No/low fuel pressure
Posted: Wed Aug 13, 2014 5:45 pm
My 3.4 DOHC gradually lost power at my last track day and then I ran out of gas and/or the fuel pump died. As it was gradually losing the power the intake started sounding weird -- it was making a lot more noise. I'm not sure how much gas was left in the tank, but I added 5 gallons and it still wouldn't start. The paddock was pretty noisy so it was hard to tell for sure, but I don't think the pump was running. I assumed the fuel pump died and I burned some intake valves or something.
After I towed the car home, I pulled the fuel tank, replaced the fuel pump and filter, and put 3 gallons of gas in the tank. It started and ran, but was only running on a few cylinders and had no power. I swapped in my freshly cleaned and tested injectors (from Fuel Injector Clinic) and then it wouldn't start at all. As it turns out, all the injectors that were cleaned by Fuel Injector Clinic are completely stuck shut. After swapping fuel injectors back to a not-so-great spare set and replacing the spark plugs, it sounded like it was running on 6 cylinders again but at any reasonable throttle level it just crapped out. It was operating at maybe 30% power. The intake noise sounded weird also. Back to the burnt valve idea... we ran a compression check and all cylinders measure 150 to 160 psi. No problem there.
Next idea: catalytic converter melted?
I drove it around the block to get a baseline and then was going to pull off the exhaust to see if it made a difference. While pulling back up the street the engine died and acted like it was out of gas. Since I only had put 3 gallons in the tank, I thought maybe it was out of gas. Put 3 gallons in it and still won't start. I can hear the fuel pump running. With the pump running and a fuel pressure gauge attached to the rail it only gets up to about 5 psi. I pulled the fuel pressure regulator vacuum line and no fuel is coming out of it with the pump running, so the regulator diaphragm is not punctured.
Any ideas?
I can't remember if I replaced the pulsator with the short piece of fuel line that came with the pump, or just put the pulsator back in.
After I towed the car home, I pulled the fuel tank, replaced the fuel pump and filter, and put 3 gallons of gas in the tank. It started and ran, but was only running on a few cylinders and had no power. I swapped in my freshly cleaned and tested injectors (from Fuel Injector Clinic) and then it wouldn't start at all. As it turns out, all the injectors that were cleaned by Fuel Injector Clinic are completely stuck shut. After swapping fuel injectors back to a not-so-great spare set and replacing the spark plugs, it sounded like it was running on 6 cylinders again but at any reasonable throttle level it just crapped out. It was operating at maybe 30% power. The intake noise sounded weird also. Back to the burnt valve idea... we ran a compression check and all cylinders measure 150 to 160 psi. No problem there.
Next idea: catalytic converter melted?
I drove it around the block to get a baseline and then was going to pull off the exhaust to see if it made a difference. While pulling back up the street the engine died and acted like it was out of gas. Since I only had put 3 gallons in the tank, I thought maybe it was out of gas. Put 3 gallons in it and still won't start. I can hear the fuel pump running. With the pump running and a fuel pressure gauge attached to the rail it only gets up to about 5 psi. I pulled the fuel pressure regulator vacuum line and no fuel is coming out of it with the pump running, so the regulator diaphragm is not punctured.
Any ideas?
I can't remember if I replaced the pulsator with the short piece of fuel line that came with the pump, or just put the pulsator back in.