Wild1

The car was running with great. Hit 90 MPH on a cruise to see my dad. I filled up gas and it ran for about 10 miles. I stopped for a bite to eat at that time. When I started the car, it was a long crank. The engine would run for 15-25 seconds smooth... I could rev the engine to 4000 or 4500 smooth or just let it idle. Then, it would run rough then die.

I checked the voltage and I've got 12.4 which is good enough. I also just hooked up a jumper just to be sure and it is fine on voltage.

I'm wondering if the tank is overfilled? Would that affect this condition?

It just rained in So Cal over the past few days... I wonder if the station has a leak in the Premium Tank and some water got into the Station tanks. I put some Gumout Fuel Treatment to get rid of some of the "potential" water which I cannot test for.

So, it runs if I let it sit for a while... for about 20 seconds smooth, then 10 seconds rough, then stalls out.

Is it fuel? It can't be spark since it runs.

Injuneer

Overfilling the fuel tank would not cause that condition. Possibly its a batch of bad fuel, maybe dirty enough to have badly plugged the fuel filter. Possibly you've lost the fuel pump. Checking the fuel pressure would be a good place to start.

Wild1

Injuneer - I'll check the fuel pressure today. I was checking out Shbox's website and I'll check for 41 - 48 psi regulated.

What are the odds that the pick up sock is bad too? Do those ever get clogged? Should I replace both the filter and the pick up sock?

About 4 months ago I installed the Racetronix kit and it ran great. I hope the pump didn't go out. Also, the Racetronix wiring for the fuel pump was installed too.

The only reason I was concerned with overfilling was that maybe the canister was saturated which someone told me would affect idle. However, I'm not confident in that theory.

Injuneer

With the engine idling, and the fuel pressure regualtor vacuum line disconnected, you want 41-47psi (43.5psi preferred). When you reattach the vacuum line, the rail pressure will drop proportional to intake manifold vacuum, about a 6-8psi drop with a stock cam.

I would let it prime, watching the pressure, then watch the pressure as the engine starts and whether it drops just before the engine starts to run rough and stalls.

Wild1

I purchased a fuel pressure tester and it is connected to the rail.

The priming psi was 39-40.
Idle psi was 43.
Snap Throttle was 49 psi.
Unregulated psi was steady 46.

No fuel smell in the vacuum line to the regulator.

The fuel filter was replaced about 6 months ago. I can get another one but pressure seems to be fine.

The vehicle is dead cold since it has been sitting since yesterday. Open loop is typically on for about 2-3 minutes but I can't get it into closed loop yet since it stalls out in about 25 - 30 seconds.

Wild1

I just changed the fuel filter for the heck of it... still runs for about 20 seconds smooth and fine, then gets choppy, the stalls.

Fuel filter did not make a difference. Could the sock in the fuel pick up be clogged?

How can I tell if it is bad gas?

Injuneer

If some component of the fuel system was causing the engine to stall, it would show a significant pressure drop as it started to run rough and finally stalled. Did you check for that condition?

Wild1

I just ran another fuel pressure test with the new fuel filter (not sock).

Priming Pulse was 46 psi for 2 seconds... then when off went to 39 psi.
Cranking went to 47 psi, then 39 for 1/2 second then back up to 41.
Idle smooth at 41 psi.

When the engine starts to run rough, psi goes up to 44 - 46 psi. I assume since the vacuum is lower due to the rough engine concern that the regulated pressure goes high.

Then the pressure returns back to 41 psi and idles smooth.

One last rough idle sequence where the fuel pressure rises to 44 - 46 psi.

Then stalls and holds at 39 psi.

Wild1

I noticed that I didn't really answer your question.

At the moment the engine began to idle rough, the psi when higher to 44 - 46 psi.

When the engine smoothed out for a few seconds it was at 41 psi.

Wild1

I think I got it.

I went back outside and began doing some voltage drops on the positive and ground side. I found that the positive junction was dropping voltage. I cleaned up the junction connections and it runs.

I believe that the resistance was at the threshold where it was moderate enough to have enough current let the car start start, but as the resistance created more heat, it created more resistance. Ultimately, the resistance would shutdown power to the computer.

My fuel pressure remained high since it has the Racetronix harness that goes directly to the alternator which is directly fed from the battery. So, fuel pressure was normal.

It ran and I drove it around the block. I'll try a long distance run in a bit and see if it was entirely successful.