- August 7, 2006
- Reaction score
- City, State
- The center of Hell, Parker, Arizona!
- Year, Model & Trim Level
- '91 XLT
...Any updates on this???...:scratch:
CAn you try another PCM...mine had a similaor issue...and the PCM was the culprit.
Ran great put a circuit on the PCM board went and would not 'see' a sensor's voltage properly.
It is possible to have an "internal" vacuum leak at the manifold gasket.I have found a few like this by pinching off the breather hose and PCV hose.Shoot a small amount of carb cleaner into the valve cover and see if your RPM's change or idle smooths out.
Also take a look at your air intake duct between the MAF and throttle for any cracks.
Did you get this straightened out yet? Mine is doing this all the sudden. I put new heads on it, it ran great for about 1500 miles starting last january, and now, all the sudden, it idles like it has a giant cam in it...
I know you said you check the MAF but if you unplug it that sets the PCM to a default value for incoming air amounts. So if it's running bad with it in, but runs good on default values, it's probably the MAF. Another thing to check if it's missing on 1-6 is to listen to it run for about 30 seconds. Shut the truck off and pull cyl 1 plug wire off the coil pack and start truck. Repeat this going from 1 to 2 to 3...etc...until you hear a change in the engine's running. If you hear no change, then it's not something limited to one cyl. Good luck!
More problems with my 91 hunk o shit. Still have the rough idle issue, SHITTY gas mileage 10mpg, but now when the truck is hot it REAKS of fuel when I park it.
If I park and run into a store for 5 minutes I can smell gas BIG TIME and the truck BAIRLY runs till the temp gauge goes back down to "O" from like "M" or "A" on "NORMAL". It idles like its running on 3 cyl.
Remember I just spent $3000 putting a Motorcraft longblock into this POS. The new Long block has less than 1000 miles. I can't find a drop of gas leaking anywhere, but man can I smell it when the truck is warm.
...I quoted from your new thread (http://www.explorerforum.com/forums/showthread.php?t=221117 ) to here, so we can read the previous known problems too...
...Have you pressure tested the fuel rail yet???...:scratch:...I would also check for leaks around there before you start a fire...