Timing mark unreadable.

[Dale Stevens]

D, place a piece of plywood or so under the tank; have someone crank the engine while you hammer the hell outa the tank. May jar that new pump to life; has worked many times, Dale

 

[Schurkey]

For ****'s sake! Instead of beating, banging, replacing relays...how about putting power to the fuel pump bypass connector, and seeing if the pump runs?

If the pump runs and you crank the engine and the engine starts after you put power to the bypass connector, the pump is good, the filter isn't plugged, and the hose connecting the pump to the fuel pump hanger tube probably isn't ruptured. You can start checking the wiring to the pump ahead of where the bypass wire connects, because it's not likely a mechanical fault, and it's not a wiring fault rearward of the bypass wire.

If you put power to the bypass connector, and the pump DOESN'T run, or runs but doesn't produce pressure/volume, you've likely got an in-tank problem, or faulty ground wire for the fuel pump. You might have a broken wire between the fuel pump and where the wire harness joins the bypass connector wire.

 

[DeCaff2007]

So.... I ended up accidentally destroying one of my brand new fuel lines, and it just happens to be the return line from the TBI, going down the firewall, etc, etc... Idiot me didn't use two wrenches to loosen the line, and I ended up twist-kinking the line @ the TBI adapter fitting. I had special ordered that entire fuel line set from a random online vendor.

The only way to find a replacement immediately at this point in time would be a junkyard, so that's where I spent my afternoon. I found enough of the fuel line to be able to craft a replacement. Also, as much as I don't like compression fittings, I believe they are still acceptable for fuel lines to pass inspection. It's brake lines that require unions and inverted flare nuts. Am I right?

Lastly, the parts stores used to close @ 9pm or later around here. Ever since the political virus, many stores have either started closing @ 7pm, or have shut down altogether. The reason I mention this is because I don't have either of the above (compression nor union fitting). Can't go buy any if all the stores are closed.

@Schurkey: By the bypass connector, are to referring to the green, 1-wire connector behind that plastic cover on the passenger side of the firewall? If not, could you clarify?

P.S.: It's time to go on Ebay and find a cheap camera. Pics make threads more readable.

 

[Nad_Yvalhosert]

Also, as much as I don't like compression fittings, I believe they are still acceptable for fuel lines to pass inspection. It's brake lines that require unions and inverted flare nuts. Am I right?

Spot on accurate.

 

[DeCaff2007]

So, where's this fuel pump bypass?

 

[DeCaff2007]

Ok I think I've got it. It seems there's a +12Vdc Fuel Pump Test Terminal on pin G of the OBDI connector. So by GROUNDING pin G, it should turn on the fuel pump.

 

[PlayingWithTBI]

So by GROUNDING pin G, it should turn on the fuel pump.

Nope, you APPLY 12VDC to pin "G"

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[DeCaff2007]

I'll give it a try tonight after work. Also, why not just apply 12Vdc to pin "E" on the relay? Same effect if the relay is bad.

 

[BeXtreme]

I'll give it a try tonight after work. Also, why not just apply 12Vdc to pin "E" on the relay? Same effect if the relay is bad.

Because you have to unplug things to do that. If you just apply 12 volts to "G", and the pump kicks on, then you know that either the relay is bad, there is a problem in the relay control circuit, or there is an issue in the power feed to the relay. If it doesn't kick on, then you go the other way and start checking the in-line fuse and power/ground connections around the pump.

In other words, you apply the voltage there because it will narrow down where to check next. Once you have jumped power to the test pin, you can basically check the whole circuit with a test light in just a few minutes without unplugging anything.

 

[DeCaff2007]

12V to the G pin = nothing.
12V to the E pin on the relay = nothing
12V on the fuel pump side of the inline fuse = nothing

Time to pull the effing bed.