help new to c4
#1
help new to c4
Hello everyone, I just purchaced a 94 automatic. It will only kick over for a split second after repedative cranking. Fuel psi gets to 30 but then just drops off to nothing.
#2
Team Owner
Sounds like a fuel pressure problem. Without more tests, we don't know if it is losing pressure at the regulator, the injectors or the "drain back valve" or all of them.
Crimp off the return line and turn the key to run position and see if it pressurizes up and how long it can keep it at that pressure.
Crimp off the return line and turn the key to run position and see if it pressurizes up and how long it can keep it at that pressure.
#5
Team Owner
#7
Team Owner
#8
Well sounds like fuel pressure issue. Start simple and work through it. 1) fuel filter, is it clogged? 2) regulator, is there gas in the vacuum line? 3) fuel pump, do you know when or if it was ever replaced? Are you getting good voltage to the pump? 4) injectors, any leaking down? are they reading spec resistance?
#9
Melting Slicks
If you crimp the return line and the engine runs better, that means to me that the pump is ok but the regulator / diaphragm is faulty. Find the vacuum hose on the diaphragm and if you pull this vacuum line and get fuel coming out, that means the diaphragm is bad. But please don't do this with a hot engine or with the ignition on (pump running) and be sure to have plenty of rags around.
Last edited by DGXR; 04-15-2019 at 01:00 PM.
#10
Team Owner
If you crimp the return line and the engine runs better, that means to me that the pump is ok but the regulator / diaphragm is faulty.
Find the vacuum hose on the diaphragm and if you pull this vacuum line and get fuel coming out, that means the diaphragm is bad. But please don't do this with a hot engine or with the ignition on (pump running) and be sure to have plenty of rags around.
Find the vacuum hose on the diaphragm and if you pull this vacuum line and get fuel coming out, that means the diaphragm is bad. But please don't do this with a hot engine or with the ignition on (pump running) and be sure to have plenty of rags around.
I wouldn't do that myself. Would not mind watching someone pull that hose FROM A DISTANCE ON THEIR CAR. Possible Barbecue moment.
#11
Thank you everyone
As soon as I get home from picking up my daughter I will check the pressure with the hose crimped. I know that the pressure goes up to about 35 after I turn the key on and then It drops quickly, this is with the hose not cramped. If anybody’s willing to talk me through it please call me anytime after four at 561-866-8934
#12
ok so I installed a fuel psi regulator, no change. the pressure is no effected by crimping the return line.It goes up to 35, with the key turned onand the and stays steady while cranking
#13
Team Owner
2. Turn key to RUN
3. See what pressure it gets
4. Turn key to off
5. Periodically check fuel pressure.
Nothing was said about cranking so not sure why you keep trying to crank and run.
What I am trying to see is what the pump does. With the return line crimpped it should go to at least 43 psi. It should hold pressure for a while. By cranking you change the test parameters.
#14
Ok so I took the pump out and some bozo used a peice oh hose tat was too short comming from the pressure line of the pump, so gas was just circulatiing in the tank. I hooked it up right and after a few cranks it started I ran it around the block and it stalled on me comming around the bend. Tomorrow i am replacing the pump with a fresh one....stay tuned. and thaks for all the support.
#17
Team Owner
Ok so I took the pump out and some bozo used a peice oh hose tat was too short comming from the pressure line of the pump, so gas was just circulatiing in the tank. I hooked it up right and after a few cranks it started I ran it around the block and it stalled on me comming around the bend. Tomorrow i am replacing the pump with a fresh one....stay tuned. and thaks for all the support.
My only concern is that it still stalls when you have connected it correctly. The hose is the replacement for the pulsator which is known to leak.
#18
Ok I replaced the fuel pump and its runninig BUT it dies after a few minutes a little hard to start again. runs then dies. I did not replace the fuel filter.
Last edited by Tony Patz; 04-16-2019 at 11:25 AM.
#19
Melting Slicks
#20