hey guys So i have a 5.7 TPi and am having issues getting it to Run It has been fitted with an aftermarket ECU and also an After market Fuel pump. Have been wondering if issue with getting it to run is fuel pressure. So i have fitted a gauge and am getting a reading of 41 psi with pump running but engine off, and about 32-35 when running, Is this enough for this engine? or should i look at installing an after market fuel pressure regulator. At the moent injectors are running at about 80% to just get it to idle, and it wont rev out past 2300rpm thanks in advance for any help! Allan

If I recall correctly. With the car running, and the vacuum line off the regulator, you should have around 45PSI at the rails.

no worries
Will check that and see what i come up with
Thanks

I too have the same readings, on a 90 tpi 305 41 and 32-34 running, tpis recomends 47 psi so we're way off the mark since 47 psi is with engine running that's 13-15 lbs difference way too much, but i'm not sure you should disconnect your vacuum to the reg, that's only when adjusting an adjustable reg like one from tpis. my car runs, but is lacking power and it's a bit rough. But what year is you car and is it MAF of SDS this makes a diff. but I do belive your pressure is low either way. low pressure comes back to a faulty fuel pump, too high a pressure is the reg.

The factory fuel pressure with the engine running and the vacuum line removed & plugged from the fuel pressure regulator is 43psi. Forget what TPIS might say on the matter. Start with the factory fuel pressure and then tailor to your specific mods. 32psi is too low, allowing the engine to run lean, then the ECM is going to try to richen things up alot. You might run out of correction room allowed in the ECM.

I have a ton of questions for you:
What aftermarket ECU are you talking about?
What size injectors are you running?
What is the ECU programmed with for injector size?
Injector duty cycle might be 80% at WOT,not at idle. You got big issues here.

ok, so do remove the vacuum line, I didn't do that. I'll try that, but I'm sure the pump is going out, it's getting louder and louder with a high pitch howl, and I can hear it struggling big time so it's time for a new one. my car is completly stock every thing redone back to stock, I'm looking for driveability. SEEDE AL has the mods.

I was addressing Seedy Al on all of my comments and questions. He is the thread starter.

Mine did the high pitch sound and retired, when I removed the fuel pump the filter/screen crumbled, rust was in the pump, the return line was stopped up with rust, and I had to take apart the fuel sending unit and clean up the contacts.

hey guys thanks for all the advice, So to make things easier, Lets just say the engine is no longer in a third gen body, and is infact in a toyota land cruiser.
the after market ECU is a Link G4, this is a map based ECU. The engine it self has no aftermark mods, we just found it would be easier to do aftermarket ecu so we didnt have to deal with factory inmobisler and all that stuff, and the injectors are factory. However the engine was made to try and run in the doner vehicle, and it was doing a similer thing, would only run very very short periods. We are also running an aftermarked Walbro fuel pump, which i can only assume would be upto the task for to supplying decent fuel pressure, however, there hae been issues in the past on other cars where this hasnt been the case. As for the duty cycle, i just took that off what my the guy who is tuning it said, he may have meant something else, but i am not sure. I since havnt been able to get it to idle again to check fuel pressure, so he is heading around again tomorrow to put play with the tune some more. And yes Doc, the Ecu is fully tuneable.