Mine acted the same when my MAF was damaged of coarse I stabbed mine when I was 16 trying to get the screen out for free HP 300$ mistake!

 

sorry to thread jack, what type of business or auto shop offers a "smoke machine" to check for leaks? If i was searching for such a service, would i just be calling random auto shops or dealers, or is there a specific type of service i need to look for?

 

unplug the maf to see if its any better....computer will run in SD, and a oily maf will be irrelevant.

 

Many dealerships and some independent shops have smoke machines, nothing "special", but an expensive tool. You'd have to call the shop(s) of your choice and ask if they have one. We have one here at the Lexus dealership that I work at, but just bought it from SnapOn less than a year ago. Most commonly they are used for EVAP leak diagnosis, but can be used to check multiple different systems on the vehicle.

 

Don't go to a shop for a smoke machine.....find a buddy who is a chain smoker. Tape a piece of hose in the TB, and duct tape it closed. In a well-lit area with no wind, have him blow into the hose........Nearly free!

 

Atomic
We tried to unplug the MAF it didn't really change anything. other than throwing MAF codes.
There is 1 other thing I for got to mention. It sometimes wile driving at normal temp would go into open loop on the fuel trim sometimes its only for the lenght of a stop light others for 10 min and it runs poorly. and wile all this is happening no code get kicked out!
This has all mechanics puzzled.

Don

 

LOL, I can accommodate that...parts and labor would include 1 hour diag time and a pack of Newports

That's weird...I wonder if you have a loose or corroded ground somewhere, or maybe a faulty PCM? PCM failures aren't common, but it does happen. Since there was a Hypertech tune in there, something may have gotten "corrupted", just like a laptop at home.

Do you know someone with a similar van with a MAF that you can swap in? Sometimes unplugging sensors won't do the trick. Although, if techs have been watching the MAF activity with scan tools and the readings are within specs, that should rule the MAF out...

I'm assuming that fuel pressure has been checked and it's OK...

 

I Have a pcm form an 04 express but Im told they are different, but the service tag on then have only 1 # different and its in the small #s not the large. So I have to check out the pcm to see if it will work and try it out. Fuel is 60psi. The rough idel was intermittent now its all the time, so your theory about a bad connection could be correct. Any chance a bad cam or lifter cause it to idle rough and then cause all the codes?

The other thing I wanted to try was cleaning all the coil connections on the control side and using some dielectric grease to insure a better connection. when I do this I will take a look at the rest of the harness to see about a bad ground.

Don

 

Ok Guys
First off thanks for all the responses I really do appreciate the effort!

This morning I swapped out the MAF I unplugged the battery for 10min and held the pos and neg wires together for 15sec. put it all back together and it ran worse at first gave it some gas and got better. But the rough idle missing is still there only now when u give it throttle and let off it feels looks like its going to stall then idles up again.

shut it down unplugged the MAF started it up sputtered at first gave it throttle and it idled up but the rough idle and missing was again still there.

One other dealer I had questioned about my issue said it maybe a bad cam.
Could A worn cam lobe or two cause my issue?

Thru all my testing Ive noticed it runs rough up to 1k rpm then it levels off.

Any Ideas?

Don

 

I think its a fuel issue...weak pump will make trims go high like that since it cant the pressure up. When you checked the pressure, did you just prime the pump or was it idling or what?

Friend of mine had a similar problem except the pump was fine, but the fuel pump wiring was faulty. It would build pressure on prime and start, but couldnt keep enough power to the pump while running.

I would keep the guage on the fuel pressure at prime and while running and see what happens to it as you raise the rpm.