hi My 96 850R has about 128,000 miles. a few weeks ago it started stuttering when the engine warmed up. At the time this started the thermostat was stuck open and the car would only really get warmed up after 15 -20 minutes of driving or when in stop and go. When it was cold out getting on the freeway the temp gauge needle would drop from 3 to 4 because of the stuck thermostat.

I did change the thermostat and while the car does warm up normally
the symptoms have gotten progressively worse. The stutter is more frequent and the engine also dies.

When the stutter happens it doesn't feel like a misfire but rather it is momentarily cutting out. The car will cut out and die when comming to a stop. It will start right back up. and keep running. When pulling away from the stop it will cut out hard.

It will also occasionally cut out and die when driving but this doesn't happen as often. Again all of this happens when the engine is warm. If i get on the freeway when the car is cold and drive for a while it usually runs fine even after warming up. After getting off the freeway it will start doing it again.

It also seems to happen more after driving and shutting it down for a while. then driving again before the car cools off. I once let the car idle for while after driving for about 30 minutes and it began to idle rough even cutting out. At this point when pulling away from starts it would cut out.

Since then I brought it to a non volvo shop and they ran their computer. the code came up for a bad crank position sensor. They replaced the sensor but the problem came back when i drove it and the cel came on. I took it back to them and the code was agian for the Crank position sensor.

The mechanic said sometimes when a car cuts out if it does so suddenly it can set off code for the crank sensor the even that is not the cause of the propblem. he took it for a drive where he could get it to stutter and die.

Back at the shop he checked the fuel pressure and found that with the car off he would turn the key on and the pressure was about 36. he said with turning the key on and off the pressure would get up to about 40. With the car running the pressure was about 36. he kept the car running and would rev it high and hold the revs and it would run fine. He said there were no other codes. He said that while the pressure wasn't as high as it should be he didnt think it was low enough to cause the issues i was having.

Since then i replaced the fuel filter, air filter and changed to oil. I ran chevron through the tank. (with the old fuel filter still in).

i jumped the socket where the fuel pump relay plugs in and took it for a drive and it still had the problem. The oil filler cap was leaking I took the enging cover off and the top had a lot of oil in it. i dried it all up then pulled the plug wires at the bottom of the plug holes there was some sort of residue. (not much) it appeared old. I also took the dist cap off and inspected it and the rotor. while they looked a bit worn I didn't replace them.

in another act of desperation i took it to a local volvo shop. i told him what was going on and everything i had done and the other shop. i left it with him for two days and when i went back he said it set the crank position sensor code as well as the vehicle speed sensor code. i told him the speedometer would occaisionaly stop working recently then start back up.

I went back the next day and he put in a fuel pump relay and said to try driving it. Well after letting it warm up it started doing it again and after shutting it off and letting it sit for 10 minutes then getting back in stop and go traffic it started doing it agian.

Even dying when stopping. I did hear the fuel pump running when it died once. This was when it died when comming it to a quiet stop.

Before this occured i had recently replaced the heater core, starter and pcv system.

 

Well, it sounds like you may have a weak fuel pump. Fuel pressure should be 43 psi.

You should also consider replacing your wires, distributor, cap and rotor. How old are your wires? They have a date on them, week/year (29/96). If they are old, they may be failing under heat. It is possible that you are loosing spark when those parts get hot because they are old as dirt. Since you are having issues, I suggest you use only Volvo friendly parts.

 

a friend of mine referred me to a volvo dealer mechanic who also works on the side out of his house. I dropped the car off to him on saturday for a few hours. He ran the codes and of course the crank position sensor code popped up. he took it for a drive and got it to cut out several time even die.

The new crank position sensor isnt bosch its VDO brand like the gauges. he said he tested the sensor and seemed to be operating fine. His suggestion was for me to try and find someone who had a spare ecu to borrow and put it in my car to see if that fixes the problem. if not then start looking into the wiriing harness between the sensor and the ecu.

What are your thoughts on this? when the car stutters while driving sometimes the its soft and other times its a pretty good jerking motion. I was told that this could cause the crank sensor to misread. and through the code even when that is not the problem.

 

rspi thank you for the reply. a couple of questions. first what do you think about my second post and the suggestion to try and swap out the ecu? etc.

