Car Hiccups

Dear Car Talkers,



I have an issue with my manual '82 Volvo DL Wagon. At random times, it “hiccups” as if there were an air bubble in the gas line. Sometimes there is no consequence and I just continue driving, but other times, all the dash lights come on, it dies, and I barely have time to make it to the side of the road. Sometimes I can restart it without a problem and go on driving; other times when I restart, it hiccups again and again as I continue driving. A couple times, I could restart it if I wait a few minutes; other times it stays dead and I’ve had it towed.



It does this sporadically and doesn’t seem associated with heat, cold, driving distance, driving time, what gear it’s in, terrain, or anything I can identify. Sometimes it does it for a week or two, then is fine for a couple of months. This has been going on for over a year.



Then, about a month ago, I started having erratic problems with the turn indicators. The indicators don’t go on at first, then do, after driving a couple of miles. It’s almost like they sometimes need to warm up to start working. Once they begin to work, they stay working during that drive.



I’ve had it in to my trusted mechanic (Volvo specialist) who has been servicing the car the past 18 years. Once when it was towed there, it started right up for him and he couldn’t diagnose any problems. Another time we traded cars for 3 weeks, again after it was towed to him, and he didn’t have any problems. The only thing he thought might be a possibility is the wiring harness and he worked on it, but didn’t replace that (apparently it’s an expensive project to replace it).



I bought this car new and have had all service done and regular (3,000 mi) oil changes. It has about 260,000 miles on it and has been very reliable up until this issue. I’d like to hang on to it, but this behavior scares me as I don’t want to have or cause an accident if it stops somewhere dangerous.



Thanks, and I appreciate any thoughts or ideas.



cmb

Portland, OR

It’s possible that the problem is in the wiring. It might help your mechanic find the fault if he does wriggle testing of all the wiring in the engine compartment and under the dash. This is done by shaking and moving the wiring as the engine runs. If the engine stumbles, that section of wiring contains the fault.
Of course, a fuel filter change, and fuel pressure test, with engine under load, should have already been done. Were they?

Thank you for your response.

The fuel filter was changed with a tune-up (4/08). I’m not sure if a fuel pressure test has occurred to try and diagnose the problem. The fuel pump was replaced (8/09) after it broke during diagnostic testing, so maybe that testing was the fuel pressure test. The fuel pump relay was also replaced.

As for wiring, our mechanic said that he found a loose connection at the hall switch which led him to believe the problem could be in the wiring harness, ignition controller, or hall switch itself (2/09).

The next time we bring the car in (hopefully for an oil change and not this problem) I’ll have the mechanic do a wriggle testing of the wiring and see if that helps diagnose if the problem is caused by faulty wiring.

cmb