I've had this problem for a while now and I cannot figure it out. My 1994 940 Turbo wagon starts & idles fine, but when you try to give it any gas it spits, sputters & sometimes shuts off. I've replaced the fuel pumps, FPR, TPS with no change is this. Please help. It's a great car but it useless to me if I can't drive it.

 

check the intake air path between the turbo and intake manifold for any leaks. the big silicone rubber tube that comes off the turbo and into the intercooler is a prime suspect.

 

Check to see if there are any engine codes being thrown.

 

Almost certainly a vacuum leak of sorts. Here's a few places to check:
- PCV hoses/seals/valves
- Oil dipstick O-rings
- Engine oil cap o-ring
- IACV Hoses and/or the valve itself (It seems like your IACV is working because your car idles fine?).
- EVAP hoses and/or canister
- Gas cap (Its all connected to the EVAP system)
- Fuel tank vapor hose connection


Good luck!

 

thank you all for the suggestions! Would the vacuum leak show up if I connect a vacuum gauge to the system? And what kind of numbers should I be looking for on that gauge?

 

A Vacuum gauge should read around 18-22 inches of mercury, but this won't show you much, if anything about vacuum leaks.


To find leaks, your best bet is to smoke out your intake system. I'm not a fan of spraying carb cleaner all over the place with a running engine as most of the internet suggests. Something just doesn't sit right with me when people tell you to spray flammable liquid onto a moving engine.


You might also be able to use a bike pump and lightly pressurize the intake system through one of the intake manifold ports, with the engine off. If your leak is bad enough, you'll hear hissing very quickly. Note that the evap system would still need to be checked if you don't find anything at the engine.

 

Check you Mass Air Flow sensor. I have a non-turbo 240, but I was having similar issues, particularly when the car was cold. I cleaned the MAF and now it runs great. Took about 5 minutes.

 

+1, mafs

 

one test for a bad MAF is, with the car off, unplug the MAF, then start the car. it will drive with limp power, but it should drive. it will light the check engine light and throw a code, that the MAF is AWOL. switch off the engine, before plugging it back in, then clear the code...

cleaning MAF's only works sometimes. yours sounds to me like its electrically fried. If you do decide to try cleaning it, get some MAF Cleaner spray from CRC or whatever, remove it entirely from the car, hold it sideways at an angle, with the electronics module on top, and spray the cleaner at the center hot wire assembly, so it runs out the other end. idea is you don't want the cleaner to run inside the electronics module. let it dry before reinstalling.

sadly, there are no 'new' original Bosch MAFs for these cars, only rebuilt ones, and the rebuilt ones are of varying quality. I have gotten good rebuilds from volvo-specific indie mechanics who've found ones that work. used to be the Bosch factory rebuilt ones were good, but I'm not sure I trust those anymore. I believe Volvo is selling Chinese made MAF's now.

 

Pierce would PCB electronic contact cleaner work o.k.? What I use on my guitar amps to clean dust, and pots. I'm guessing it's the same stuff, mild. I've got a similar issue with my Regina, but it's low idle, my guess is MAF, runs great at higher RPMs.

 

contact cleaner leaves a little oil behind, bad juju on the MAF

regina doesn't HAVE an MAF, it uses a manifold air pressure (MAP) sensor, and throttle position potentiometer, instead.