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Spduffee
03-05-2020, 10:48 PM
15185

Hello All,
I'm new here, trying to change from a carburetor to EFI on my '86 Jeep Grand Wagoneer. I received a box of stuff with what I think is all I need...I think.
Does anyone know what this thing is? I can see inside there is a circuit board. No markings, no nothing to identify.
Any clues would be appreciated.

Thank you,

Shawn
1project2many
03-05-2020, 11:41 PM
That appears to be a diode module or a "hot fuel handling" module. What year truck are the parts from?
Spduffee
03-06-2020, 04:05 AM
That appears to be a diode module or a "hot fuel handling" module. What year truck are the parts from?

1project2many,
Love your handle; sums up my life, but better too many than not enough...Thank you for the response.
The box of parts came from an '87 5.7l motor, that's all I know. The thingy came with, but not attached to any other thingys.
I'll have to dig up a circuit diagram from a truck of that year/size to see where that belongs.
1project2many
03-06-2020, 05:16 AM
If it's '87 then it's probably "hot fuel handling" and likely from a one ton or three quarter ton truck.

Hot fuel handling was simply extended pump run time at key on (or off, can't quite remember anymore). The pump would continue run for an extended time, presumably to reduce vapor formation in the fuel lines from heat soak. Most projects don't use it.

This thread contains pictures of the module and has schematics.
http://67-72chevytrucks.com/vboard/showthread.php?t=429691
Spduffee
03-06-2020, 12:01 PM
If it's '87 then it's probably "hot fuel handling" and likely from a one ton or three quarter ton truck.

Hot fuel handling was simply extended pump run time at key on (or off, can't quite remember anymore). The pump would continue run for an extended time, presumably to reduce vapor formation in the fuel lines from heat soak. Most projects don't use it.

This thread contains pictures of the module and has schematics.
http://67-72chevytrucks.com/vboard/showthread.php?t=429691
Ok, that makes sense. I probably won't need it, but the GW's do - I think mistakingly- have a reputation for being prone to vapor lock. I tend to believe it's a combination of badly tuned carb aspects but....
Thanks again!