1994 850 Base Stalls in Wet Weather

Barcelo_850 · Post by **Barcelo_850** » 02 May 2014, 23:34

So to give some background I've owned my 94 850 for just over a year now. Bought it with 121k mi. through a Volvo dealer mechanic that knows the car better than anyone, as he did all the work for the PO. He does everything for me as I live in Boston, and lack not only the tools, but the space (ok,ok and for the most park the knowhow) to do much of any work myself. He does the work on the side, and cuts me a great deal since I continue bringing it to him (last year I had him replace my evap core that I bought online for $40, he put it in for $300. Would have cost $1200 anywhere else). Point is, he knows the car and certainly knows Volvos.

My biggest problem right now is that for the last 6 months or so, it idles really rough and then dies when the conditions get wet. If it rains or we get a wet snow, or if I drive it through a big enough puddle, the car will start up just fine, but after a few minutes of city driving it will start to idle poorly. Then, if I stop, say at a stop light or stop sign while its idling rough, it will die once I press the gas to get going again. At this point, it will not start for about 30 minutes. It will crank and crank and crank until the battery dies, but I've learned that if I just let it sit for 20-30 minutes and crank it, I can eventually convince it to turn over. Once I get it going again, it will still idle rough for a bit, and will sputter and sometimes stall again when i hit the gas, but if I just let it run, it goes back to normal and I'm on my way (usually home).

The first time it happened I brought it to my mechanic, and he had it for 3 days trying to figure out what it was. He replaced the battery, removed and cleaned the idle control valve, and put in a used throttle position sensor. The cap, rotor, plugs and wires had just been done when I bought it, so he left those alone. He gave it back to me thinking it was fixed, but I think the weather had just improved, so it was no longer acting up. Since then it's died on me about 4 or 5 times. Most recently at the arrival terminal at Logan airport. State Troopers loved that. I've tried misting water under the hood at night looking for sparks, but didn't see any. Any ideas/suggestions?

Post by **jreed** » 03 May 2014, 05:30

Cleaning the IAC valve would have been among the first things I would have suggested, but you've already done that, so that's good.

Some questions in random order:
Have you checked to see if you have spark and fuel when the symptoms occur?
Does the fuel pump run when you experience the crank/no-start symptom?
Are the battery cables or terminals corroded?
What brand of cap/rotor, wires and plugs are you using?
Is the check engine light on?
Good luck!

Post by **mecheng** » 03 May 2014, 06:16

I agree with jreed what brand cap and rotor is it, and wires? If it's cheap aftermarket crap it could
Have a poor seal. Spray liberal amounts of wd-40 on the cap and wires to see if it improves

Barcelo_850 · Post by **Barcelo_850** » 03 May 2014, 10:16

Cap and rotor as well as the coils are all bosch. Not sure about plugs/wires, but I can only assume they are oem quality, as he does all the work at the dealership.

Battery terminals are fine, and the battery is only about 6 months old.

There seems to be spark, because it always cranks as long as the battery has some charge.

Now the fuel I'm not so sure about. Each time this has happened, I'll sit and crank it desperately, and about every 5-10 seconds of cranking I hear a low toned "thoom" in the exhaust. After letting it sit for the 20-30 minutes I can crank and it will gradually catch over more and more until it finally starts.

As for the CEL, it has only come on once while the symptoms have been present. However, the scenario was a bit different. It wasn't/hadn't been snowing or raining. I drove it just down the block and was stopping in at a convenience store. I turned a blind corner on my right and did a sort of "turn corner/simultaneously do a u-turn into a parking spot" maneuver, but didn't realize the spot I was pulling into was full of hard packed ice about 4 inches deep. So the car bottomed out, right in the middle of the chassis, right about where the fuel filter resides. When I went to start it up again it was the same old story. Cranked until the cows came home. What was different was that it seemed the car was being suffocated, because I could smell exhaust very strongly inside the car. Thats when the CEL came on, in fact it may have even been flashing. So I waited it out. Lo and behold, 30 minutes later it came around, and after a couple minutes of running, and a push out of the parking space by 3 good Samaritans I was able to drive it home and the CEL went away on its own.

Post by **jreed** » 03 May 2014, 11:20

Can you hear the characteristic "whirring" sound of the fuel pump running when the car cranks but doesn't start? If not, you might have an intermittent fuel pump relay, or fuel pump.

Post by **Ben850** » 04 May 2014, 08:00

Buy Bougicord plug wires. Nothing else. Both of my cars ran strange in damp weather until I replaced the plug wires with the Bougicord (OEM) wires. They are also date stamped to ensure they have not deteriorated on a shelf somewhere in a warehouse.
Lastly, you mentioned the coil. Bosch only. The longevity is pretty good on these, but depending on the climate the car comes from, it is subjective.
Cam timing sensor connector also caused a problem on my '93 Sedan. It was cracked and I didn't notice it until changing the distributor cap.
I did get a salvaged coil and cam timing sensor. Those and new plug wires have had it running well for the past two winters.

Good Luck.

Barcelo_850 · Post by **Barcelo_850** » 04 May 2014, 09:54

Just went to check the date stamp on the wires, and they are dated Jan. 2011. While I was checking around though I did notice there is a thin black wire spliced off of the blue wire that plugs into the ignition coil. No insulation or electric tape used, just the black wire wrapped around the blue, both exposed. The black wire seems to run into a wiring harness somewhere around the back of the airbox/abs module. No clue what it might go to. It just seemed like an easy opportunity to get wet and short or jump a ground or something.

Post by **abscate** » 04 May 2014, 10:36

Just had a thread where a bad MAF was the culprit for this.

Try unplugging and seeing if car will suddenly run.

Post by **Ben850** » 04 May 2014, 13:03

Barcelo_850 wrote:Just went to check the date stamp on the wires, and they are dated Jan. 2011. While I was checking around though I did notice there is a thin black wire spliced off of the blue wire that plugs into the ignition coil. No insulation or electric tape used, just the black wire wrapped around the blue, both exposed. The black wire seems to run into a wiring harness somewhere around the back of the airbox/abs module. No clue what it might go to. It just seemed like an easy opportunity to get wet and short or jump a ground or something.

That sounds like a tap for an aftermarket tachometer or other timing device. Unshielded or non-encased wiring to the coil would not be good in any case.
If there is/was an aftermarket tachometer installed, either tape those wires, or unhook them and seal the area.
EDIT: I have an afterthought. Is your '94 an early model with VVIS manifold? If so, there is an electronic vacuum solenoid that actuates the manifold variable with a diaphragm. That solenoid would be screwed onto the air box. It is activated at a specific RPM. My '93 is of that type and I have modified it to act a bit different from stock.
Link here.
https://www.matthewsvolvosite.com/forums ... 7&start=14
Once again good luck.

Barcelo_850 · Post by **Barcelo_850** » 04 May 2014, 17:20

Sounds like the MAF might be the most likely culprit. I'll have to wait until the next time it rains and stalls, and disconnecy it. As much as I'd hate to have to drop $150, at least it will be an easy swap. As for the ominous exposed wire, I'll just seal it up. If it aint broke...

Thanks everyone for all the suggestions.