1995 Volvo 850 Turbo running rough , hard to start

STIFFSQUID · Post by **STIFFSQUID** » 27 Dec 2008, 18:25

Hello, Hope someone can help. The car has been really hard to start lately. I can get it started but have to put my foot in it, and have to keep it in it for a while.It will finally idle but runs rough and surges. A little history, the wife had the bottom line to the radiater pop off, and ran it out of oil. She pulled over right away, but not soon enough to burn out the Turbo.I replaced the turbo and it ran fine. This was a couple of months ago. Now with this cold weather the car is acting up. I replaced the fuel pump and put new Plugs in, but still the same results. Any help would be appreciated.

Post by **MadeInJapan** » 27 Dec 2008, 21:26

Welcome to MVS.
I would need more information to help with diagnosing your problem. It is also hard to tell if your earlier oil line problem is related to what's going on now or not. What you describe could be from a multitude of different issues. I suppose, tackling the cheap stuff first would be best- check plug gaps..should be 0.028 as the widest, down to 0.026 inches at the lowest- also our cars don't like expensive Platinum plugs- make sure they are just the cheap copper core Bosch or actual Volvo turbo plugs. If this is taken care of, then check for vacuum leaks- especially those around the sides of the intake manifold and under the throttle plate. Your description with hard cranking if spark and fuel are no issue could be related to a vacuum or vacuum leak(s).

Post by **Ozark Lee** » 27 Dec 2008, 21:30

Wow,

Running the motor out of oil to the point where it eats the turbo is a bad thing but let's assume that the bottom end of the motor isn't toast. Have you checked the fuel pressure with the key in position II. A bad fuel pump relay could cause the problems you describe. The fuel pressure should be stable at around 44 PSI.

A bad check valve in the fuel pump housing would also cause hard starts so you also need to look at the fuel pressure when you turn the key back off to see if it quickly drops to zero. It should hold most of its pressure over several minutes.

...Lee

STIFFSQUID · Post by **STIFFSQUID** » 27 Dec 2008, 23:23

Thanks guys., I'll be checking the codes in the morning.

carp-guru · Post by **carp-guru** » 28 Dec 2008, 04:48

I would pull the codes out of it. I would hope to see a temp sensor fault or something along those lines. It could be giving the engine managment system a false reading.

Look at your induction hoses especially those on the turbo to see if anything has come off.

Clean the throttle body, and the IAC Valve , and access from there.

STIFFSQUID · Post by **STIFFSQUID** » 28 Dec 2008, 12:07

Here we go, alot of codes, 315,435,543,452,542,231,451,545,551,552,544,454,554. Just reset , and Im going to look these up. If anyone knows off the bat,.At this point I want to get it running and probably take it in for a tune up.The car has 201,000 miles on it. It started this morning, ran for a while, roughly, then died in the drive. Now battery seems weak, but its a new one.

STIFFSQUID · Post by **STIFFSQUID** » 28 Dec 2008, 12:17

Well it looks like a lot of misfiring. Wonder when the turbo went, it fouled up the cat converter.

STIFFSQUID · Post by **STIFFSQUID** » 29 Dec 2008, 18:28

I replaced the cap and rotor today and it fired right up.The old cap had oil in it .Maybe the seal around the cap of the rotor went and let oil through which affected the firing.Replaced them and the car seems to idle fine. Thanks to all who commented.