Volvo 850 GLT warm starting issue Topic is solved

TrevorVolvo · Post by **TrevorVolvo** » 06 Feb 2016, 13:07

My 1996 Volvo 850 GLT 5speed is having trouble starting after I let it sit for 30 minutes. It starts alright in the morning. It's losing fuel pressure at the rail when I have the key to position II. I have replaced the fuel pump and lots of other things. Not sure if this sounds like a fuel injector problem. If anyone has any ideas it would be greatly appreciated!

Post by **JDS60R** » 06 Feb 2016, 13:11

Lots of posts for you to search and enjoy

Start with the return valve at the pump - some folks just add one in and skip the process of dealing with the pump replacement.

Fuel regulator can be leaking into its vacuum source.

Fuel line can be leaking - Hopefully you would have smelled or seen that already.

Fuel injectors can be leaking. remove bolts, Pull the injectors and rail up together. Power up fuel pump by turning key to on ( not run) and inspect if injectors are leaking.

Others will chime in . I sold my last 2 850's over a year ago so others who have dealt with this recently will have more exacting advice.
They are such great cars. I really miss mine and may get another.

Post by **erikv11** » 06 Feb 2016, 14:15

Just to get the info into the thread as it may be relevant: have you changed or checked the fuel pump relay?

TrevorVolvo · Post by **TrevorVolvo** » 06 Feb 2016, 16:05

Thanks for your response. The fuel pump is brand new as of yesterday. I have yet to pull the injectors, do I need to replace the o rings if I pull them?
As for the fuel pump relay. Is there any way to test it? Or should I just swap it out?

Post by **cn90** » 06 Feb 2016, 16:34

Search forum for the jumper wire (with built-in fuse I posted a while back) that jumps between terminals 15 and 87. Next time you run into hard start problem, jump 15 and 87, if engine runs then fuel relay is bad.

On the issue of static fuel pressure, search forum for proper fuel pressure after ___ hours etc. Use a gauge and measure it at the fuel rail (undo the Schrader Valve cap first).

PS: The usual source of low residual fuel:
- Leaking fuel injector
- Bad check valve in fuel pump (what fuel pump do you use?)
- Bad fuel pressure regulator

TrevorVolvo · Post by **TrevorVolvo** » 06 Feb 2016, 17:42

I brought the car to my mechanic and he gave me the pump he had. It says Swedish parts online. We tested the fuel pressure when I was there and when i turned the key the fuel pressure went up and then started dropping slowly. Since I've put the new pump in I haven't tested the fuel pressure. But the problem still persists.
I can here the new pump turn on every time I turn the key. Would that rule out the relay?

TrevorVolvo · Post by **TrevorVolvo** » 06 Feb 2016, 17:44

Where is the fuel pressure regulator located?

Post by **erikv11** » 06 Feb 2016, 20:00

On your 96 GLT the FPR should be on the fuel rail, a cylinder-shaped unit that has a fuel line coming in and going out of it.

It's on the right here, on the clamped rubber line not the threaded metal line.

From underneath:

If the fuel rail has a disc with only no line in, no line out, that is not an FPR it is a damper. In that case the FPR is back under the passenger's feet.

TrevorVolvo · Post by **TrevorVolvo** » 07 Feb 2016, 18:10

Just to follow up I went to the junk yard and pulled a few injectors from a v70. Removed my injectors cleaned them all and replaced the ones that didn't look the best. The starting problem has been resolved, although I'm still not totally sure what the problem was. None of them were leaking, I guess maybe one was just faulty.
None the less this thread can be closed. Thank you for the help.

TrevorVolvo · Post by **TrevorVolvo** » 13 Feb 2016, 12:13

The injectors made it start good for about a day. Tried another set of injectors, and replaced o rings. Did the same thing. I want to replace the fuel pressure regulator but I only have a damper on the fuel rail and can't find the part I need. Fcp only has this one

: image.jpeg (37.84 KiB) Viewed 1515 times