So my 1995 850 has this hot start problem. After reading various forums, I suspect the fuel relay may need to be replaced. I heard the trick about putting a paper clip between socket 15 and 87 to bypass the fuel rely and diagnose the problem. The thing is on my relay I have sockets 15, 31, 31b, 87a, 87b it looks just like this VOLVO 850 1993-1997 FUEL PUMP RELAY, NON-TURBO 9441029

So question is do I use socket 87a or 87b?

Thanks.

 

Do you hear the fuel pump cycle on when you turn the key to position II?

 

I don't know, I hear kind of a humming noise which sounds like a fan. Is that it?

 

Yes. Your fuel pump relay is probably OK.

Could you post your symptoms and what you have checked so far?

 

Just did this this morning - i needed to pumped some gas out.
Jump between 15 (top center) and 87a (bottom center) with the key on.

PDF Explaining this

 

Thank you! exactly what I was looking for. I hope this will solve the problem!

 

Basically, the car starts up fine in the morning and when it is cold. After warming up, it can give me some trouble starting, and will sometimes start after a few tries and a little bit of waiting. Sometimes I need to wait a half an hour or more for the car to start after doing a errand or so. It used to turn over really good and not fire up. Now it seems to be getting progressively worse. When it is warm it will sometimes turn over a little bit then I just hear the fan type of noise. Sometimes it will shake a little or thud.

I made another thread about how this car also has an oil leak so I am wondering if it might have an engine valve leak but so far it it runs well and the temperature gauge reads normal. The oil come out the cap and the bottom and there is a little smoke that comes out the tail after idling.

I don't think I am up for a lot of expensive fixes on this car, I am about ready to throw in the towel. But I was reading the hot start problem could be fuel pump relay or cam position sensor among other things that are not too expensive. I would like to keep it running a little longer with out investing too much.

 

Just adding that even though a fuel pump runs when you turn on the key does not mean it is pressurizing the system. Keep that in mind. You should always test the pressure at the rail.

Honestly in this situation, if it were me I would have gone for the rail pressure first. That will tell you three things. Whether or not the pump is working and if there is pressure enough to run the injectors and if your fuel system is ok.

 

Yeah, you are jumping to a conclusion without checking the symptoms.

In my opinion, the first things to check in this order: Fuel pressure, spark plugs, fuel pressure regulator/or leaking injector(s), coolant temp sensor.

It would help if you could pull a spark plug just after you have this problem, and see if it is saturated with fuel.

A bad cam position sensor *shouldn't* only be giving you a problem on hot starts. It would be more of a "intermittent shuts off and won't start up" sort of a problem. And you should have a trouble code (check engine light aka CEL). Is your CEL on?

 

no check engine light is not on. Interestingly enough when this first started it did have some problems sputtering and stalling. It would sometimes start and then stall. That was several months ago. But that problem went away and now this has been going on.

 

I was just letting him know how to properly power the pump. You obivously check the rail pressure, filter, etc....

 

I bought a wagon that had a fuel problem. Watch my video of what was happening. The car would start then die. Watch the fuel pressure gauge.

Fuel Pressure

 

Just wanted to update this thread. I took it to the shop and it ended up being a bad started. Sear auto guys told me that without even looking at it when I went in for some fluid exchange and I thought they didn't know what they were talking about. Had the starter replaced and problem solved.

I am starting to love my old 1995 850. I have thought about throwing in the towel so many times, but she always comes back to life.

 

....was it not turning over once the car was at operating temp?

That would have been a vital bit of information for us here to help ya. :P

 

It used to turn over just fine, but not start. But then after time it got to the point that it would not turn over as much. That is why I though the starter was OK, it only happened when hot and used to be good at turning over. I am not very knowledgeable about cars really, that's why I came to you guys!

 

Or you many still have a problem with the hard starting and all the turning over without it starting is what wore out the starter and will do the same to the new one

 

I was also thinking that maybe this problem wore out the starter. But now it seems to start right up with no problem. Before it used to turn over and turn over with out starting. Now it is just like normal. I guess its wait and see if any more problems come up. So far, so good.

 

Some one on another thread I'm following mentioned that they had similar problem that they also fixed with a new starter.

They said basically the old starter was not cranking fast enough for the electronic ignition to work properly.

 

I've also heard it said that when starters start to go bad, they need optimum conditions to work properly, so maybe that explains the starting fine when cold, but not when hot?

I've been driving around with the new starter for a week now and I have not had any problems at all, so it looks like this was the only thing related to this as far as I can tell.

 

Life is good !!!