new to the forum/new to the FJ60 - question about questionable repair by PO

[turnpikegates]

Hello to all,

I just purchased my first FJ60 after years of lust and infatuation with these wonderful machines. I have some history working on vintage volvos over the years but I'm no ace mechanic, just a normal guy trying hard to keep his cars on the road.

Prior to purchase, the PO walked me through a fuel pump/Fuel Cut Solenoid mod that he performed and mentioned that it occasionally fails, cutting all fuel the carb. He also mentioned that I should just "jiggle" the wires a bit to get it going again. This is obviously not going to work.

The previous owner installed a generic electric fuel pump (the old mechanical pump is still bolted into the block). In doing so, he also messed with the wiring to the Fuel Cut Solenoid. The FCS wiring harness has been disconnected. There is a positive wire from the the fuel pump lead, which appears to originate from the ignition. For a ground he ran a wire straight from the Negative terminal on the battery to the FCS wiring harness using the type of alligator clips a dentist might use on a bib. The female end of the wiring harness is dangling unused below the carb.

The whole setup seems questionable to me and the vehicle has already stranded me three times since I bought it last week. I've parked it in the meantime but I'm looking to fix it as soon as possible. The fuel cuts out when the car is idling for more than 5-10 minutes. It's not a problem at stoplights but is a problem when sitting in traffic. The motor dies, starter will crank but motor will not fire up. If I let it sit for 10 minutes or so, it comes back to life.

Does anyone know why the PO would have disconnected the FCS wiring harness and introduced this very questionable wiring scheme?

I want to test the female end of the FCS wiring harness with my trusty multi-meter. Does anyone know what values I should expect to find or what resource I could use to help find this information on my own?

My goal is to retain the electric fuel pump (if it ain't broke...) but return the FCS wiring to its original state. If there are underlying symptoms I should be aware of, I'd like to chase those down as well.

Thanks in advance to anyone who can help! If this problem has been covered elsewhere, let me know where to go. I searched for fuel cut solenoid and browsed all the threads but didn't see anything related to my wiring problem.

Brian

 

[2mbb]

My recommendations:

Get a copy of the factory service manuals: IH8MUD Forums - View Single Post - FSM Prices??? You can also download the body and chassis manual from here: Downloads - Page: 1

Purchase a replacement mechanical fuel pump and get rid of the electric pump. Don't forget to install the spacer: IH8MUD Forums - View Single Post - Fual Pump Issue???

Use the search function to learn more about the fuel cut solenoid. This is a fuel switch that is controlled by the emissions computer to cut fuel to the carburetor slow circuit during decelleration. I don't know why the PO would wire the fuel pump to this circuilt. Usually an electric fuel pump is switched at the ignition switch but left to run when ever the engine is running. Some folks "hot wire" the fuel cut solenoid (run a wire from the ignition switch, bypassing the computer control. You might try that, if only temporarily to see if your problem goes away.

Do a search for the

 

[turnpikegates]

Thanks for the image and the tips.

I'm going to dismantle the PO's wiring this afternoon and troubleshoot from there.

The solenoid "clicks" when I disconnect/reconnect the hack-job wiring. I'll look for the same result from the original harness and also try it with a Pos wire from the ignition and a ground from the chassis.

will report back with any new info...

 

[Heartworm]

Get away from the electric fuel pump. There are very few threads on fuel pump issues which is good testimony of their reliability. Like the man said, be sure to use the spacer type gasket. One thought on the electric pump...What if you have a wreck and the fuel line breaks, will the electic just keep pumping gas into the engine compartment? At least the mechanical one won't.

 

[FJ40Jim]

Prior to purchase, the PO walked me through a fuel pump/Fuel Cut Solenoid mod that he performed and mentioned that it occasionally fails, cutting all fuel the carb. He also mentioned that I should just "jiggle" the wires a bit to get it going again. This is obviously not going to work.

