Hearing fuel spray but no pressure on fuel rail

[Project91Jp]

So I'm trying to get my 91 parts truck/storage truck going. I replaced the fuel relay, filter, and pump. When I turn the ignition to ON, I can hear gas spray under the intake. No fuel pressure, though. Any thoughts?

 

[Josh P]

When was the last time it ran before parked? My friends 89 F250 had the gas gel up in the fuel lines. Took 2 weeks of running the pump several times for a few seconds each day.
I'd pull one side of the fuel filter and jump the fuel pump relay to verify fuel to that point.

 

[Project91Jp]

Good point. I know it's good at least to the filter. I already pulled off the filter and flushed all the fuel from there. Some of it was black.

I'm hoping it's that or the expensive fuel pressure regulator. I don't want to mess with the injectors yet lol.

Edit: it was last started probably around 2018. That was the last time it was tagged. I bought it from the previous owner's estate in 2022.

 

[Josh P]

Good chance the fuel is gummed up in the lines, if you have nothing at the rail. Acetone helps dissolve the dried up stuff.

 

[Project91Jp]

Could be. I took your idea and checked at the fuel pressure regulator. I disconnected the hose on top and stuck a bent soda bottle to catch the gas. It gushed out but looked normal. Thanks for helping me troubleshoot by the way.

 

[Josh P]

Could be. I took your idea and checked at the fuel pressure regulator. I disconnected the hose on top and stuck a bent soda bottle to catch the gas. It gushed out but looked normal. Thanks for helping me troubleshoot by the way.

Ok, so you got fuel to the rail. You sure this is a no pressure issue and not something else like no spark?

 

[Project91Jp]

I reinstalled my harbor freight compression tester. It still shows zero pressure while the pump is priming. I'm hoping it's not the injectors gone bad. I wanted to check with you guys before digging myself in a hole.

The spark is next on the troubleshooting list when my helper gets free time.

 

[Josh P]

I reinstalled my harbor freight compression tester. It still shows zero pressure while the pump is priming. I'm hoping it's not the injectors gone bad. I wanted to check with you guys before digging myself in a hole.

The spark is next on the troubleshooting list when my helper gets free time.

Try pushing the valve in on the rail, if gas shoots out I'd suspect an issue with the gauge cause that would be more than 0 psi worth of fuel coming out.

Edit: just caught what type of tester you are using.

 

[Project91Jp]

You are correct. When I primed it. It sprayed everywhere lol. Looks like I need to get a different one. Thanks a bunch man. I'll update when I pick one up.

 

[Project91Jp]

Alrighty then. I had a user error. After trying out O'Reilly's loaner test kit, I realized the Ford adapter wasn't tight enough.

Anyways, I have pressure now. It'll shoot up to about 39 psi then rapidly drop to 19 psi before gradually drop to 0 psi. Is that normal?

 

[Josh P]

39 psi is healthy and the pressure drop is normal cause the pump only runs a few seconds when the ignition is in the run position before the motor starts. There isn't a one way check valve to hold pressure at the rail when the pump stops running.

Does the check engine light illuminate when cranking the engine.

 

[Project91Jp]

I wanna say no based on memory. I'll have to recheck tomorrow. I was following the directions on this list:

How to: - Ford Explorer Engine No Start Procedure

This procedure diagnoses a No Start engine problem. The procedure is based on information from the Ford Service Manual and my personal experience. The numbered steps should be performed in the order listed. 1. Does "THEFT" blink rapidly with ignition key in Off, On or Start? Yes: Verify key...

www.explorerforum.com

It looks like I'm going back to step 9.

 

[Project91Jp]

I'm determined to get this to run lol.

It's very blurry but when I'm cranking, the only lights on are check oil and the e brake (e brake obviously pushed in).

My next move was to check the coil. According to a YouTube video (link below), the secondaries appear normal (picture above). The primaries appear not (no pic). The resistance reading was .1-.2 ohms. Below the recommended specs.



Primary: .3-.9 ohms
Secondary: 11k-17k ohms

Lucky for me, the previous owner had a spare working coil in the hatch. I just need to get a screwdriver.

 

[Josh P]

The check engine light is to confirm you have crankshaft position sensor signal. Verify the bulb is good. If the bulb is good and doesn't illuminate while cranking then you have an issue with the crank sensor.

 

[Project91Jp]

One step ahead of ya.

 

[Josh P]

Check fuses and confirm 12v to the coil?

 

[Project91Jp]

All fuses are good. I haven't done that second part yet. Thanks again for helping me along.

 

[Josh P]

Since you confirmed the check engine light works, does it turn off while cranking?

 

[Project91Jp]

That it does. I took that last picture first ironically. All the lights lit up in the ON position and only the low oil during cranking.

 

[Josh P]

Check your crankshaft sensor, usually the plug goes bad. Sometimes reseating the connector on the sensor temporarily will make contact again.