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Strange loss of power issue with my 94 940 non-turbo. Short trips in morning to work are no problem. However, if I drive somewhere, take say 45 minutes with the car off during an errand, subsequent use results in intermittent loss of power. As if fuel starvation. Recovers on its own after 10 or 15 seconds, only to repeat power loss later during same trip. Never seems to be an issue after the car has not been driven for a while, as in overnight. I have little history with this car, but do have good records from previous caring owner. Fuel filter has 20k on it. I see no receipts for fuel pump or relay ever having been replaced, and the car has 198K on it.
Thanks.
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Dear yenna,
Hope you're well. Does the car have Bosch engine/ignition management (round coil mounted on passenger-side strut tower or Rex/Regina (Bendix) engine/ignition management (square coil/ignition module mounted on driver-side strut tower)
Cars with Rex/Regina engine/ignition management have a single in-tank fuel pump. At 198K, that pump is beyond its service life (about 150K miles). If the car has Bosch engine/ignition management, '94 has an in-tank fuel pump and a main pump mounted on the underbody, below the driver's seat. At 198K, either could be "on the way out".
Another possibility, if the car has Bosch engine/ignition management: the ignition power stage - mounted on the driver's side inner fender wall (just to the rear of the headlight) - could be failing. This unit, flat with a pale gray plastic cap, could account for intermittent ignition issues.
A final possibility is that the ignition switch could be failing. I had one fail on a '93 940. Engine cut-out but would re-start. The key clue was that ignition switch failure killed power to everything, including the emergency blinkers. Thus, if during your car's intermittent operation, other electrical systems were normal, then it is not the ignition switch.
Hope this helps.
Yours faithfully,
Spook
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Thanks spook. I have the Regina system, and have had same on two previous Volvos (93 940 and 90 740). I agree, the fuel pump is a must, and I fortunately saved my spare new one (with screen) from previous 940. Also, I checked fuel system error codes earlier today. I get 2 - 2 - 1, signifying heated oxygen sensor problem. This got me scouring previous owner records again, and there is no mention of this having been done either. That's hard to believe, but the code is what it is. I'll probably set aside half a day and do both jobs. Fuel pump I've done before, and with my dental floss loop to keep things aligned when replacing sender with pump attached, it should go easily enough. Or not.
Thanks again,
Doug
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Dear yenna,
Hope you're well. At the risk of laboring the obvious, when comes time to do the oxygen sensor, apply lots of penetrating oil (Kroil, PB Blaster) to weaken corrosion bond between the sensor and the catalytic converter housing. If possible, apply the penetrating oil daily for a week before trying to turn-out the sensor.
Pageda's suggestion about coil grounds is excellent!! The coil contacts should be cleaned with a electrical contact-safe orrosion-dissolver (Deoxit or similar). I'd then apply a light coating of di-electric grease, to keep moisture away from the contacts.
Hope this helps.
Yours faithfully,
Spook
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Thanks again. Going to start the PB Blaster regimen today. Cleaned and tightened grounds, noticing some peculiarities with CPS wiring at the time. Back to the records! Last replaced in 1995 under a recall. So, frantic search through my spares (having had Regina cars for 2.5 decades), and I do have a new Bougicord CPS. Installed it post haste, several test runs, no problems. Old CPS was frayed to copper wire showing at sensor end, frayed too at connector end. That may be the proximate cause, although I am on a mission to do fuel pump and oxygen sensor before they fade as bogeys from my radar.
Thanks for all the help! I remain loyal to the Goose. (name for my metallic blue-green 94 940 - kinda suggesting Blue Spruce, which quickly morphed into the Spruce Goose for some reason. Naming fate sealed when I discovered previous owner of 18 years has phone registered in McMinnville Oregon, home of the Spruce Goose museum.)
Right,
Doug
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Dear yenna,
Hope you're well. I apologize for having to tell you that the crank position sensor (CPS) is found on cars with Rex/Regine engine/ignition management.
A 22-year-old CPS probably gets you a Guinness Book entry!
That the CPS wires were exposed by deteriorated insulation explains the intermittent engine shut-downs. When moisture caused a CPS short-circuit, the engine control module lost the CPS signal and so shut-down the fuel pump.
Thanks for posting your findings.
Yours faithfully,
Spook
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Dear yenna,
Hope you're well. Pls. disregard first sentence anent presence of CPS on cars with Rex-Regina engine/ignition management. I mis-read your post. Mea culpa!!!
Yours faithfully,
Spook
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Also search for information about the about the coil for the regina system, there can be issues with grounds on them.
Dan
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