Archie,
Since it is cranking and sometimes starting you know that the electrical is good (i.e. coil, ignitor, ECU, EFI Relay, and Fuses.) I’m not an expert on the airflow meter so I can’t get into that. You know it’s getting some fuel because it starts occasionally. You can get it to crank all the time so it’s not the starter. That leaves the mechanical fuel system.
Possible Problems:
Fuel Pump going bad and not delivering enough pressure
Fuel Pressure Regulator (I hate when people suggest this as one of the first solutions since the FPR is usually good, don’t throw money at this until checking everything else.)
I would try loosening the banjo connection as stated above. The one that is on the driver’s side, at the top of the manifold is where you should check. If the fuel doesn’t spray out hard then you have something restricting the fuel pressure. The easiest fix and something you should do anyways is replacing the fuel filter. That is good for your truck in the long run and not too expensive. It probably won’t solve the problem so if you’re on a tight budget pass on buying a new filter.
Go to your diagnostics circuit box (on the passenger side firewall) and connect Fp and +B circuit. This bypasses the electronics that control your fuel pump (i.e. ECU, circuit opening relay and EFI Relay) and allows the fuel pump to turn on without the car cranking. Loosen the banjo bolt referenced above and see if you get good pressure. If you do then you can rule out your fuel filter, fuel lines, and fuel pump. That leaves you with the FPR and injectors. I can’t offer anymore assistance as I don’t know much about the injectors, cold start injector, and airflow meter on your air box.)
Mark W,
I have never heard of the “circuit cutoff relay” on my 62. I had fuel pump problems about 6 months ago and during my troubleshooting I never came across that on the wiring diagram in the FSM. Can you fill me in a little more on where it is or what its purpose is? Just to make sure, we are talking about an FJ62.
