Official Engine Stalling Thread

Guest · Post by **Guest** » 24 Jun 2005, 10:02

Day 40 here after 2nd quickie cleaning (w/o removing TB from engine). Still OK.

greg94/854 · Post by **greg94/854** » 25 Jun 2005, 18:56

i've posted b4 on this issue

there's a 50/50 chance my '94 854na 185k will not restart after short trip to run in & out of store i.e. get gas. otherwise, it's a great 29mpg high speed cruiser.

the other day, it died @ stop sign, restarted instantly.

hours later, it wouldn't start after work. i had friend crank it while i depressed fuel rail shraeder, no gas. after poking around and talking nice to it for 20 minutes it started and ran like a new car for the 20 min hi speed trip home. (?????????)

greg94/854 · Post by **greg94/854** » 25 Jun 2005, 19:01

i'm sorry, also no codes

Post by **matthew1** » 25 Jun 2005, 19:12

Sounds like fuel pump or pump relay.

greg94/854 · Post by **greg94/854** » 25 Jun 2005, 19:24

thx matt
I'm going to inspect the relay first, as I'm not a parts changer and i feel the fuel pump failure would not be sporatic

Jon · Post by **Jon** » 26 Jun 2005, 10:30

Andrew,

You asked about the humming coming from aournd the TB/ETM(whatever) and everyone seems to have ignored it.

The sound is normal. The Idle valve works with a ~60Hz pulse width modulation. That's what's causing the sound.

To everyone else,

Great info. I have a few things to try to fix the stilling problem I have myself.
'93 850 GLT 5-speed, 171k miles, usually gets 30mpg highway (though that's dropped lately, might need to clean the TB). While cruising at constant speed, in two cases at about 40 and once on the highway ~70-75, the enigne will die, but I can't even tell until I step on the gas and there's nothing there. No CE light, no noise, no drop in RPM (it's in gear and still rolling). Just as if the key had been turned off and back on. After 30sec to 3 mins, it will start again and drive fine. So far it seems to happen about every 15 hours of driving time.

I'm going to check the fuel pump relay and do the TB cleaning. Hopefully one of these things will take care of it.

tims 850 stalls again · Post by **tims 850 stalls again** » 27 Jun 2005, 18:18

Pls add me to the 850 stall problem. Yes there are enough reported and many many more unreported cases of 850 stalling, common thread, stalls while being driven, worse in hot weather, primarily when decelerating, at lights, turns etc. It will restart after a few seconds usually about 30s. May recurr within 10 minutes or 10 days. My 1994 850 2.3L 5 cyl turbo uses (I think) Motronic 4.3 controls yet the "book" says the Motronic 4.3 was only used on the 1995 model. It has been doing this for stall 2 years, mechanics cannot pinpoint cause. I have cleaned the throttle butterfy valve, replaced the IAC valve, replaced the throttle switch, what next?? Fuel pump relay - where is it hidden?? Intermittent problem sounds like an electrical/electronic device overheating and then cooling and resetting. The ECM is located in the hot engine compartment - seems a poor design location for such a critical computer. Any fresh ideas?? Surely Volvo can help by at least issuing a helpful hints bulletin - without any liability. Stalling suddely can be dangerous - should this be allowed to persist

Timmy

digital1 · Post by **digital1** » 28 Jun 2005, 00:33

The reasons for stalling are numerous.

Thats why nobody could pinpoint a perfect solution for every case.

Reasons could be as follows:-

1) Electrical problems. Electrical supply to ECU interuppted. Solution is to clean contacts at battery terminal. There is a separate cable from terminal to ECU. This reason has already been brought up at volvospeed chat forum.

2) Fuel supply problems. the famous 104 relay. Fuel pump relay not functioning perfectly. Clean contacts and or replace. Check fuel pump too.

3) Transmission problems. Incorrect selection of gear by auto trans. this is due to the speedometer sensor at the back of the trans. the rpm sensor and or the crankshaft sensor. Solution is to remove the sensor clean it from all metall filings; and reinstall or buy new one and install. This is the most common reason and accounts for most stalling at turns and decelerating as incorrect gear selection results in loss of power and immediate stalling.

4) Battery problems. Undervoltage at battery due to alternator / battery problems. These causes ghost problems and throttle position sensor voltage problems. replace battery and or check alternator.

hope this helps.

regards
stlim

Guest · Post by **Guest** » 28 Jun 2005, 08:00

digital1 wrote:The reasons for stalling are numerous.

Thats why nobody could pinpoint a perfect solution for every case.

Reasons could be as follows:-

1) Electrical problems. Electrical supply to ECU interuppted. Solution is to clean contacts at battery terminal. There is a separate cable from terminal to ECU. This reason has already been brought up at volvospeed chat forum.

2) Fuel supply problems. the famous 104 relay. Fuel pump relay not functioning perfectly. Clean contacts and or replace. Check fuel pump too.

3) Transmission problems. Incorrect selection of gear by auto trans. this is due to the speedometer sensor at the back of the trans. the rpm sensor and or the crankshaft sensor. Solution is to remove the sensor clean it from all metall filings; and reinstall or buy new one and install. This is the most common reason and accounts for most stalling at turns and decelerating as incorrect gear selection results in loss of power and immediate stalling.

4) Battery problems. Undervoltage at battery due to alternator / battery problems. These causes ghost problems and throttle position sensor voltage problems. replace battery and or check alternator.

hope this helps.

regards
stlim

from what I can tell/have read extensively about, would like to add

5) IF STALLS WHILE DECELERATING, can almost gaurantee it's a dirty TB/ETM (or "bad" ETM, very expensive to replace so try removing and cleaning yourself or take it to dealer, say this defect is getting well known now and insist they clean it for you).

6) If it stalls while driving at normal speed and it won't restart until it cools slightly, besides possible electrical mentioned and fuel pump/relays in this thread, could also be (mine was) a bad CPS (camshaft position sensor). It's located right on top of the engine on drivers side, very excessible, hardest part is disconnecting the electrical plug (seems to be a theme on Volvos). If you have the special tool for the 2 bolt heads (like allen wrench only different shape) it's a DIY job.

Guest · Post by **Guest** » 29 Jun 2005, 20:25

Just wanted to mention that since I've posted on my stalling problem, I narrowed it down to temperature and fuel related. Replaced the Fuel Pump relay and the problem is fixed. Car starts everytime now.