The previous owner installed a generic electric fuel pump (the old mechanical pump is still bolted into the block). In doing so, he also messed with the wiring to the Fuel Cut Solenoid. The FCS wiring harness has been disconnected. There is a positive wire from the the fuel pump lead, which appears to originate from the ignition. For a ground he ran a wire straight from the Negative terminal on the battery to the FCS wiring harness using the type of alligator clips a dentist might use on a bib. The female end of the wiring harness is dangling unused below the carb.

The whole setup seems questionable to me and the vehicle has already stranded me three times since I bought it last week. I've parked it in the meantime but I'm looking to fix it as soon as possible. The fuel cuts out when the car is idling for more than 5-10 minutes. It's not a problem at stoplights but is a problem when sitting in traffic. The motor dies, starter will crank but motor will not fire up. If I let it sit for 10 minutes or so, it comes back to life.

Does anyone know why the PO would have disconnected the FCS wiring harness and introduced this very questionable wiring scheme?

OOH, I know the answer: Ignorance.

What did I win?

I want to test the female end of the FCS wiring harness with my trusty multi-meter. Does anyone know what values I should expect to find or what resource I could use to help find this information on my own?

The FCS itself should show continuity w/ a few ohms of resistance. If it is shorted to ground, or is open circuit, then replace.

The vehicle side should show open circuit w/ key off.
KOEO, it should have +12V on one wire, ground to the other.

 

[turnpikegates]

Ignorance was my first guess but it's hard to fathom considering the gentleman I bought it from works in a shop that services vintage euro race cars. I'm guessing that $70 bucks for a mechanical pump was too much dough when he could pull a random electrical pump off the shelf for free.

I'm not at all interested in a horrible fire in the event of an accident. I've seen this happen to others in the past with grave results. I'll be moving back to the mechanical as soon as I can get the parts.

I have a few more observations since my original post that I should probably throw into the mix:

- there is no click from the FCS when I connect up the original wiring.

- there is little fuel in the filter between the tank and the electrical pump (i expected a full filter if the pump was doing it's thing and the car wasn't firing up)

- there is a plugged-off fuel line about 3" from the electrical fuel pump. What's up with this? I don't see any other plumbing for a return line. My initial inspection of the mechanical fuel pump didn't turn up a barbed end for this fuel line. Is there accommodations for a fuel return line that has been ignored by the PO's mods?

- the electrical fuel pump quivers and shakes a bit during the no-start episodes. I didn't notice this until it happened again this morning.

I drove the truck about 2 miles this morning to grab a bite to eat. Started up and ran fine. Stopped for coffee on the way home, got back in and drove a block before the engine quit. It's parked safe for now and I'll head back out in a bit to make some more observations.

Thanks,

Brian

 

[FJ40Jim]

Where is the electric pump located on the truck?

If the ICS won't click when plugged into the stock harness, test the harness for 12V and ground.
If there is no 12V, then trace down problem in ignition switch/engine fuse/wiring.
If there is no ground, then just make a connection between the ground wire and a good ground. This will bypass the computer's decel fuel cut function, but that's OK for now. The emissions computer is not as reliable as the rest of the Cruiser, so bypasing it is not an entirely bad thing.

 

[turnpikegates]

The electric pump is located between the block and the passenger-side fender well. It is attached to a metal bracket that, at first glance, appears to be an original part of the car. Not sure what went there before the fuel pump took up residence.

It's probably gonna be next weekend before I tear into all of this. I'll need to get a manual and a fuel pump and then set to work making things right under the hood.

Still not clear on the plugged-off fuel line.

 

[ntsqd]

A correct mechanical pump will have a barb for that return hose.
I'm guessing the correct fuel filter used to live in that bracket, but I've been wrong before.

All that is needed to prevent electrical fuel pump run-on is a GM Vega fuel pump switch. Little to no oil pressure (except in crank mode) = no fuel pump. Can also use a late model's Inertia Switch to kill an electrical fuel pump in the case of impact.

 

[Elbert]

post up some pictures if you can....would probally help to see what you are referring to as far as mounts and hoses...