My 96 850 was running great, was turning around in the driveway and it just cuts off. Starter spun the engine but no running. Checked fuel injectors they are operating and the ignition is powering the sparkplugs. Had fuel squirt out the test port when schrader valve depressed. Sparkplugs were slightly rich looking. Decided to pull #2 fuse, labeled fuel pump, thinking if a bit flooded spinning the engine over would help clear excess fuel , however, the engine fired up, RPM's 2500 and it sounded like it was running rich. Was able to move it out of the middle of the driveway. Engine died instant # 2 fuse reinstalled. What am I missing? I am open your knowledge as to items to check.

 

Start by measuring the fuel pressure at the rail (with the fuse in) - it should be about 43 PSI.

Here's a good post regarding testing the pressure regulator etc.

https://volvoforums.com/forum/volvo-...problem-61203/

 

Thank you for your response. Checked the fuel pressure, had a reading of app. 45 psi, maintained 40 psi when key off. Vehicle actually ran even with air idle control valve hose off. Had to remove the air idle valve to check pressure not having a 90 deg. fitting. put everything back together and vehicle ran perfectly till it warmed up ,app. 4-5 minutes later. Idle raced to app. 2500 RPM and then died when vehicle was put in gear. Does not want to restart at this time. Cleaned the 3 grounds to the engine and the small ground at the new battery as well as the small positive at the battery.

 

i would think you'd be seeing a code for fuel trim or MAF or something. I think it would be worthwhile to see if it'll run with the MAF unplugged (that's free). But a bad MAF might not get your idle that high. I am not sure how high the IAC can really take it.

you need some air to get in there somehow to get the engine running at 2500 rpm. There are a lot of places where you could have a large vacuum leak on that engine, and it's at an age where you wouldn't be too shocked to see one.

 

Ok, ran scan on engine system, used an Autel MD 808Pro, had P0123 code stored, TPS reading high. Cleared code. Was able to start vehicle no problem, idle was normal and was able increase RPM no problem. Vehicle was running rich, didn't run any PIDS, just the smell test. Also didn't want to cause plug fouling, so operated engine for less than 2 minutes. Rechecked for any codes, P0123 was recorded again. Have a TPS, Bosch, on order arriving next week. Will be out of town helping my partner with her cancer treatment and will update when I return in a couple of weeks. Thanks for the help.

 

Had this in the "archives" from when I had my 850T..

 

Thank you for the help. This car's condition, mechanically and cosmetically, is too good not do what is needed for it to have much longer life. I'm old school and don't really care for all the 'nannies' found on the newer cars. Those seem to be needed for those 'operators' who think sitting in the driver's seat is all that is needed to be considered a driver/operator.