on the way to coffee and started right up....got about 4 blocks down the road and it suddenly acted like it was out of fuel and studdered and quit. Prior to that, this ran great with no hessitation, or idle issues. i know it's either, fuel or ignition,due to some possible electronic malfunction....from what i'm reading, could be the cam position sensor or maf sensor or the fuel pump itself. I can hear the hum of the fuel pump initially when i turn the key on...about 4 or 5 seconds before the faint hum stops....so i assume the pump is functioning. i'm trying to get an idea of what's likely the problem. engine turns over with no unusual sounds, it just doesn't start! the car is in great shape outside and inside and i've put 60 k on it in past 4 years with NO problems!

 

here's an update on this issue....this is a na 850glt......in damn fine shape!
i visually checked fuel rail pressure and it was weak...barely dribbled out...certainly no spray that 40 pounds would cause...i disconnected the air intake off the air filter housing and sprayed some starter fluid into the hose...attached it back in position and the car started immeidately....stumbled and missed a couple of times but did run for about a minute....and ran just like before this whole stopped and would not start again...i deduct there is a fuel issue here but what can cause this other than a faulty pump? when i turn on the key and listen, i can hear the pump running for about 5 seconds before it shuts off [key is on position but engine not running] where is the fuel filter on this model? other suggestions? houghts?

 

It is definitely a fuel issue. It could be one of three things. The fuel pressure regulator, the fuel pump or the fuel pump relay. I would check the relay first by jumping the leads. Then check out the regulator and if all else fails, then do the pump.

 

Ck out this thread:
https://volvoforums.com/forum/showth...el+pump+hammer

Try the hammer trick to see if the pump reacts/works when tapped on. If it does, you found your problem.

 

thanks for your suggestions...i guess my question here is, "is there anything that would tell the pump not to run? after i physically get to the pump in the trunk, i just want to be sure that there is not an electronic device through a malfunction, telling the pump not to run. as i mentioned, i can sit in the car and turn the key on and hear the slight hum of the pump building up pressure for about 5 seconds and then it shuts off [because the motor isn't running]that would eliminate the relay being an issue to my way of thinking. also, if the filter was clogged, my exeperience tells me that over night a clogged filter would allow some fuel seepage which in turn would allow a slight fire up before shutting off...i got no hint of fire up prior to spraying the starter fluid into the intake. is my logic here sound?

 

also, where physically is the fuel regulator located for checking? is in the pump area?

 

OK, yeah i see where you're going; thinking it's one of following things:

1. Clogged fuel filter
2. Bad fuel pump relay
3. Bad fuel pump
4. Some possible combo (can't rule this out!)
5. Some sensor is telling the ECM to turn off the fuel pump.

1. First off, if you've never replaced the fuel filter in last 4 yrs, it's due; just do it. If that fixes your problem, you're done. If you want to verify, get a fuel pressure gauge and ck it.
2. In post #2 of link in my above post, there's another link on how to ck the fuel pump relay; simple to do and you may find broken solder joints.
3. If you suspect something may be shutting off electrical pwr to the pump, then pop the access cover off and throw a volt meter across the pump leads. Once the cover is off you should be able to clearly hear if the pump is running or not; if you have voltage to the pump wires and the pump's not running, then pump is bad. If you see the voltage (approx 12v) to the pump go away, then that's number 5; report back if you see this.

Report back anyway and let us know what you find.

Oh yeah; the fuel pressure regulator is right there on the fuel rail. Pull the vacuum line off of it and see if there's fuel in it; if so, regulator is bad.

 

+ Hearing the pump run when you turn the key doesn't mean it's actually pumping. You gotta check pressure. My FP relay went bad. I could hear my pump too, but when I turned the key to start and cranked it over the relay would fail and the pump would quit. What a pain! My two cents.