CornerCarver,

Fantastic...I think those are all good ideas and that's the direction I'm going to head (I'd like to avoid buying a new PCM if at all possible) so I'm hoping it's the MAF connection or circuit which would make my life easier and much cheaper.

Dan

 

I'd recommend looking at a shop manual on CD if you have one, lol.

Seriously, you've got some good suggestions here. I have a mass-air Stang that had similar problems, turned out it was an air leak. It seems possible that you might have accidentally pulled a line while working on it.

 

I had that go bad on a 97 Explorer V8 I had a few years back. It would crank and crank, but not turn over at all.

 

Topsy,

You a funny man! Believe it or not, I actually do have a shop manual on CD and I poured over that thing last night and it was less than helpful to say the least. I have double- and triple-checked every vacuum hose, wire/connector and astrological chart I could access. I'm going to call around today to see if I can find a good Mustang or electrical shop in the greater Phoenix area to see if they can troubleshoot the MAF connector and circuit which should help me narrow it down (to a bad PCM at that point).

I'll keep you posted,

Dan

 

I say Check the vacumme line that runs from the bottom of the intake boot to the upper intake/IAC motor. Mine got melted and did exactly what you are talking about. It would not ideal, but would run ok when you got on the gas. It was a very simple thing with a very easy fix

 

Try this: Unplug the connector from the MAF and the EEC. Read the prongs in the connector to see if any are shorted together or shorted to ground. Don't use a continuity check since it will not give a resistance reading. Then look at the electrical drawings and see if this corresponds to the EEC pin-out diagram and the wiring schematics. It's a start.

 

Actually, the first thing I would do is buy a code reader, and query the computer. I would guess that it will either point to a problem sensor, or if you get O2 lean/rich codes, it's probably a vacuum leak.

Good Luck, btw, you sent me a CD, heh.

 

And the saga continues...taking it to a different Ford dealer tomorrow. Having them pull codes (with no chip or breather cap which should clear the code that I was previously getting) and test the MAF connector and circuitry along with the PCM. The good news is that the PCM is allegedly flash reprogrammable (if that's what's causing the problem) to the tune of an hour's worth of labor and if it's completely fried (which I find hard to believe since the truck still runs fine without the MAF) a brand new one is only $240 plus overnight charges. Not cheap but much less than what I was quoted at the first dealer ($800 for the PCM...get bent!).

Dan

 

And CornerCarver wins the online troubleshooter of the month award...which is really good for nothing but bragging rights! Turns out the issue was caused by a pinched wire in the MAF wiring harness (the pinch appeared to have been there from the factory since the truck was new and it finally started causing a problem the other day). Tech at the dealer managed to troubleshoot and fix it in about an hour and under warranty - even after initially informing the Service Advisor that the truck was no where near stock (as opposed to the trained monkeys at Bell Ford who couldn't manage to find the problem after 8 hours). Truck runs like a champ again and if my plugs all check out okay this afternoon than it is off to the dyno tomorrow.

Just as aside, it seems that lots of people complain about dealers and techs, but in this case both the service advisor, Carl Brown, and the tech, Bo, did a fabulous job (and both will have the beverage of their choice waiting for them when they get off work tomorrow). If you live in the greater Phoenix area I warn you to avoid Bell Ford like the proverbial plague and hopefully I can steer you to Lou Grubb Ford in Scottsdale.

Dan

 

Thank ya, thank ya very much!: Glad they fixed your problem.

 

Dan
Thats awesome news, I figured it had to be something like that.

 

Dan glad to hear they worked it out!Talk to you soon.

Later,-Dave.

 

Struck in AZ
Good to hear you found out what it was. Your problem was exactly like the one i had with my truck it was surging rpms going up and down then stalling truck wasnt holding idle. Me and Sal couldnt figure out what the hell was wrong we swapped pcms eveything i was at his house all day. Finally i broke down and stripped her and took her to the dealer had to go in anyway for the intercooler recall. Well it turned out after the dealer having my truck for well over a month that it was first a blown motor from them which i knew was bs. Then a bad lower pulley balancer forget what they said but i got the updated 01 version i know that , then finally they came up with what was the real problem a bad ground for the PCM. That was causing all my trouble probably from when i got into my accident with the truck Sal said he saw lots of cars that needed the PCM replaced because of the accident. Now the truck hasnt run better.