So, about 2 weeks ago my 850 stalled out on me while idling at a red light. I recently had a mechanic friend of mine look at it. He found that the Fuel Pressure Regulator was compromised and it was spitting gasoline directly into the air intake. After this discovery, we pulled the fuel pump relay, spark plugs, and turned the motor over to expel the gasoline from the spark plug cylinders. today we sucked the gasoline out of the air intake. There was probably about 12-16oz of gasoline in there. Right now the engine turns over just fine. It doesnt sound like any real damage was done to the rods, pistons, etc, but it still won't start. Any help, or suggestions would be great!

 

did you measure the fuel pressure at the rail after your repairs? After that I'd check for spark just to be sure its there. Next consider doing a compression test - including a wet compression test. Its quite possible the extra fuel washed all the oil off the cylinder sleeves so you are down on compression. The wet test (or simply adding a small amount of oil to the cylinders) will recover that and will show you if you've actually damaged the engine.

 

My mechanic buddy actually recommended doing the wet compression test. I wanted to check for spark, but there was gasoline everywhere, so i didnt feel safe doing it until some of it evaporated. Right now it's sitting and hopefully drying out the intake as well. Thanks for the advice. My buddy is fairly certain that the engine will be fine, but we won't know until it's running.

 

Put a small amount of oil in each cylinder, replace all plugs, and she should start right up.

 

Also after it is together, if it still won't start spray a 1 or 2 second burst of starting fluid into the air intake then try to start it. If it fires and runs for a couple seconds then you have a fuel delivery issue. If it does not fire then you likely have a spark issue.

 

Thanks for the help guys. We got it running after doing a lot of cranking. I guess there was more fuel in the intake than we had thought. So it's running and driving now, but it's sputtering a lot when I'm driving in low RPMs and at about 3k, it kinda kicks into having normal power and drives smoothly. I changed the plugs out and it's still acting up.

 

I'd start with a check for air leaks, then clean the MAF, idle air control valve and throttle body. I'm wondering if any fuel got on the MAF. Have you measured the fuel pressure at the rail since you installed the new regulator?

 

Ok, I will ask....is the check engine light on? If so, read the codes and report back. It will help pinpoint the misfire issue.

 

The check engine light isn't on. I haven't measured the fuel pressure coming from the rail. I'm not sure how to do that.

 

you can probably rent or buy a fuel pressure gauge from an Autozone or similar. Here's a vid on youtube for measuring. Check Volvotips.com or a manual for the target pressure on the 850s.

 

Thanks a lot. If there's any other possibilities, I'd greatly appreciate it

 

FWIW, I don't have an angle fitting that will fit on there. I just mention that so that if you buy a fuel pressure guage, don't expect it'll just fit. I have run into that same problem on several cars, where the fuel pressure fitting was made in such a way that a guage couldn't be connected. The Schrader valve Volvo used is the same as a tire, though, so that opens up some possibilities. You just need something that has a very small right angle on the attachment end. I notice the guy in the video managed without that.