Second as far as your suggestion regarding the fuel pump I hate to keep throwing more parts in. I replaced the factory pump about 5 years ago. (not sure of exactly when). I put an insert in the existing housing the brand was airtex. Is there a way to narrow things down. and would you try this first before putting in a new distributor, rotor, plugs and possibly wires.

Also when you say volvo friendly parts locally the bosh rotor and distributor run about $100.00 for the bosch cap and rotor. plugs and wires are additional. plus spark plug wires about another hundred. are there any less expensive brands to use. If i knew this would cure the problem I would say fine. If they dont and i have to replace the fuel pump and then something else its all starting to add up fast.

Thank you

 

If the fuel pressure is low, that needs to be addressed. If the ignition parts are worn and old, they need to be replaced. The video suggest what brands I suggest/use.

If you had a REAL VOLVO mechanic look at it, he is likely more accurate as to what your problem is, especially since he has hands on where I am trying to translate what you are writing.

I was helping a lady that had similar issues with her S70. I also suspected her ECU and wiring to be issues. Her car wasn't as bad, just stumbled every once in a while.

 

Nope; they changed fuel pressure regulators in '96 and have same one through '98 S/V70 (ask me how i know..).

43.5 psi (@ idle) was correct spec up through '95 850 (N/A or turbo).


+1

 

If it's consistently throwing same sensor code then that's likely your problem, but that doesn't necessarily mean the sensor itself. Like your tech told you, could be the sensor, ECU, or wiring and connectors in between the two. If it were me, i would ck out the connectors at the ECU plugin and ohm out the wires from there to the sensor.

What code number is being set?

Based on your history and comments, likely not the fuel pump, but you're going to have to drive around with a fuel pressure gauge connected until the problem happens and see if the fuel pressure drops dramatically when it does.

BTW: (and it took me a long time to find this) for 1996-1998 LPT/HPT cars the fuel pressure spec is about 31 to 55 psi and both my cars sit at 36 psi at idle.

 

As for your tune up parts, you can check the prices at sites like www.iPdUSA.com or www.FCPEuro.com.

What kind of parts are you "throwing" at the car? No one here recommended that you "throw" parts at it. If the car is tossing a code telling you that your door know is causing the car to stall, I guess you need to replace or repair the door ****. If you have drivability issues and you have 18 year old ignition parts, it might be a good idea to replace those old a#% ignition parts. It's simply the COST of driving. Nobody wants to spend money for no reason but most people that drive do want their car running right.

It's called troubleshooting. Yes repair manuals do go down a list of things to check, test, and replace to track down issues. If your fuel pressure is good and your fuel pump is delivering steady pressure, don't replace it.

You have a few options here, keep stabbing at it yourself, drop it by a shop to stab at it until they repair or reject it, drop it by a dealer to poke at it until they repair it, or sell it for $800 and buy something else.

 

Low fuel pressure Well at least i think that based on a quick check. OK got a hold of a pressure gauge from autozone. Had a bunch of various connection ends but none of them would work. I even unbolted the throttle linkage and the vacuum fuel tree to see if i could get it screwed on to the schrader valve. but no luck. I decided just to attach a length of fuel line to the gauge and the schrader valve using clamps. I of course removed the actual shrader valve.

I had a few of the throttle linkage bolts in my hand and one slipped out and dropped into the exposed hole for the vacuum tree. will have to get it out with some sort of magnet before trying to start the car

 

So I tried doing a compression test without starting the car until i get the bolt out of the intake manifold/throttle body.

I did try it several times by turning the key to the on position and then shutting the key off. when doing this the pressure would initailly get up to almost 50 and then very quickly drop to 20 and then down to 12.

I did pull the vacuum line for the pressure regulator (where it attaches to the vacuum tree) there was no sign of fuel leakage. I will try again tomorrow after i remove the bolt.

Also the fuel pump tree felt slightly loose also the upper house on the idle control valve has hardend and felt a bit loose. i will try to remidy both items.

 

From experience, getting the fuel pressure tester onto the valve is a royal PITA. It's the schrader adapter that MANY vehicles use. In fact, I think it's the most common design used. You'll have to have the throttle linkage off of the manifold and out of the way to attach the connector.
The little, lone brass piece in the middle(not the one with the red cap) is what threads onto the valve on the rail, then the tester end threads onto it. Then you turn the ignition on and purge the tester with the little black button near the gauge. If the pressure reaches running pressure but falls then something isn't working right and fuel is leaking back into the tank out of the pressurized system.

