Hey guys! so just a bit of trouble shooting here, i have a Jeep TJ, i replaced the fuel pressure regulator and the fuel pump to try to fix the long cranking times, and its still doing it!, it starts fine if its only been sitting a short while.Its been a few months since iv changed them,so today i went into canadian tire and hired the fuel pressure test gauge, so the pressure spikes up to 50 psi when i turn the key on, then a second later it just drops right off to under 10 psi even before iv started cranking, iv checked all the injectors they are all working while engine is running,could one be leaking while engine is off?? it has to be the fuel pressure reg letting the pressure return???!!! any help is appreciated
What trips the reg vacuum or electric
I'm just about to pull the injectors on my ranger for the same issue. It's probably either a leaking injector or the one-way valve in the tank. If you turn it off and let it sit for a few minutes and then start it again, does it run rough at first? Does your engine oil smell of gas at all? These are signs of leaking injectors. If you pull them out you can try putting compressed air at a suitable pressure into the fuel rail end and stick the other end into a cup of water and look for bubbles to see if they are leaking.
When you replaced the pump was it the whole assembly or just the actual pump? On my truck the one-way valve is part of the pump assembly but it is possible to replace just the pump and therefore not solve the problem.
the regulator is just spring loaded check valve, i didn't replace the whole unit, just replaced the pump and fuel filter in the tank and then the regulator.
I'm thinking I'm going to have to drop the tank again, and pull the pump assembly out and attach the fuel line and see if there is fuel returning when the pump is on, the 50 psi of pressure drops off in seconds... getting tiered of all this cranking,
have to say though, jeep put some dam fine starters in these things!
Yes it just a check val and spring if its not holding it will dump the fuel back to return line i a sec so no holding pressure in the fuel rail i am not sure if jeep uses a check on the pump to stop fuel from dumping back when pump is off but there has to be one on the supply some were