Stumped: No Fuel Pressure?

[3aG1e_7a1oN]

90 Talon N/T

So far I have replaced the fuel pump with a OEM replacement from Partstrain.com, the ECU which had a shorted capacitor (got new one from U-Pull-It, it was a 94 so I put pin 6 into 14) the fuel filter, and spark plugs. (Standard NGK gapped at .028) When replacing the fuel pump, we stripped the bolt on the fuel line so as a temporary solution (that I read by searching on this board) I used hose with two clamps on each side. At first the car could run, but felt like it was towing a boat behind it. It would constantly shake and sputter and stall.

I came back from a four day vacation, and the car wouldn't start. It would pop the first half crank, then just keep cranking after that. A friend brought over his logger and the injector pulse width was being strange. At half crank it would be around 6ms (a bit far but still close to where it should be) and after it would jump to 40+. Seemed like the injectors were working at 100% duty cycle leaving the engine flooded.

Since the ECU controls the injectors, I had a friend bring over a known working ECU and tried it out. It fired up eventually so to test our hypothesis, we put mine back in. It fired up with my ECU in (no visible damage on my ECU). The day after next, it would not fire up again. Being tired of playing games and solving this never ending mystery, I took it to a local shop down the street. They said there was no fuel pressure in the car at all, and the brand new filter I had installed was already clogged.

I assume the filter was clogged because the gas tank must be dirty as hell, but then what would explain the no fuel pressure. Could it by chance be the hosing I used as a temp solution for fuel line? And what would cause the strange pulse width?

I'm pretty sure the pump works because if I take off a fuel hose anywhere and crank it pukes fuel.

I just need some ideas, I'm completely stumped.

 

[3aG1e_7a1oN]

Could it be the fuel pressure regulator?

 

[3aG1e_7a1oN]

Or a bad MPI relay?

 

[cbr600teardrop]

whats your fuel pressure?

 

[DSM90AWD]

Are you sure your replacement ECU is for a N/T car?
ECU P/Ns

Also should make sure the pump was installed correctly in the fuel hoodie making sure the new o-ring did not twist up causing a poor seal (e.g. fuel pressure would piss out that connection back into the tank)

 

[3aG1e_7a1oN]

Are you sure your replacement ECU is for a N/T car?
ECU P/Ns

Also should make sure the pump was installed correctly in the fuel hoodie making sure the new o-ring did not twist up causing a poor seal (e.g. fuel pressure would piss out that connection back into the tank)

My ECU is from a n/t.

The pump was installed correctly and it works when cranking, the fuel pressure just jumps from around 40psi down to 5 and all around while cranking.

 

[cbr600teardrop]

When you turn your key on does the fuel pump turn on or do you have to crank it. If it turns on with out cranking does the pressure it 40 and stay or does it leek off fast.

 

[3aG1e_7a1oN]

When you turn your key on does the fuel pump turn on or do you have to crank it. If it turns on with out cranking does the pressure it 40 and stay or does it leek off fast.

Yeah sorry, It primes when the key is on, and when it is on the pressure is around 40. Then it leaks off.

 

[cbr600teardrop]

If it does leak off fast the you have a fuel leak. Most likely in the fuel injectors. check for a leaky fuel injector or one that is stuck open . or maybe even around the fuel pump.