 

hi everyone thanks for all of your help. this post would have been current as of the middle of last week say march 12,2014

i have done and have had done a lot of repairs to the car. when it first started hesitating and dying a few months ago. It was only doing it at after being fully warm and in traffic or stops.

Crank Sensor replaced my son who was driving the car most of the time took it to a shop as the check engine light was on. the code was P0336 or crankshaft sensor signal out of range. the sensor was replaced but did not solve the propblem

at that point i replaced the 1) fuel pump relay 2) fuel filter 3) changed the oil, filter and air filter

I put a fuel pump gauge on the car similar to the picture you posted and taped it to the windshiled. by then the car had graduated to hesitating even dying on the freeway. the fuel pump after starting and the car in idle would be around 39 pounds or so. under acceleration it would go up into the mid to high 40s. on the freeway when cruising with my foot lightly on the gas it would hang around 35 lbs or so.

when the car would cut out i would not see a drop in fuel pressure before hand.

after this i found a tear about 1 inch long in the intercooler house that connects to the throttle body. it was 98% thru not a complete cut. i changed the hose and removed and cleaned the throttle body.

After this the problem seemed to go away for a few days. then came back

since then I 1) changed the rest of the intercooler hoses 2) installed a new battery 3) install new ground wires - to from engine to chasis and 1 from battery to chasis.

at this point i noticed that the stft would rarely show the long term fuel trim which prior to this was running around negative 7 was no a very high positive number and the 02 sensor was moving in a very narrow range between 0.175 and 0.22. and the car was in open loop.

Since then i took it to a friend about and hour away from me who works at a volvo dealer. they let him work in their shop at night. for side jobs.

he did a smoke test and found a small leak (pinhole size) in the air intake tube between the maf and the turbo. he said its not big enough to cause my problems. He had another 96 there and swapped the follow items in and out without benifit. ECU, cam sensor, crank sensor, spark plug wires, and distributor.

He put in a new ect said the when he put a multi meter on it it was reading low and changed the 02 sensor.

He also tested the wiring between the crank sensor and the ecu and said it was tested fine though that doesnt mean it doesnt have a short.

He did try the maf from the other car and said it ran better but didnt think that was the problem.

I picked up the car and he hoped it was fine. I drove it home on the freeway and no problems. thought this is great.

the next morning my wife drove the car to work its about 2 miles from us. she drove up the block and made a right turn and said it hesitated then she drove about 1 mile ( two stop lights and two stop signs) stopped at a corner made the turn starting driving off and it hesitated and died.

i drove it for a couple of days. and after the car would warm up it would drive fine. then it started doing it all the time. it is basically undriveable at this point. it will die and hesitate constantly.

OH it always starts right back up.

One day last week it was hesitating every 20 feet or so. and was dying as well.

Did i mention it runs great in park or neutral. and you can rev it up and down. no problem.

Maf readings I think are OK. About 4 grams per second or about 14.4 kg/hr at idle in neutral or park. when you put it in drive they go up to 5.6 to grams per second. If i unplug the maf sensor and try to start the car. It starts up up idles rough and dies when you put it in gear.

its at the point where driving is dangerous.

About 8 months ago i replace the PCV or is it PVS. i also repalced the starter do to a no start condition (probably cylinoid) and the heater core.

fuel pump was replaced about 6 years ago (an insert) not volvo brand. i do hear it buzz each time im starting the car. it buzzes for more than 3 seconds then stops. it will buzz each time even if im just turning key on and off.

I cant get ahold of the person who did some of the resent work his grandma just had a stroke. He also says the car has him and his foremen who he solicitied help from stumped. he thinks I should try and shield the crank sensor cable. I have moved it all over the place to get it away from the coil and spark plug wires but it doesnt help.

He also suggested replacing the eniter electrical harness.

Im curious if it is electrical in the harness whey it will idle and rev totally fine.

any thoughts?

 

ok still having problems car has taken up a lot of money and time. If I added up all the money spent including car rentals while i tried to fix it. I would have been able to buy two of these in working order. ok maybe not but definately one.

The car is getting worse (it teased me over the weekend and stopped hesitating and dying after driving it very gently like a little old lady then successive runs on the freeway over a two day period i thought wow this is a lot better.) [B]However[B], on Monday it started hesitating and dying all over again.

