I've been working on isolating a rough idle/stalling problem for a little over a month now. No CEL codes, intermittent stalling while driving down the road, sometimes the car would restart right away, sometimes not. Sometimes when restarting the idle would be very rough and then the car would die.

I replaced the fuel filter, pulled, inspected and bench tested the fuel pump and master relays, cleaned and reseated the MAF cable, the problem cleared up for awhile, then she just died on my wife. I couln't get it to restart long enough to drive more than 500 yds before she would die again.

Finally, I called a wrecker and had her towed to my local indie. I had been toying around with the idea of pulling and rebuilding the fuel pump, as well as replacing the fuel pump relay, but had run out of time.

I spent $336 and she is running just fine now. The mechanic did the following:

Replaced fuel pump relay, $75. Could've saved $20 on that part from FCP Groton. He explained that they check the date of manufacture on the relay (mine was original) and if it is 10 years old or more, they routinely replace them if the problem is fuel related. When I inspected it, I saw no cold solder joints, no oxidation, when I applied 12VDC, the relay switched well, the points looked good. I suppose it could have been "flaky", though.

Replaced the coolant temperature sensor, $57. It was corroded and he said that these fail so often that he always has 3 in stock.

Replaced the thermostat and gasket, $20.

Drained, flushed and refilled the cooling system with water and antifreeze $15.

Labor, 2 hours, $150 (all my numbers are rounded off, the bill is filed and it's late while I write this).

These last three items combined to cause my runability issues, I believe, and here is why:

I had been driving the car some to work to try to troubleshoot the problem and had noticed that the coolant gauge seemed to display colder running temperatures (slow to warm up) than I had remembered (my wife's car, I don't get to drive it too much). Also, the day she finally quit, I was able to get the car restarted for a few minutes a couple of different times. I noticed that the temp guage needle was slowly drifting up and down around the midpoint of its range. It wasn't erratic or fluttering, and the drift was only about +/- 3% of the total range. I suspect that the cold running was due to the thermostat being stuck open, and the drifting gauge was caused by the corroded temp sensor.

So, maybe you guys with the same problems can check these items and save the labor cost. Several other brickboarders have suggested routinely replacing the fuel pump relay as they age - that would be a good place to start, IMHO.


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Ten Sleep 1980 245DL 1995 850 Turbo 1997 Dodge Dakota 5.2L "Silence is golden, but duct tape is silver"