No fuel pressure

[vrinner]

So search around a bit and have the following.

Car will crank and try and start and then die.
Key-on fuel pressure gauge jumps a bit but stays at zero.
If I jump the fuel pump to stay on via the ECC connector it will hold about 20psi (low). I can start the car, it will run for about 10 seconds then die.

So im thinking obviously a fuel issue.

I put in a new filter (easy) and still does the same thing.
I pulled the vacuum line from the FPR and it's dry.

Fuel pump maybe? Some other clog somewhere else? There isn't any fuel leaking anywhere either.

These are supposed to get 35ish PSI with key on engine off right?

[svono50]

Yep, should be between 35-39psi with the EEC connector jumper (i.e.- engine off). Could be a clogged sock on the fuel pump, could also be a split line between the pump and head plate...if the pump is OK.

After you shut the pump off, does the pressure immediately drop or does it hold the 20psi for a while?

[GAboySVO]

At a recent track day event, my brother's SVO did something similar. It took a while to troubleshoot the issue, but ti turned out that unplugging the inertia switch and plugging it back in solved the issue. Also check the connector between the body and the fuel pump.

[vrinner]

I'll check the inertia switch...but the fuel pump is running.
I do the key-on and the EEC jumper and it will get to about 20psi. I can start the car, stays at about 20psi. Car will run but then die...PSI never goes above 20psi. Even after it dies with key on, stays at 20PSI, then key off and it very quickly drops to zero.

I see no fuel anywhere and dont smell fuel anywhere else either.

[vrinner]

Disconnected inertia switch and fuel pump didn't run. Reconneded and same issue. 20psi with EEC jumper. NO EEC jumper and pressure never rises. Gauge just blips then goes back to zero.

Fuel pump?

[GAboySVO]

If you are only getting 20 psi, that points to a fuel pressure regulator problem of the hose on the in tank pump in compromised. What happens when you cycle the key on/off several times in a row before starting? Does the pressure ever go above 20 psi? If not, try a new FPR.

[vrinner]

cycle on and off it barely moves. I have a couple spare FPR's, I'll give them a shot.

[scenario]

I would swap out with one of your spare FPRs, especially bc it is easy and quick to try. Go from there. If not the FPR then I think you gonna need to drop the tank...

[gbeaird]

I usually found that if the pressure didn't build after a couple of key on attempts, and the vacuum hose on the FPR was dry, the issue usually lay in the fuel pump. But that was for other FI cars, not the SVO. Our SVO suffered total FP failure because the gas went bad/rusty. New pump, tank filter, and all's better.

[svono50]

Based on those results, I would put my money on the riser hose from the pump to housing being split.

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[EVO SVO]

Just for your night time reading, some literature directly from the horses mouth. May not help since you seem to have gone over the usual suspects. But for me, when I can't solve the problem, I go back to square one to see if I missed something. Sorry I don't have a direct answer to your issue, but as a side note, 1986 holds about 30PSI when off (analog fuel pressure gauge)
And ignore the writing and yellow highlighter. Its the 1st and 3rd owners making their notes in the shop manuals as they worked on this 1986 SVO. Great reading and insight for me.

Best of Luck
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[vrinner]

Sorry for the long time between updates...lots of things going on. But I swapped out two FPR's and no change. Still with key on it just does a bump on the pressure gauge then drops to zero. Jumper the pump key on and barely gets to 20. Time to look at the pump I guess. Dang it.

[scenario]

It is most likely at this point the fuel pump. I had similar symptoms on my both my 85.5 and 86 and both times it turned out to be the pump. In some cases when the pump is starting to go out the fuel psi will immediately bleed back out to the tank as soon as you turn the key off.

[vrinner]

Pulled the fuel tank and pump...I think it may just be the hose is shot. After pulling it off, you can see daylight through it.

Part of me says put on a new piece of hose and re-install and the other part says just replace the pump as while I'm here.

Is there a way to test the pump?

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[MIKESVO]

Vince, you can run lead to the pump and check it with a 12 V battery. If it were me, I'd replace the pump. The car has been sitting and the pump will go. I did this on a 86 this summer, replaced it all, tank, pump and sender, just to ensure I didn't have to do it again. Mike