850R No Spark

[scot850]

If there is:

1) No sound at the pump when ignition is turned to II
2) No fuel pressure at the Schraeder valve at the injector line.
3) You are certain the fuel pump fuse is good
4) The fuel pump relay is 100% good

Then it is likely as Misha said, it is either the fuel pump has failed or it is not getting power to the pump. If the car has been sitting for some time, mice or rodents may have chewed the wiring on top of the tank.

I am not an electrical genius like some here, but I would be looking for 12V at the fuel pump to start wit and then work from there. If you have 12V then it is more likely the fuel pump has failed. At least is is accessible from under the floor in a FWD car.

Good Luck!

Neil.

[e13h]

If there is:

1) No sound at the pump when ignition is turned to II
2) No fuel pressure at the Schraeder valve at the injector line.
3) You are certain the fuel pump fuse is good
4) The fuel pump relay is 100% good

Then it is likely as Misha said, it is either the fuel pump has failed or it is not getting power to the pump. If the car has been sitting for some time, mice or rodents may have chewed the wiring on top of the tank.

I am not an electrical genius like some here, but I would be looking for 12V at the fuel pump to start wit and then work from there. If you have 12V then it is more likely the fuel pump has failed. At least is is accessible from under the floor in a FWD car.

Good Luck!

Neil.

Not terribly worried about the fuel issue, the wiring seems fine on the pump as I pulled it out to see if it looked original. The spark problem has been what is eluding me these past two weeks or so.

[erikv11]

Sorry to beat a dead horse but no spark as in zero spark, ever, plugs don't give a spark to the block right? Just confused by why you changed the plugs for a no-spark, want to make sure I am on the same page.

When you say you "checked cam sensor and crank sensor" does that mean swapped in known good ones, or something else?

Is the coil good? Otherwise no new ideas here either.

[e13h]

Sorry to beat a dead horse but no spark as in zero spark, ever, plugs don't give a spark to the block right? Just confused by why you changed the plugs for a no-spark, want to make sure I am on the same page.

When you say you "checked cam sensor and crank sensor" does that mean swapped in known good ones, or something else?

Is the coil good? Otherwise no new ideas here either.

The car had a massive hole in the oil pan when I picked it up. That has since been fixed. I replaced the spark plugs just given the old ones were OEM volvo plugs and none of the service records seemed to suggest that they had ever been replaced. I checked the crank sensor with the multimeter to make sure it was within the specs, but the cam sensor I swapped onto my wagon and the wagon cranked no problem, put the good one from the wagon on the R and it still wouldn't crank.

[erikv11]

OK cool spark plugs makes sense, cam sensor sounds good, crank sensor probably good, I get it there thanks. But is there spark, did you check for visible spark?

You said earlier it cranks fine with good compression so I'm assuming the earlier statement is true. So I assume you mean it cranks but does not start up? There could be spark without starting/firing, you have to check for visible spark or not. And of course it will never fire without fuel.

[e13h]

OK cool spark plugs makes sense, cam sensor sounds good, crank sensor probably good, I get it there thanks. But is there spark, did you check for visible spark?

You said earlier it cranks fine with good compression so I'm assuming the earlier statement is true. So I assume you mean it cranks but does not start up? There could be spark without starting/firing, you have to check for visible spark or not. And of course it will never fire without fuel.

Using a cheap inline spark tester I am not seeing anything. Recognizing that may not be the most effective way to check it, spraying some starter fluid in the intake there's not even a sputter. Haven't pulled the plugs and checked for spark visibly, currently fairly confident there is no spark across all five cylinders. Given it doesn't hurt to pull and check I will do that tomorrow.

[e13h]

While I had the multimeter out, I checked voltage to the fuel pump and it is getting battery voltage when it is supposed to prime so I can safely say the fuel pump is dead. What I can't figure out is when the key is in the accessory position the harness connection to the ignition coil is also showing correct voltage, but the coil is not providing spark. I swapped the coil from this car onto the wagon and it started the wagon up perfectly fine. I took the known good coil that was originally on the wagon and put it on this car, yet still no spark. What is the third pin in that connection? Obviously there is power and ground, but what does that third pin control in regards to the coil?

[misha]

Main fuel injection relay on fan shroud...the grey one....check it's connections too.

[Chuck W]

Certainly, something to look at. That relay connection dry rotted on my wagon as well but I never had a no-start problem because of it.

Look at that relay. It's the MAIN relay for the engine management. It will cause no fuel or spark.

[e13h]

Main fuel injection relay on fan shroud...the grey one....check it's connections too.

The idle air control valve is humming, which I thought was the sign that the relay was working in some capacity. Granted the IAC hums any time the battery is hooked up and not only when the key is in any specific position.