97, 850 turbo, stalling, not starting, many fault codes

[Crotext]

Hello to all I am still learning and new to working on Volvos. My 850 had an oil leak so I repaired the Turbo cooler lines after a good deal of effort. I got good info from this group in how to do it and I am appreciative for that.

However, just before I took it apart for the oil fix, it started stalling and would be hard to start. I noticed it would start after flooring the pedal and got me home two times. Now I have finished the oil line repair and while it sits on jacks, I wanted to start it for a leak check. It will fire but not start so I assume it is fuel related.

I ran OBD codes from the main socket by the shift stick, and see PO 442, PO 410, PO 300, PO 301, PO133, PO 103, PO 131, PO 243, and last but not least, PO 172. I almost fell over at the number of fault codes that popped up. The first one above, has shown for a few months and I am thinking it is related to dripping when I fill the gas tank and will be dealt with later. Is there any other single sensor or part failing that would cause all these read outs? Can it be a loose single wire or vacuum line causing the problem and would it give me this many codes?

I appreciate any and all help or suggestions.

[FCPEURO]

If the car is not getting fuel, then it could be one of three things. The fuel pressure regulator, the fuel pump, or the fuel pump relay. I would check all three starting with the relay to make sure they are all in working order. More then likely, one of them are bad.

[Johnny78Blaze]

New fuel filter, clean up the injectors real good as well? In my travels I haven't had any problems with the relay. You can get a decent and inexpensive fuel pressure tester on amazon.com for about $42. I believe it's an Actron brand....professional kit. I'm springing for one this week as I'm having some 'issues'. The tester would be great though for checking your pressure numbers on the pump, regulator, etc.

[shiloh51933]

Doesn't sound good kid, if your having fuel issues and it won't start then a fuel pressure gauge kit is kinda usless. If you can get her to run then you can copp a good fuel pressure tester kit at Harbor Freight for much less, I just got 1 for around 20 bucks. Have checked your ignition system yet? Plugs, wires, coil, cap/rotor or what ever. If your getting good spark then I'd start checking fuel system.

[Crotext]

I had a helper turn the key on while I touched the main relay after I pulled it and re-inserted, ,,,it clicked. Then same while listening to the pump and it was whining. Then I checked for pressure at the rail valve and it squirted with more pressure than I expected. I have seen more and much older posts here where a problem was found with the wiring of the "gray relay"
mounted on the radiator shroud. It was never explained, what wiring it is they are talking about as being "cold welded" and coming loose. Do I have to remove the plastic cap from the relay or is it the outside connector wires that are troublesome?
All too often we see how it was fixed in text here, but still don't have a clue what the problem was. I cannot afford to invest a small fortune in tools and test equipment to fix a car that is going to market soon. Thanks alot for any explanations or input.

Oh by the way, it does fire but just won't start. It gets to the almost stage then gives up so I assumed it was a fuel issue.
I know now the fuel is at the end of the rail with pressure.

[baffled]

You sent me a PM and I tried to reply to it but I'm not sure if it went through. You asked me which relay had the cold solder joints on my car. It was the fuel pump relay and it is in a container under the hood up by the windshield on the driver's side. The fellow who took the relay apart to inspect it rather than trying to jump it for voltage as he said it was easier to check after it was taken out. Also, on my 1994 - 850, the relay is green in color but apparently on different years they can be white. I don't know if this is what is causing your problems but after re-soldering 5 joints in mine, so far the problem is solved. I hope this helps clear up your question.

[Crotext]

Thanks for the reply. I have a new relay on the way for both the pumpo and injectors, in addition to a MAF sensor.\
I bought them cheap enough to risk it. I have to re-read your posts but was your car stalling and not starting at times?

Anyone know if an O2 sensor could cause the stalling and not starting? I have replaced those before on non-turbo engines
after having some sputtering problems but then the Code reads were very specific unlike what I am getting now.

[rspi]

As for the multiple codes, that happened to me once when I ran my car out of gas. I actually wasn't out of gas but real low and sitting in front of a friends house talking and the pump couldn't pick up the gas in the tank. I had about 8 codes. Got gas and was fine. So, as to your codes, I think your car ran out of gas, likely due to the pump being off.

My guess would be that you have a fuel pump relay going out. Those things can be pretty intermittant which drives people nuts. I actually picked up a few spare from a salvage yard. You can be driving and start spuddering and stall. Sometimes the car will start right up and sometimes it takes a few minutes. I'm at the point to say that the relay should be a maintenance item and be replaced every 10 years. I also believe that the relay causing power surges on the pump will likely damage the pump over time. So making it a maintenace item may help your fuel pump last longer.

I really don't think a bad o2 sensor can cause your car to not start or stall. I know of people that drive for years with bad o2 sensors. The fuel relay near your fan is the injector relay. As for the MAF. If you don't have a code (cel) for that, it's likely fine.

[shiloh51933]

Any body have any pics of the fuel pump relay for everybody to see? I don't have any myself on hand since I was into that area. My relay was the green colored fuel pump relay(96 850GLT).

[rspi]

103 in this pic: http://www.atthetipwebs.com/technologyi ... CT2630.JPG