I'm at my wits end with this car, I don't know what else to do.

I replaced the fuel pump, the battery, mass air flow sensor, cleaned the throttle body, cleaned the air intake control valve. I also found a vacuum leak and repaired it. I checked the engine code and it says that the problem is the mass air flow sensor, but I replaced it and still nothing. The only other thing I could think of is replacing the fuel filter, but I'm not getting a code for that.

If anybody could give some advice I'd really appreciate it.
Mileage - 165,xxx

 

Spark plugs? Wires? You have an engine misfire! Take a compression test, if all is well, tune the car up!

 

If that's a Bosch, it will have two fuel pumps, one in tank, one outside.

You should definitely replace that fuel filter if you haven't done so recently.

Also, fuel pump relay?

 

You definitely need not worry about the fuel relay, the fuel pumps or the fuel filter, given your set of symptoms. What you describe is not fuel starvation...

 

Trip, does this seem like your problem? Engine Tune and Performance

Lev, do you have any ideas what's causing my idle problems? https://volvoforums.com/forum/volvo-...g-crazy-76174/

 

Lev, the spark plugs and wires were replaced about 8 months ago, but I've probably only driven it about 3,000 miles since then. So they haven't really been worn out too much. Maybe there's a problem with the distributor though?

Dnarby, it sounds similar but not entirely the same. When mine dies, it will be as though completely lost power, but the lights are still on. When I try an start it again, it will turn over, but it won't engage. Usually the only way to get it going again is either leaving it for a few hours, or using a bit of starter fluid.

 

You say you idle ROUGH? That's usually a misfire. Why? Eliminate the big things, head gasket, burned valves, etc. with a compression test. If the compression is OK then address the minor possibilities of a misfire such as a tune up items, also CPS, Power Stage, distributor, etc. Then, what parts brands are you using? Many problems today are caused by low quality aftermarket parts. Wires Bougicords? Plugs NGKs? MAFS Bosch? Volvo problems are very often the simplest things and often the owner goes about the problem by throwing parts at the car without first good diagnosis. And with every part replaced, if it is substandard, it introduces a new element into the puzzle...

 

What lev said, compression test rules out a lot.

That link I posted said: (engine suddenly has absolutely no power, but the dash lights do not come on)

So if your brick loses power, but the dash lights don't come on (car isn't running, but ignition is on), that is the same symptom they are describing.

Thing is, I'm pretty sure your brick has a crank position sensor, not a hall sensor. But I wouldn't be surprised if they present the same when failing (crank sensors often get intermittent before failing). Good news is that's not to hard to replace.

 

Sounds like a bad crank position sensor to me. It is located on the top of the bell housing where the engine and tranney meet. It has a thick black wire that goes to a connector on the firewall. If the insulation is cracked and flaking off, it most likely needs a replacement. They tend to fail intermittently causing occasional stalling.

 

The problem is your shotgunning parts. I've yet to read one valid test you've done to determine what good or bad minus the vacuum leak repair.

 

Check for more vacuum leaks. I had similar problems with my '91 940, only to realize it was vaccuum leaks everywhere. Also check your fuel pressure regulator and connections. Tighten all your hose clamps, and especially check the hoses coming from the PCV and oil trap. On my car, they were easily removed by hand. I ended up putting a clamp on them and it fixed my problems.