Greetings. I hope some of you can help me with this crazy problem.
I have a '94 Volvo 850 non-Turbo. Two weeks ago, it died just after I started it, and would not start again. It would crank, but not start. It didn’t even act like it was going to start. There was plenty of fuel in the tank. Anyway, I had it towed to a shop. It started right up for them!!! They tried for 3 days to reproduce the problem, and it never did it for them.
When i went to pick it up, it would NOT start for me! So I went back and got the mechanic. He came out, and it started right up for him. He was baffled. I was baffled and annoyed.
Anyway, he said he had a few theories but couldn’t find anything wrong. Fuel pressure was ok, spark was ok, etc. So I left.
Yesterday, the car died on me while i was driving (at a steady speed). I pulled over, it would not start. I tried about 15 times over the span of 10 to 15 minutes. Then, suddenly, it started right up and I drove home!
Any ideas???
Mechanic’s theory was a crank angle sensor or a cam position sensor… but he said these tend to fail and STAY failed. They don’t magically heal themselves intermittently.
The car has high miles, but has been maintained. Air filter is clean. Fuel filter has not been replaced recently… but why would it clog and then unclog itself?
Any ideas or tests I can perform would be most appreciated!
Follow up I forgot to mention: The Check Engine light is NOT on, and the engine temp at the time of the problem is normal or below normal (ie, the car hasn’t been on very long).
In case that helps anybody.
Shot in the dark solutions don’t always work but I used to suspect the throttle position indicator which used to cost fifty dollars on an old Tempo. Somebody should try to read the computer codes first and work from there. I don’t like Volvos myself so I can recommend a new car and you will know that my opinion is biased. Battery terminal cleaning sometimes helps if the car just misses a beat without stalling out, but who knows if it will help the Volvo? The symptoms you described would suggest different problems. I kind of ignored the part about the engine not starting.
Even if the CEL isn’t throwing, I bet a code is. That would be the first step for me (to check codes, then look them up), and that could pinpoint the problem. If not, it sounds vaguely familiar to a few of the modified Mustangs i’ve had that have a fuel pump reset button in the trunk that would always seem to solve that issue.
I have had cam position sensors on Ford diesels fail intermitently. Some have even been temperature sensitive and will restart after ten to fifteen minutes cooling only to fail again shortly. Did mechanic run the codes? I believe sensors can be tested when removed, but if you are going to do that, then just replace them.I would suspect an intermittent relay is causing the trouble. Possibly for the fuel pump or ignition areas.
I had a Ford that when the computer got hot it would die while driving.
Your mechanic is right that sensors generally break, and that’s the end of it, so I doubt it’s a sensor of any kind.
Cougar’s right too - it’s almost certainly an intermittent electrical signal to the distributor or coil. Power is not actually making it to the plug wires when the problem appears, due to an intermittent short upstream of the wires somewhere. I had an identical problem in a Mitsubishi and that was the solution.
Check for any fault codes that the ecm may have detected and related to the symptoms…failing camshaft sensor,engine speed sensor,etc…if none,verify fuel pressure by connecting fuel pressure gauge when it doesn’t start…tapping on gas tank with rubber mallet awakens a failing fuel pump while cranking engine…using a jumper wire to bypass fuel pump relay is another test procedure u can do to eliminate a failing relay…even checking the basics a poor or loose battery connections…now u have a starting point and good luck…