I have a 94 volvo 850 whose starter is cranking and turning the engine, but it is not starting. The battery is fine and I replaced the fuel filter, spark plugs, wires and distributor cap as it needed a tune-up anyway. My next logical guess is the fuel pump. I checked the diagnostic system under the hood for the injection and ignition systems and both came up "no fault detected", but I'm not sure what that rules out and what It doesn't.

Is there a good way to test if it is the fuel pump, and what else could it possibly be?

I tested the electrical with a lamp tester and the pump is getting power when the key is on. I also ran power directly to the pump and ran the lamp tester from the negative wire on the pump to ground and the lamp light up, showing that power is running through it. However, when power is running to the pump, it is not making any noise, it doesn't seem to be pumping. Does this mean that the pump isn't working, or does the car actually have to be running for the pump to be running? It doesn't seem to do anything even when cranking the engine.

 

Do you have fuel at the perge valve at the end of the rail?

Have you checked you CPS?

 

if its been cold outside.. do a simple test.
remove the fuel pump relay, leave it in the house at night, in the morning pop it back in and see if it starts.
If it does not, you can rule that out right away.

 

+1 with matt, didnt even think of climate..

 

it could just be fuel pump relay thats dead.. It could be that, even if its warm outside, that's harder to test.

 

Hey Mate,

sorry for hijacking your post but
funny enough I am having the same troubles with my V70, just got back from holidays, wanted to do a quick trip to the supermarket and.... nothing, same thing, cranking, full battery, has fuel in it, got the mechanic to have a look at it and he reckons it might be the immobiliser as the fuel pump an all fuel delivering parts are fine it runs on start ya bastard as long as you spray it in the manifold,as soon as you stop, it stops

 

Have you checked it to see if you have spark at the end of the ignition wires at the plug ??

As for the fuel pump. The pump "primes" as you first turn it on and start to crank the engine. It's about 3 seconds and it's just to get the fuel rail up to pressure so the engine can start. Once started the pump comes on full time. Sometimes this signal is oil pressure some times it comes from the engine management computer reading RPMs and when it sees the engine turning faster than the starter can crank it over.

See if you have spark and use a fuel pressure gauge on the fuel rail to see if you're getting fuel pressure from the pump.

 

Thank you everyone for the quick responses.

So I was wrong about a couple things - you can hear the pump priming when the key is in position 2 and when I depress the valve on the fuel rail after it's primed it squirts out fuel. so it seems there is fuel getting to the injetors and I believe the pump is working fine. I also jumped the fuel pump relay and it didn't change anything. Some stuff I read shows that it could be the fuel injector relay. Is there a way to jump or test this relay?

I haven't checked for spark yet, but I will the next time I get a chance.

Does anyone have any other ideas of what it could be, I've read bad idle air pump and bad flywheel sensor...i don't know what either of these are. Thanks!

 

Check for spark....
It could be your CPS

 

Are you really serious ?? You haven't even checked for the most basic things ,, fuel and spark but you're here asking for what's wrong?

You still don't know if you have spark but you want people to waste their time guessing what it might be? How about you do some simple things to help us .. help you.

If you can't be bothered to even do the basics, take it to a dealer or a repair shop or just replace your idle air pump as I'm sure it might be one of a couple thousand things that could be bad. That is if your car even has one as I'm "guessing" you haven't bothered to look for that either.

Get real.

 

Relax dude. I'm learning as I go. If you think your wasting your time don't respond. I only have a little spare time to work on it and I thought it was the pump so I didn't check the spark yet.

I just just checked and I am getting spark. I also checked the injection relay by just holding it while someone turned on the ignition and I felt it click. I think this means the relay works. My next guess is the cam position relay. Is there a good way to test this? Please don't answer if this question annoys you. A simple list of things to check would be really helpful and then I would stop bothering you guys

 

If you are getting spark it's not your cps. If that were bad you would NOT get spark. So you need to check fuel pressure to make sure the pump isn't supplying you with to little pressure, then check air. Maybe you have a bad MAF or something.