running. Then it will proceed to sputter, cut out, catch itself, and come back to life. Over and over and over. Once it's up to temperature, the issue goes away for a while but will come back at stop lights here and there.

I've replaced every gasket known to mankind, checked with starting fluid for vacuum leaks, and replaced the MAF and ICV. The issue fixes itself and then comes back, it seems. A few months ago, I unplugged the MAF and plugged it back in, which caused this problem. It fixed itself a few hours after. I recently (last weekend) replaced the upper timing chain gasket, which required disconnecting the battery, alternator, and air intake, including the MAF. When it was plugged back in, the rough idle reared its ugly head again.

I stomp tested and got 1213, which I've never had before. The check engine light seems to come on and go off while I'm driving.

Today, I ran it and unplugged the MAF. It would rev every time I unplugged, which would indicate that it knew there was a MAF there, right? The catch: it ran better with the MAF unplugged. So we've got it narrowed down to something probably sending the wrong signal to the MAF, but what could it possibly be?

Any help?

tl;dr Go back and read it, you need all the details.

Nuckles
04-28-2011, 09:30 PM
Have you replace the throttle body gasket? and the maf is it a bosch.

AHenry014
04-28-2011, 09:43 PM
find someone with a maf and swap it out

mpaganr34
04-28-2011, 09:44 PM
I have replaced the throttle body gasket. Let me double-check, but I'm roughly 100% sure.
The MAF is a Bosch.

Edit: Meh. I don't think there's anyone in the area that has a 530 MAF, and they're bucks to go buy one. I'm not sure the MAF itself is bad though either, because this is the second one I've had on and it's doing the same thing. This also seems to only happen after I unplug it. Is there possibly something I've forgotten to plug back in, or something else I've done wrong?

mpaganr34
04-29-2011, 12:38 AM
Update:
I am a buffoon. It seemed odd that I would be the only person with an M60 throwing a 1213 that wasn't a vacuum leak, so I retested. Turns out the last few times I tested for vacuum leaks, it wasn't reacting with the carb cleaner.

Flooded the engine with some starting fluid, and the engine revved when spraying both sides of the intake. Looks like I get to take that off and replace all those gaskets for the third time. Getting good at it.

lovinlyfe4dub
04-29-2011, 01:46 AM
Sounds like a sticky idle air controller to me.Take it out and clean it with carb cleaner or replace.