3FE 1992 80 Won't Start.. Complicated issue (2 Viewers)

[bencho]

Took my 1992 FJ80 (3FE) to the shop last week for a thermostat replacement. They swapped it out no problems, got my heat back, but then he called me and said the truck wouldn't start. Never had this issue before my mechanic worked on it. He put brake cleaner "down a vacuum" which gave it enough to get it to start up. I've heard that's an unsafe substitute for starting fluid... Anyways, I replaced the EFI relay, fusible link, and even the spark plugs. No CEL when I turn the key but sometimes I get the oil light and battery voltage indicator when I turn it on, sometimes I don't (as shown in video). In the Minnesota cold, it starts up eventually but after some rough cranking. Once I get the engine warmed up, it normally restarts without too much issue at all.

IMG_0346 2.mov

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Getting pretty frustrated with this. Any advice or help would be greatly appreciated

 

[LandLocked93]

The video sounds very fuel pump related. The sensitivity to heat seems to second that assumption.
Admittedly it's coincidental to the repair you had done.
Have you inspected your fuel tank and fuel pump assy? Pump sock too?

 

[jonheld]

No CEL when I turn the key but sometimes I get the oil light and battery voltage indicator when I turn it on, sometimes I don't (as shown in video).

Read through this document:

General Tech - 3FE EFI Diagnostics

3FE EFI Diagnostics updated for 2020

forum.ih8mud.com

 

[bencho]

The video sounds very fuel pump related. The sensitivity to heat seems to second that assumption.
Admittedly it's coincidental to the repair you had done.
Have you inspected your fuel tank and fuel pump assy? Pump sock too?

Ah thank you! I haven't inspected it yet, I wouldn't really know what I to look for.. just ordered a new "circuit opening relay" (as recommended in this video at 1:38). Not sure if it'll actually do anything ha.

 

[bencho]

Why would my A/T & Charge lamps sometimes light up and sometimes not?

 

[jonheld]

Why would my A/T & Charge lamps sometimes light up and sometimes not?

Did you read the document I posted?

 

[bencho]

Did you read the document I posted?

Ahh sorry yeah. I inspected the IGN and ignition switch. They're not blown but the IGN has corrosion on it. I'm assuming my fusible link AM2 is good since I just replaced the whole thing so hopefully replacing the IGN might give me lights back?

 

[bencho]

Gonna pick up an ohm meter today to check the fuses and whatnot

 

[bencho]

Would this indicate that my circuit opening relay is good and not the issue?

 

[bencho]

I'm rly sorry for spamming posts here but was also wondering what this exposed connector is for?

 

[bencho]

Last post until I start getting answers I promise!... Found some severed wires near the driver's side kick panel. One seems to be a black and white cablem, the other a ground cable, and then a group of 5 or 6 cables that look to have been all cut off... any help on identifying these cables and their roles would be great!

Fuel Pump Issues

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[BreezyF]

Sounds like opening circuit relay or the fuel pump.

 

[jonheld]

OK, lets start from the beginning.
As stated several times in the document, this engine WILL NOT RUN without the CEL illuminated with the key in the ON position before cranking the starter.
There are several diagnostic steps outlined in the document, along with several possible causes. Please follow the instructions and let's figure out what the problem is.
If you're going to jump to conclusions without performing any diagnostics, it's not going to work out.

 

[bencho]

Took it to the shop. They found that the Cold start ignition time switch (or whatever it's called) harness was severed and in rough shape. They weren't able to recreate my issue oddly enough but now she starts up just fine. Hopefully it stays that way!

 

[boobaa]

Took it to the shop. They found that the Cold start ignition time switch (or whatever it's called) harness was severed and in rough shape. They weren't able to recreate my issue oddly enough but now she starts up just fine. Hopefully it stays that way!

Buy the factory service& repair manual to help you out ......Im coming in late but the cold start injector and wiring would be part of the issue. With my 92, first thing I did was disconnect and lube all electrical connections, plugs, fuse & relay blades with dielectric grease to make them easier to disconnect/reconnect and fend off corrosion due to salt and moisture