Please help ,
I replaced my opti after no start condition from a bad cardone opti. Now it runs like crap the idle evan sounds funny. It burped when i tried to get on it to see if it clears up and it threw code p0100 MAF malfunction i cleared it and it hasn't come on since.

I had them scan it at work with the tech 2 and there were no codes, no missfires, the fuel curve looked good (not my words), o2 sensers were working properly, this was all at idle.

When I drove home it would stumble when I tried to get the rpms up, and it had a rough idle. I miss the sound of my cam. I checked the plug wires to the opti with help and all are were they should be. I was really wanting to take this thing to O.C four cruisin not looking good.

Ive searched for a couple hours and feel like im spinning in circles. thanks for any help

 

I just unplugged both o2 sensors while running and no change in idle .

I then took the MAF sensor off and cleaned it with MAF cleaner. drove it down the road and back. It still feels the same what i did learn though is at WOT it doesn't brake up. it only breaks up at acceleration not wot.

Can an ICM going bad cause this condition or just a no start/intermitant start (keeping in mind this is a cold start and drive so no heat soak).

Not sure what to check next.

 

Did you forget to connect the Opti vent vacuum line?

 

thanks for reply fred,
i checked the vacuum from the intake manifold and it is hooked up and run properly and I have vent line running from the back side of the opti to a dry area in the engine bay. (its open i havn't found any filters small enough to fit it. but the previous owner had nothing runnig from it and it ran fine just rusted out the original opti.

 

My opti vacuum line runs into he intake elbow. I had to drill a hole in my Aluminum elbow for it when I bought it.

Also, Would the vacuum line not being connected cause it to stumble? I mean it was added just to pull the ozone and excess moisture out, right?

 

are you sure the new opti is good? a lot of people seem to be having problems with bad quality optis that dont work

 

[QUOTE=calaban;6692203]My opti vacuum line runs into he intake elbow. I had to drill a hole in my Aluminum elbow for it when I bought it.

my car is supercharged so my vent can't go to the elbow.


Rv93. Yeah iwas one who had badluck with junk optis I put a a/c delco in it this time I would be very dissapointed but thanks for replys

 

I don't think not having vents hooked up will affect the way it runs just longevity. But the vacuum hole on the intake manifold would have to b capped off im guessing

But mine r hooked up ( well like I posted earlier the back half is vented open)

 

I don't think not having vents hooked up will affect the way it runs just longevity.

That's what I was getting at with my post.

 

I wasn't suggesting that not hooking up the vacuum line would cause a problem with the Opti's operation. I though it would be reasonably obvious that it would result in a vacuum leak at the manifold, which might be enough to cause a stumble under moderate load, but not at WOT.

 

Fred,
I see what your saying I just read another post u chimed in on about incorrectly installing the opti. Now im 99.9% sure I lined the square different shaped hole on back of the opti to dow pin on cam side. But I read that on the vented optis if its wrong it wont fire at all because of how far off it would be is that correct?

Just trying to get that possibility out of my head.
Thanks

 

Is there a possibility that this problem exisited before the opti change?

Did you check the fuel pressure and the vacume line that connects to the regulator?
Engine vaccume reading at idle?

 

thanks for reply,
i have an electronic fuel pressure gauge and fuel pressure is good.

its actually drivable just has around 1200rpm idle and stumbles, when it does i watch my wide-band and a/f will jump araound obviously.

im going to thoroughly go over all the vacuum lines when I get back from o.c. my brain hurts for now. i was really hopin to get a few tickets this weekend at the cruisin, lol

thanks