1997 850 GLT will only start on second try.

[jsrnsis]

I figured I'd start a thread to document what I've tried and the final fix once I find it.

We have a 1997 850 GLT that we've had for a few months. The previous owner had been jumping the car with a battery pack every time due to a bad battery, which masked the issue on the test drive. The car will not start on the first turn of the key, it has some light sputters and almost sounds like it's going to catch, but it never does. The second turn of the key causes the car to spring into life, and from there it drives beautifully.

No CEL on this car, just the ABS and TRACS lights because we haven't changed the module yet. We already tried changing the fuel pump relay with a known good one

At first it seemed to be doing it all the time, even if the car was off for a minute. Now it is only doing it after an extended period of being off, it will start fine even two hours after running. But it isn't my car so this could have been the behavior since the beginning.

Fuel pressure gauge hooked up, first turn to pos 2 brings up to 15 psi, second turn to pos 2 around 25 psi, 3rd turn to pos 2 to 35 psi. Turning the key to pos 3 shows 40-45 psi while cranking but car doesn't start.
The second time turning to pos 3, 40-45 psi and the car starts, and pressure drops to 35 psi at idle.

Leaving the gauge hooked up while idling it stays at around 35 psi, and stays steady for at least a half hour after the car is off.

I have no tried changing the injectors, but it doesn't seem like they're leaking due to the pressure staying steady. There was a large buildup of crud we saw in the intake and on the valves, especially the valves on cylinder #5.

I have checked the ECT resistance which seemed to check out normally, fan comes on when it's supposed to (250°F), and reading the temperature from the different modules through the 850 OBD2 app all seems correct.

All the plugs look great, and we tried changing the coil out, and increasing the gap to 0.030.
Cap and Rotor are what came on the car, as well as the plug wires.

Idle air control valve has been cleaned out, and tried swapping with a known good unit. Don't believe it to be the issue as the car idles and drives fine once it is started.

Ignition switch is another issue I was seeing, but there are no problems with shifting out of park, or headlights not working. Only electrical issues are the heated mirrors and rear windshield don't seem to work, and neither do the heated seats.

[erikv11]

Your hunch was correct, this sounds like a failed fuel pump check valve.

Turn the key three or even better four times to position II, give it a 1 second delay in position II before you cycle it off and back one, then psi will be near 45 and the lines will be primed - it should start right up on the fifth time when you go all the way to position III.

Some solution options:
1 install in-line check valve (a bit of a hack, risky with again fuel lines)
2 get a new fuel pump housing (the check valve is in the housing, not the pump or line)
3 live with clicking the key four times before you start it up.

With our 98 V70 I am living with option 3 for now, until I get around to option 1.

[jsrnsis]

Your hunch was correct, this sounds like a failed fuel pump check valve.

Turn the key three or even better four times to position II, give it a 1 second delay in position II before you cycle it off and back one, then psi will be near 45 and the lines will be primed - it should start right up on the fifth time when you go all the way to position III.

Some solution options:
1 install in-line check valve (a bit of a hack, risky with again fuel lines)
2 get a new fuel pump housing (the check valve is in the housing, not the pump or line)
3 live with clicking the key four times before you start it up.

With our 98 V70 I am living with option 3 for now, until I get around to option 1.

The weird thing is that even after cycling the key 3 times, and looking at the fuel pressure gauge sitting at 45 psi, the first attempt to start on a cold engine still lead to the stuttering. And the pressure stays steady at 35 psi even after 30 minutes of the car being off. I need to play around with it more today when I wake back up.

[misha]

You didn't mentioned that fuel filter was replaced.

[abscate]

Once you have a problem with fuel pressure , starting gets hard as incorrect amounts of fuel
Are being metered. It’s a fine line between too lean to start and too rich for compression.

[JimBee]

What happens if on a cold start, you leave the key in position II for a minute or more without trying to start it?

[erikv11]

Letting the key sit doesn't affect fuel pressure - the pump only runs for a few seconds with each key turn.

Mine takes 4 or 5 key cycles, 3 is rarely sufficient, and it still sputters sometimes. I can actually hear may fuel pump and I can tell when the lines are primed because the pitch in the hum drops. Then it starts right up.

A junkyard fuel pump is a very easy pull, cheap and an easy install. Just pay close attention to the gasket at the top. Fuel pump check valve failure is uncommon enough that this is a case where parts swapping can be a good diagnosis tool.

[jsrnsis]

You didn't mentioned that fuel filter was replaced.

Will be trying that tomorrow and reporting back.

What happens if on a cold start, you leave the key in position II for a minute or more without trying to start it?

Letting the key sit doesn't affect fuel pressure - the pump only runs for a few seconds with each key turn.

Mine takes 4 or 5 key cycles, 3 is rarely sufficient, and it still sputters sometimes. I can actually hear may fuel pump and I can tell when the lines are primed because the pitch in the hum drops. Then it starts right up.

A junkyard fuel pump is a very easy pull, cheap and an easy install. Just pay close attention to the gasket at the top. Fuel pump check valve failure is uncommon enough that this is a case where parts swapping can be a good diagnosis tool.

It's a hard thing to test out since the car needs to be left for hours before it's a true cold start. I tried relieving the pressure from the fuel rail to see if it would refuse to start again after a start cycle had been done a few minutes ago. The pressure at the rail was abysmal compared to the jet that comes out of the fuel rail of our other P80s. One little shot and then a dribble. No idea how the gauge was reading at the perfect pressure the other day when there seems to be a lack of fuel or pressure at the rail when the schrader is depressed with a small screwdriver. But the gauge also showed no pressure dropoff.

[jsrnsis]

A little update, changed the fuel pump out to a Volvo unit I had from a junkyard car. Issue persists. A pro parts sweden fuel pump and assembly came out of the car, making me think someone had already tried this to solve the starting issue. I have no idea if the pump I put in was also bad somehow, but the problem remains exactly the same, and the pump sounds healthy.
So far in the fuel system we have changed the fuel filter (Bosch came out, if it was changed from the factory it was a long time ago), used fuel pump, done a gauge test to verify it wasn't losing pressure.
Checked the spark plugs and all looked good, we increased the gap slightly. Tried a different (used) junkyard coil.
Car has a new (used) starter.

We still can't figure out what would cause an issue that clears itself the second time starting. Even letting it sit for 2 hours, it will start up without an issue. Leaving it overnight leads to the issue. It must be getting something the first try starting, as it will sputter and almost catch.

Trying to figure out what could possibly cause an issue when left alone for ~8 hours but not be an issue after ~2 hours.

[scot850]

Have you checked all the grounds are good?

Neil.