850R No Spark

[e13h]

Recently picked up an 850R but getting a no spark condition. Checked cam sensor, crank sensor, swapped rotor and cap, swapped ecu, changed plugs, did the whole nine yards. I'm looking for the next diagnostic step and maybe off the wall solutions to check.

[Clemens]

Does it crank?
Are you getting fuel?
I guess yes, just asking.
And I guess you have an US model, so no anti theft circuit that could screw things up?

[Nevada1906]

My 850 once decided it'd be hilarious to have it's main fuel system relay not work. It's the big grey one in the top radiator shroud. I replaced it with a new Volvo part (after I figured it out - to be safe) and the problem went away pretty much forever.

Here's my original solution post:

"Actually, I found the problem and my car runs now. I was right; it WAS something stupid.

ONE. EFFING. WIRE.

One of the large red wires that goes into the main fuel system relay became disconnected when I reinstalled the thing into the radiator shroud, preventing the computer from firing the ignition coil. See, the soft insulator had completely rotted out of the connector, leaving the wires hanging in open space, and one of them popped out when I tried to force the relay into its normal home in the rad bracket. I'm fabricating a bracket to hold it in place next to the upper intercooler hose, just to keep the wires in a straight line going into the bloody thing.

Oh well, at least I have new sensors and an ignition coil now.

Thanks to everyone who offered their help. I have my car back now, and there was much rejoicing."

This drove me nuts at the time as well. I also relocated the relay to "fix" the problem, which it did. This mod lasted for 70,000 miles, by the way.

IMG_0692.JPG (62.48 KiB) Viewed 425 times

[e13h]

Does it crank?
Are you getting fuel?
I guess yes, just asking.
And I guess you have an US model, so no anti theft circuit that could screw things up?

Yes it cranks, turns over freely with compression.
No, there is zero pressure at the rail but I have mainly just assumed that given the car has sat for three years prior to my ownership the fuel pump would be a no brainer. I did change the fuel pump relay with a known good part but cannot hear the pump prime at all. I haven't checked voltage to the pump though, been hopeful that my problem is not that significant
Yes, USDM spec 96 car.

[e13h]

My 850 once decided it'd be hilarious to have it's main fuel system relay not work. It's the big grey one in the top radiator shroud. I replaced it with a new Volvo part (after I figured it out - to be safe) and the problem went away pretty much forever.

Here's my original solution post:

"Actually, I found the problem and my car runs now. I was right; it WAS something stupid.

ONE. EFFING. WIRE.

One of the large red wires that goes into the main fuel system relay became disconnected when I reinstalled the thing into the radiator shroud, preventing the computer from firing the ignition coil. See, the soft insulator had completely rotted out of the connector, leaving the wires hanging in open space, and one of them popped out when I tried to force the relay into its normal home in the rad bracket. I'm fabricating a bracket to hold it in place next to the upper intercooler hose, just to keep the wires in a straight line going into the bloody thing.

Oh well, at least I have new sensors and an ignition coil now.

Thanks to everyone who offered their help. I have my car back now, and there was much rejoicing."

This drove me nuts at the time as well. I also relocated the relay to "fix" the problem, which it did. This mod lasted for 70,000 miles, by the way.


IMG_0692.JPG

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.

[erikv11]

Does it crank?
Are you getting fuel?
I guess yes, just asking.
And I guess you have an US model, so no anti theft circuit that could screw things up?

Yes it cranks, turns over freely with compression.
No, there is zero pressure at the rail but I have mainly just assumed that given the car has sat for three years prior to my ownership the fuel pump would be a no brainer. I did change the fuel pump relay with a known good part but cannot hear the pump prime at all. I haven't checked voltage to the pump though, been hopeful that my problem is not that significant
Yes, USDM spec 96 car.

Zero pressure at the rail makes it a fuel supply problem, not a spark problem (unless it ALSO lacks spark).

Fuel pump is top candidate now or the fuel pump circuit, I'd get out the voltmeter.

[scot850]

Did you swap the fuel pump relay? Do hear the pump whirr at all when you switch the key on in the ignition?

Neil.

[misha]

I didn't read in your posts that you actually replaced a fuel pump....just fuel pump relay.

[e13h]

Does it crank?
Are you getting fuel?
I guess yes, just asking.
And I guess you have an US model, so no anti theft circuit that could screw things up?

Yes it cranks, turns over freely with compression.
No, there is zero pressure at the rail but I have mainly just assumed that given the car has sat for three years prior to my ownership the fuel pump would be a no brainer. I did change the fuel pump relay with a known good part but cannot hear the pump prime at all. I haven't checked voltage to the pump though, been hopeful that my problem is not that significant
Yes, USDM spec 96 car.

Zero pressure at the rail makes it a fuel supply problem, not a spark problem (unless it ALSO lacks spark).

Fuel pump is top candidate now or the fuel pump circuit, I'd get out the voltmeter.

Correct, no fuel and no spark.

[e13h]

Did you swap the fuel pump relay? Do hear the pump whirr at all when you switch the key on in the ignition?

Neil.

Yes, swapped the relay itself but the pump is not priming. No sound in the accessory position.