Ok, i have a four winds class c motor home on a 1991 e-350 cutaway chassis with the 7.5 liter efi engine with 75000 miles. I bought the rv from my landlord, he said it ran fine until he thought the fuel pump in the tank went out. It was parked in his yard where he decided to have a carport built, he needed to move it so the builders would have room to work, he started it ran fine and backed it up about 40 feet from its original location, and it never started again, it turns over but does not crank unless i use starting fluid, ok thats the back story, this is what i have done to it:
It only has one tank, i replaced the in tank pump
i replaced the pump on the frame
i replaced the fuel tank
i replaced the fuel pressure regulator
i had the computer rebuilt
i replaced the ignition control module
i replaced fuel pump relay and fuel injection relay.
i have tested the injectors, with key on red wire shows constant power as it should
i have tested for injector pulse while turning the engine over and the injectors have pulse
both fuel pumps operate as they should
the engine is also getting spark as it should
with all this done it still only turns over no crank unless i use starting fluid then dies when starting fluid is consumed
i have also checked the inertia switch it operates as it should
all fuses in fuse panel are good
oh and the cel does come on when key is on
PLEASE someone help me before i burn it to the ground!!!!!!

 

Sounds like no fuel pressure.
Put a fuel pressure gauge on it to test.
But it sounds like one or two of the fuel pumps are wired wrong and the fuel pump is running backwards.
When a fuel pump runs backwards you will have no fuel to the engine.

By the and engine that will not crank means that the starer will not turn the engine.
You are saying it will not start.
There is no such thing as a "fuel injection relay" in a gas truck.

 

yes, it will not start on its own it turns over but wont start, there is fuel getting to the engine, when i push the pressure release valve on the fuel rail it shoots gas clear across the engine bay, and about the relays i have two side by side and was told one is for fuel pump and the other is for the injection system. But no i haven't ran a pressure test, when i installed the new pressure regulator i figured that would solve any pressure related problems.

 

Don't assume; test. The big auto parts stores have free fuel pressure tester in their loan-a-tool program.

 

[QUOTE=lonewolf75124;20583. , and about the relays i have two side by side and was told one is for fuel pump and the other is for the injection system.

Yes one is for the fuel pumps and the other is for the PCM /Computer.

 

Ok, did pressure test, the pressure with just the key on was less then 10psi when turning the engine over the pressure was about 25psi. After i changed the pump in the tank the fuel gauge started reading backwards, could that mean that the pump may be wired wrong as well and fighting against the pump on the frame causing these low pressures?

 

Oof. Sounds like you got a mess on your hands. Did you buy fuel pump or the whole fuel distribution module with the float and hanger? Where did you buy it from? Did it have the same connector or did you have to splice in your own connector?

 

I bought the complete module, purchased from rockauto, and yes it had the same connector as original pump.

 

If your G100 ground is bad, it'll backfeed throu your fuel gauge and make it work backwards. I dont know where the G100 ground is on a Econoline but on a truck, its behind the drivers side headlight.

 

Hello, I couldn't find a specific answer to my question about my 1990 Ford e350 460 7.5L. During the Key On position is it normal for the check engine light to be lit? When the engine is running the engine light turns off.

More information is during the key on position (engine not running) there is a buzzing noise (which is normal) and my brake light is lit if the brake is engaged along with the engine light being lit until I start the car. Is this normal?

I live in California and need to pass smog and I am worried this will be an issue when testing.

thanks for your time and help.

Regards,
Wayne

 

Your dash lights are working normally so you are GTG. If the check engine light was not on at start up it is an automatic fail. It comes on and goes off GOOD!

They will dyno test your vehicle as it is an older model. Never had a problem down in Sandy EGGO LOL

B51

 

Please start your own thread. The thread you've jumped on is 13 years old. Go to the 1987-1996 F-150 and larger forum and click "Start new thread". It helps keep everything clean.