In my 1993 940 non-turbo wagon I have developed a new problem. When I first drive the car it runs like a charm no problems but after about 20-30 minutes it will start to spit and sputter and at times lose complete power and stall. It will always start right back up but eventually start sputtering again until cooled down.
I have been told that it might be the fuel pump relay but then told that the FP relay either works or it does not they don't slowly go out. I was then told maybe water in gas, I put in the water remover additive but still sputtering. Then I was told that it might be the fuel pump in the gas tank if it sputters only when under a half tank of gas because some 940's have two fuel pumps but mine only has one fuel pump. So I am looking for new suggestions. I will try anything. I did here that the distributer caps on my model start to make the car do funny things when not replaced so I will do that next. Has anyone heard that before?
I need help.

 

I am having a similiar problem when I first start up my Volvo 740 turbo when its cold engine. It will sputter for 10secs but not die. Tech said I should clean my throttle body and iac motor which i will do at a later date.

 

I've had that exact problem a few months...just fixed (finally!) it by replacing the spark plugs...again.

I had put Bosch Platinum's in around labor day, and the problem started soon after. Now I'm running Bosch Copper, and it seems OK so far (two days, but with single digit ambient temps)

 

GaryBrad: There is a lot of things it could be. The fuel pump relay would cause that. Check on the relay and see what date is stamped on it. It could also be a bad power stage. Located on the inside of the left side fender.It is mounted on a peice of aluminum.

It could also be the Dist.

Do you have a Regina or Bosch system?

Regina= Square coil
Bosch=Round coil

 

Small cracks in the distributor cap can make the car sputter. Pull the cap off and check for carbon tracks along the inside of the cap.

 

Thanks Guys
Well, since we spoke last my computer HD crashed and I just got that fixed so I'm back. Here is the latest. I have since found a small crack on the bottom of a vacume hose that when fixed solved some of the problems but it then started sputtering again and finally completely shut down on a major road at rush hour on Friday and I was about to rip my hair out. Luckly it was across the street from a volvo dealer. Some how I got it started and limped to the side of the road, walked across the street and purchased a fuel pump relay, distributer cap and rotor. She started right up but later started to spit again. I am convinced it is some type of short in my wiring. The only other thing it could be is the power stage unite or a wiring short. Thanks for all the info, this site rocks.

 

Have you checked the coil? It's not often that they go bad, but it has happened to me with both Honda and GM products.

 

Thanks Mick
I have not checked the coil but I sure have been thinking about it being the problem. Tech asked me earlier about what kind it was and I forgot to answer him but it is a Regina coil system because it is square. That was another item I asked about early on and I was told that coils do not go bad intermitently. They say they either work or don't. You never know.
Thanks Gary

 

Not necessarily. I've had rough running problems after the car was warmed up. Driving normally and then all of a sudden, loss of power, heavy missing, then a complete recovery. It was intermittent and went on for some time. I spent a lot of time and money replacing stuff only to have the problem re-occur. Finally chenged the coil as a last resort and Viola! Problem solved.

 

Wow, that is great news about the coil. I will try the coil next because I want the problem to be something that I can just change and make go away. At this point price doesn't even bother me. I hate problems that do not happen all the time to let you diagnose them while the car is in the driveway. Oh well I know that I am not wasting my money replaceing some of these items because they will all need it eventually. When I do replace my coil what should I replace it with, the same as what I have or something different? Thanks again Micklas.

 

The fact that it starts after it has warmed up makes me think it is the hall pickup sensor or speed sensor located behind the head on the bellhousing. Look at the insulation and see if it is cracked. your tach will immediately drop to zero if this is what is causing it. It could also be the ignition module on the drivers side fender but I doubt it because you are having the trouble when it heats up.

 

Replace it with whatever you can acquire that meets factory specs.