I have a 2001 V6 Mustang Convertible that has never given me problems in the 12 years that I've owned the car (I took delivery with 1.5 miles on it). In the past year, it started running rough like there was a misfire, but only when I got on the gas, so I would drive it easy to avoid this problem.

About a month ago as I was backing out of my garage, it just died and wouldn't start. It would crank, just not fire...not even an inkling of starting. I did some simple tests and found a bad secondary coil pair in the coil pack (which is why it was running rough), so I replaced it. Tested for spark but...nothing; no spark. The coil pack needed to be replaced anyway; I even tested the new one with an ohm meter before leaving the parts store.

So I towed my car to my trusty mechanic who diagnosed the problem as a bad PCM. I authorized a replacement and he towed it to a Ford dealership to program the new one. The dealership programmed it and it started right up. When my mechanic went to pick it up, it wouldn't start...that was almost a MONTH ago! The dealership has been fooling with it (supposedly) everyday trying to identify this issue of intermittent starting, even put in another new PCM and original PCM (at my request, but the old one did nothing). I then insisted that they call Ford's service tech hotline because maybe some other dealer in the country has run into this. They say they did and were directed to run a series of tests, but the car won't act up long enough to complete the tests or tell them what the issue is. The dealer threw the possibility of a bad instrument cluster out there. They also said that they have never seen this problem before.

PCM was bad, that I'll concede, but I have a couple of questions for the super techs out here:

1. What are the chances of the PCM AND instrument cluster going out at the same time?

2. What is the possibility that the tech that installed/programmed the PCM fried the instrument cluster in the process?

3. If the cluster were bad/fried, would the car start intermittently or not at all?

4. Anyone ever run into this type of stubborn problem and found the solution?

This dealership is one of the largest ones in the metro area, so I would think that they know what they're doing. Thank you for any help you can provide! I love my Fords, just not their PCMs!

 

Have they verified proper fuel pressure?

 

I would HOPE that a dealership would test that, but you never know...I think these guys are clueless. I do know that before I took it in, I bled the fuel rails multiple times and each time there was fuel in them after turning the key to "ON".

 

Many of these mechanics are clueless. I could tell you stories. Tell them if they can't fix it, take it to someone who can.

 

I told them that I wanted a loaner car while they screw around trying to get mine fixed, and they basically said that if I wanted them to start testing wiring harnesses to find the problem that they'd have to start charging. So I told them to get it started and MY mechanic shop would come pick it up. So now my guy has it and will try to track down the issue.

If he needs to take it to another dealer, I'm going to have him take it to where I bought it. I know they know what they're doing.

 

When electronics are involved , just about anything is possible.
Just because there was fuel at the schrader valve on the fuel rail means next to nothing. The fuel has to be there at a certain pressure and volume.
As you know by this time , intermittents are one of the techs worst nghtmares.
It is possible the dealership assigned the job to an inexperienced tech and that is their mistake.
Understanding your frustration, I believe your latest decision to take it to another dealer is a good move.

 

I had a Buick v6 that had a simular problem..start and run fine then after 30 miles ..quit..would sometimes restart sometimes not till the next day..turned out to be the wireing to the crank senser was broken in such a way that as the wire heated due to the connection ..the circuit was broken..when the connection cooled the car ran..this may be happening in the crank senser also..just food for thought