On tuesday I drove it about 5 miles and had to pull over on the freeway as it kept stalling out. It would start right back up but then when pulling away it would hesitate and feeling like dying so i would stay on the side of the road. i waited a few minutes and gently pulled on the freeway and nursed it very easy back home. It acted different on the freeway. before it would the revs would drop by 500 rpms then maybe catch itself and if not die. this time it was three successive quick jerks and if i let off the gas it might be ok or it would die. While hesitating there were no dash lights comming on. only when it completely die would all the dash lights come on.

Today i drove it from across the street to in front of my house and parked it. I checked the connectors on the new ect and the electrical tape was comming loose. so I removed the tape and pulled the connectors apart cleaned them and put it back together. I then rin the car started it up and when i put it in Drive it died instantly. In Park it was fine. In Neutral fine. Only Drive did it die. and it did this several times.

I drove the car down the street in reverse and it ran fine. did a u turn in reverse it was fine. put it in Drive and instant death.

I let it sit about another 20 minutes. wondering if I now had a transmission issue as well. I tried restarting id t and ran thru the gears about 50 times. then i put it in drive and it was ok for a momemt then died. I tried again this time going in and out of neutral quickly a number of times. and it stayed running in drive longer. Next i put it in reverse and then in Drive and drove down the street to the corner about 300 feat. I stopped at the corner and it died. I restarted the car and backed it up the street and then put it in drive and parked it.

Some additional information. 1 i put in a used maf out of a 98 v70 (same part number) after the car is warm the maf numbers in neutral are lower about 3.6 to 3.9 G/s or 12.96kg/hr to 14.04 kg/hr

Fuel Pressure. left the guage on overnight and this morning before turning the key on it was 18lbs. when turning the key on it climbs to 49 then settled at 34 prior to starting. when started it climbed to 40 in park and higher when stepping on the gas. I did not drive it much today obviously. I did more testing on monday. and when it was fully warmed after driving about 20 - 30 minutes when i stopped it was about 39 in park. and when I shut off the engine it would climb to around 42 to 44. Also If i turned the key to on it would go to 49lbs then drop to around 42 or 44. after shutting the car off it would stay around 42 for a while before starting to drop.

Oh today i pulled the connection from the Maf then started the car. it ran worse and mostly wanted to die. it would run a bit in reverse then die and not at all in drive.

there is a small leak in the intake between the maf and the turbo i was told that it is the size of a pinhole and wouldnt cause my issues.

Also I sometimes hear a whooshing noise like air when shifting from neutral to reverse that sounds like its comming from the transmission.

oh and one more thing. the turbo gauge on the dash. at times the needle is fairly close to the left in Park about and 1/8 of an inch from the left and other times its further away maybe a quarter of an inch in Park. Also when I shift to Reverse or Drive it moves a but towards the center. There are times (i think when its running better but not totally sure) that its closer to the left.

 

I dont know if it matters the fuel pressure gauge Im using has no relieve valve. I had to remove the hose assembly it came with to fit it to the 850 along with a hose long enough to place on the windshiled. So i just have the one hose from gauge to shrader valve. and its hooked up with the valve removed.

 

Hi I was wondering if you ever figured this out and if you have taken the fuel pump out to inspect it?

 

I know this is old stuff. I have been dealing with exactly the same situation since buying our '97 T5 over a year ago. All the same items addressed, replaced, etc, including a different ECU. The car will only die when I get stuck in traffic on a "normal" or hot day. If it's chilly out, doesn't seem to happen. I have had it cut out once when I put the car in reverse! Seems like it's harness related--something getting jostled. I did have to fix the ECT pigtail and the system relay connector on the fan shroud, but those are fine now, and the problem continues. MAF, ECT, ECU, fuel pump, fuel pump relay, system relay, starter, cam sensor, crank sensor, all replaced. Probably more things I haven't thought of at the moment. Some gave incorrect readings and/or threw codes, others did not. Since replacing them, the problem continues, but no codes are stored at all. Just looking for new ideas from anyone! Thanks.

 

Check ground wires and their connection points, ground strap from the battery - look for corrosion both at the ends and for bubbling inside the wire.

 

Thanks. Have cleaned them all, but from the swap in our 855, I seem to recall there's a primary ground hidden under the right side headlight. Am I right about that? If so, maybe that's the one.