1994 850 Nonturbo constant stalling

Post by **MadeInJapan** » 21 Dec 2014, 20:23

This is an early year '94 so there are many '93 features such as a different MAF sensor and it has an EGR.
It started stalling a few weeks ago at stop lights...this progressed to stalling right after starting the car and then not starting back up...eventually, it would start again but then would die before you could get it in gear. It shows no codes. I worked on it all day today. I replaced the Fuel Pump Relay and the main Fuel Injector Relay (FI), checked the CPS and behind the rotor and cap for oil- clean as a whistle. The temp gauge is stable and I believe correct. The fan comes on as it should if you drive it for awhile. There is pressure at the fuel rail and the Fuel Pressure Regulator appears to be fine as well. It just stalls and has gotten worse. It stranded my son last night and I had to go get him and leave his car parked to take him home and then go and get him again today. If the temp gauge was acting wonky I would suspect the Coolant Temp Sensor or sending unit but that doesn't appear to be the problem. The MAF was unplugged and it made no difference except that the car threw a MAF code and a Idle Air Controller code. I cleaned the IAC as well as trying a different one. At one point after replacing the FI Relay the car drove like nothing was wrong (most of the afternoon) so I thought that fixed it but tonight after my son and I congratulated each other for fixing the thing, it's doing the same thing. Oh, also during the start-stalling-no start- stalling periods, there is a heavy smell of gasoline.

I have tried to cover all of the bases. I read here on MVS last night from about 11PM to 3AM trying to figure this thing out and systematically tackled all the likely culprits but now I'm completely stumped.

I hope you can help me- best regards!
MIJ

Post by **shaker_chi** » 21 Dec 2014, 21:02

Looks like you did quite the once over. Did you take a look at the ignition coil. I had the same issue with my early 1994 850 and the plug came loose. It was still making contact, but once I hit a bump it would kill the engine. Visually, you can't tell its loose because of the boot.

Also, you stated you checked the Cam Position Sensor. How did you check it? Resistance, Ohms? It may be on its way out. If its the original sensor you might as well replace it because eventually its going to go.

Good Luck.

mika · Post by **mika** » 22 Dec 2014, 08:50

shaker_chi wrote:Looks like you did quite the once over. Did you take a look at the ignition coil. I had the same issue with my early 1994 850 and the plug came loose. It was still making contact, but once I hit a bump it would kill the engine. Visually, you can't tell its loose because of the boot.

Also, you stated you checked the Cam Position Sensor. How did you check it? Resistance, Ohms? It may be on its way out. If its the original sensor you might as well replace it because eventually its going to go.

Good Luck.

Probably not it but...
2nd chime in on the ignition coil.....there is an ignition plug wire that goes from the pack to the distributor. When you buy new plug wires, this one is not included. I have had one cracked so bad it was arching sparks out of the wire (you could see it with lights out); I was missing and shaking quite a bit.

Post by **cn90** » 22 Dec 2014, 08:51

I understand you have fuel at rail but maybe the pressure is not high enough.
? Bad fuel pump.
Search for Bosch 69693.

PS: Check the ignition coil, but this part rarely goes bad. Also spark plug condition, cap/rotor/ Bougicord, Fuel Filter.

Post by **MadeInJapan** » 22 Dec 2014, 09:45

Yes, ignition coil is fine. The CPS may be another story. At the junk yard I almost had one loose- the screws undone but it wouldn't budge. No, I did not do an ohm test- I really got confused by the videos on Youtube on how to do this and what the numbers mean. I suppose it could have an intermittent problem. My mechanic also told me to just replace it as it probably needs it anyway. Funny thing is I gave one in good working order to a friend (she never used it) but she's out of town for the holidays. I could buy one but nothing off-brand I trust and the dealer wants like $150 for one. I guess the car can sit for awhile. We go out of town tomorrow morning for several days.

Post by **MadeInJapan** » 22 Dec 2014, 10:13

That's the price I saw on line
For sh%ts and giggles I called my local Volvo dealer to see if they had one and if it was reasonably priced. No, they don't have it but could get it for me by tomorrow. $273.44.
Do people really pay these prices for this stuff? Gee.

Post by **cn90** » 22 Dec 2014, 12:31

Bosch CPS is about $85 on ebay.
But since you are shooting in the dark, get the junk yard CPS as a guinea pig.

Post by **MadeInJapan** » 22 Dec 2014, 17:28

Well, Yes I am...The car set a code (finally)...a look up with the A2 (fuel) button revealed MAF...
Gee- after all of that, it may just be the MAF. Anyway, I have a CPS coming to me and a guy hunting a MAF for this car. One bit of confusion- this is evidently for '93-'94 850's (non-turbo) and also '95 if it's non-turbo and manual transmission. Bosch #0280217002 Interestingly, ebay sellers claim this will fit other 850 years and even s/v/c/xc70's for '98. I'm not sure if that correct. Can anyone verify? If I can use a MAF for another year, I'll do that- otherwise I'm tied to this specific one that is hard to find. Btw, the meter is integrated into the lid of the airbox so it's not a "T-Tube" like most, but I have found that that I can eliminate the lid, replacing it with a lid that takes a T-Tube so fitment is not an issue if the newer style will work with the '94 850 NA. Thanks for your help!

Post by **dosbricks** » 22 Dec 2014, 18:48

I can't contribute anything regarding your specific '94 year, but will say that the S70 did the same thing--dying at stoplights and then progressing to be becoming harder and harder to restart. New CPS, fuel pump relay, CS, etc. ($$$) did not fix it.

It was the MAF. Also tried unplugging the MAF as an indicator but that didn't pin it down either. It must have been a case of intermittent missing info the MAF should have been supplying.

Post by **Ozark Lee** » 22 Dec 2014, 19:58

Was the TSB modification to tuck the camshaft and crankshaft position sensors away from the ignition wires with a zip tie done? Interference to the sensors from the ignition wires can also cause stalls. In their natural state the sensor wires loop up to the bottom of the distributor.

...Lee