1993 volvo 850 won't start

barteldp · Post by **barteldp** » 07 Feb 2013, 15:48

I'm working on a car, it was working it made it home. However now It won't start. I tried the to test the bicycle pump valve under the hood and almost nothing comes out. I tried the hot wire the relay to make sure the relay to the fuel pump wasn't bad, and it still didn't start. I am able to touch the relay and feel it click.

So I replaced the fuel pump, however that also did not seem to fix the issue.

I replaced the fuel filter, still no dice. The old fuel filter barely had anything in it.

The car turns over strong, but it doesn't seem like its getting fuel to the engine. when I crank the car and hold the pump it doesn't appear to be turning on.

I think the voltage might be incorrect going to the pump, however I'm not sure I'm testing that correctly. I am going to try again.

Any thoughts? I need to know what to test next

slimflex2 · Post by **slimflex2** » 08 Feb 2013, 00:30

are you getting spark?

barteldp · Post by **barteldp** » 08 Feb 2013, 10:08

sounds like it turns over pretty well.

The schraeder valve at the engine doesn't let out much gas just drops

How would I check spark?

Post by **erikv11** » 08 Feb 2013, 12:14

Your posts all match up with it not getting fuel.

I can't tell from your description if you have ruled out the fuel relay or not. Did you try removing the fuel relay and replacing it with a paperclip or a wire? That is the key test here.

If you did that and it doesn't fix it, the next thing is check for voltage at the pump, does it get 12v when you turn the key tpo position II? Also, can you hear the pump humming when you turn the key?

slimflex2 · Post by **slimflex2** » 08 Feb 2013, 13:06

barteldp wrote:sounds like it turns over pretty well.

The schraeder valve at the engine doesn't let out much gas just drops

How would I check spark?

this is what l suggest you do, get a gauge and check for the fuel pressure. it should be 39-40 psi on warm engine or 38-39 on a cold engine. if its lower than that, bam thats the problem. second check for spark by removing the cam cover and remove the spark plug wire on each cylinder, have someone try to start the car. you should see a spark on coming from the wire. if you dont see a spark, your wires need replacing. do this and get back to us. here is a link on how to check for fuel pressure.

barteldp · Post by **barteldp** » 09 Feb 2013, 17:41

okay, if its the fuel pressure what would I need to replace?

Post by **erikv11** » 09 Feb 2013, 22:37

If the fuel pressure is too low, then the places to check are the fuel system relay, the wiring to the fuel pump, the fuel pump itself, and the fuel pressure regulator. I wouldn't just replace stuff, I'd keep troubleshooting it like you were doing. There aren't many parts to look at here, you should definitely be able to track down the exact cause of low fuel pressure. If low pressure is the problem.

- Did you properly bypass the relay to test that (from your first post I think you did but I really can't tell)?
- Does the fuel pump hum when the key goes to position II? If it does, check fuel pressure immediately after that hum. Then check it shortly thereafter, maybe the FPR is leaking.
- Is there a strong smell of fuel in the vacuum line to the FPR (I don;t know where the FPR is on a 93)?
- How is the wiring to the fuel pump? Is the pump getting a full 12 volts back there? You'll need a cheap voltmeter to check that out.

Go through that stuff, I would expect you will find the problem. If the fuel pressure is low.

Post by **Ben850** » 10 Feb 2013, 07:46

While owning a '93, I am aware of ghosts in the machine. I thought the symptoms were fuel starvation as well. The obvious were being overlooked.
What year is on your Bougicord plug wires? Yes they must be Bougicord. I know now that brand new ones stopped a few issues that I was attributing to other things.
If they are the original '93 like mine were, they are likely arcing at many points.
The year is printed on the cables, so that is easy to check.

Luckily, I haven't had to dig into the fuel pump yet. I am not saying you are not getting an accurate assessment of your fuel pressure, but make sure the ignition system is rock solid on a '93.

Ofcourse do everything suggested in the above post as well.

loub · Post by **loub** » 10 Feb 2013, 09:32

When I was troubleshooting my 94 850 with a cranking:no start condition, I jumped the fuel pump 103 relay 15 and 87 socket positions. I got 12V at the fuel pump harness but I also gave a few shots of starting fluid spray into the intake snorkel: the engine ran for a few seconds confirming it was a fuel issue.