1994 Volvo 850 stalls, slow restart...with a wrinkle

Hi everyone,

I have a ?94 Volvo 850 and a while ago it started stalling. It has a bit of a rough idle that has improved a little with non-ethanol fuel and fuel injector cleaner. I honestly don?t know if that is related to the main problem.

The main problem is the stalling. Sometimes, it will just stall when I?m stopped at a light. Sometimes, it will stall when I?m going 30 miles an hour. Sometimes, it will stall when I?m going 70 miles an hour. Typically, when it stalls at slower speeds or at the light, it just dies straight away. When it dies at higher speeds, the first thing I notice is "hitch" or a "bump" sensation at which point the engine stops responding to depression of the accelerator pedal. The engine continues to run for a few seconds as I roll along. The tachometer slowly falls and then the engine dies.

There was a time when I could throw it into neutral and get it started again before coming to a complete stop from highway speed, but those days are gone. It seems that it is taking longer and longer to get it restarted. The car has to have the key in the off position for a minimum of 10-15 seconds before it will even have a chance to restart. Lately, after about 30 seconds to a minute it will restart very briefly and then immediately die. If I?m patient and wait a bit longer it will restart like normal, but it seems more likely to die again if I don?t wait a generous amount of time.

This problem seems to very rarely occur during long trips, but I can?t tell if that is relevant or just secondary to the fact that I take I take relatively few long trips. Of course, if it were completely random it should occur more often during these 5 hour trips since it seems to happen so often on the shorter trips.

It?s been to the mechanic at least twice for this problem. The mechanics say that the car is not displaying any "codes." They replaced the fuel filter the first time without improvement. The second time, it was in for other things too and they were unable to "recreate" the stalling despite driving it for 40 miles. They said that without any codes or being able to recreate the stall, they didn?t want to just "do something."

I?ve read some posts from people with similar cars and problems. Seems like the things that come up most often are the fuel pump, fuel relay, and oxygen sensor. However, only the fuel pump and fuel relay seem to be mentioned when there are no codes. Is that at all accurate? Do the symptoms the car is having seem more compatible with the fuel relay or the fuel pump or something else entirely. I haven?t tried to "listen" for the fuel pump when it happens before, would that be likely to help?

Thanks a ton for any help.

Pid

Reply to
pidgas
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That sounds exactly like what my 740 did. I don't know how similar the engines are, and I actually doubt they are similar enough for this to be the cause of your problem, but.....mine was caused by the auxiliary air valve pipe, right on top of the inlet manifold, working itself loose. Check yer pipes! :)

Si

Reply to
Mungo "two sheds" Toadfoot

Could be, my '80 260 did exactly the same. It happened once, stopped dead and would not start at all. So dead I didn't believe that could stop it, even after I noticed the hose had fallen off one end.

Reply to
jg

Long shot, but worth a go- try waggling the key in the igntion with the engine running. If the engine dies you've foudn the problem- ignition switches are a known weak point on the 850.

If thats ok, it sounds like a dodgy fuel pump relay to me.

Tim..

Reply to
Tim..

Exactly - I was thinking that something major had died!

Si

Reply to
Mungo "two sheds" Toadfoot

A good point - my 740's ignition switch takes very little turning to stop the engine.

Si

Reply to
Mungo "two sheds" Toadfoot

"pidgas" escreveu na mensagem news:1_684675 snipped-for-privacy@autoforumz.com...

Reply to
Adriano Silva

"Tim.." escreveu na mensagem news:diikjt$kkr$ snipped-for-privacy@nwrdmz02.dmz.ncs.ea.ibs-infra.bt.com...

In my case, was the first thing they have done (at Volvo): changing the ignition switches.

The problem remain the same...

Reply to
Adriano Silva

Air mass meters can cause this without leaving a code, believe it or not. The fuel pump relay (#103 under the cover behind the fuses) and the main relay (gray relay above the rad beside the fan relay) can also cause you this kind of grief. Also the engine speed sensor can be the culprit. Of course there's no way to tell without trial and error, unless the failure happens when you're in a position to troubleshoot.

Reply to
Mike F

You forgot to mention the cam position sensor (which would probably leave a code), an erratic sticking fuel pressure regulator, various vacuum leaks that may or may not trigger a code, restricted throttle housing, chafed or rubbing harness that could be faulty anywhere, water in the fuel tank, a partially restricted fuel sock on the fuel pump pickup, loose or partially backed out terminal in one of the banana plugs under the dash, a faulty coil or coil wire, wrong spark plugs, loose or leaking turbo hoses, sticking EGR valve or a restricted or leaking PCV system. I agree, you kinda' have to be there when it happens in order to get some idea of which way to go.

Bob

Reply to
User

I could use those last two paragraphs as the opening for my autobiography!

My '74 Ford 4wd pickup- when I got it, after some effort, it ran great. Then after a bit, it would just die after running various amounts of time (ten to 30 minutes). I would work on it at the side of the road, and then, without reason, I would get in it and it would fire right up and run great.

One time when it died, I took the top off the carb and the float bowl was empty. It ended up being rust in the tank that clogged the fuel filter. Stop the truck, gravity would settle the rust, and off she would go again. Even after a change of fuel tanks (get a NEW one) and flushing of the lines, I put a replaceable filter in the line before the fuel pump it still happened. I still had to clean the filter every two weeks or so for months before it stayed clean.

And DON'T EVEN GET ME STARTED on Air Mass Meters! ;-) I have three tested and working spares now.. OK, so I'm paranoid!

__ __ Randy & \ \/ /alerie's \__/olvos '90 245 Estate - '93 965 Estate "Shelby" & "Kate"

Reply to
Randy G.

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