3f-e Intermittent throttle?/fuel? loss? (1 Viewer)

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Apr 5, 2013
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Behind The Beard
Joined
Mar 8, 2015
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Location
Elverta, CA 95626
I went through similar issues with my 91.

Intermittently, it would just fall on it's face when coming to a stop, then trying to take off again. I would limp it to the shoulder, but it would rev just fine in Neutral. Pop it back in gear & it wouldn't rev over 1200 RPM.

Then, suddenly, it'd run perfectly fine again. Sometimes just until another stop sign, other time for hours.

I went through a series of troubleshooting steps & throwing parts at it; including an ECU, AFM, Coil, Igniter, Coolant Temp Sensor, EFI Relay, Fuel Pump & Sock, Fuel Filter, Throttle Position Sensor, Intake Hoses, and... well, I'm sure I'm leaving out a few things.

Through all of this, I did find a couple of issues.

First, was a series of crappy reman brake boosters. One of which appeared to becoming unbonded (the diaphragm to case) when it sat in the sun & warmed up, thus creating a vacuum leak. A new Seikin booster from Curt at Cruiser Yard fixed it. For a while, anyway.

Then, out of the blue, it did it again. ONCE, then it was OK for a few days. Then, one morning on the way to work, at a stop sign, it died & wouldn't start again. After sitting for about 15-20 min, it started back up & I managed to get it home.

Further digging, uncovered a melted wiring harness; under the intake manifold, near the rear of the valve cover.

I managed to obtain a good used harness & this has now resolved the issues. No more hiccups or stumbling. Unfortunately, that didn't seem to improve my horrid fuel economy, as I had hoped it may. But, hey a guy can wish right. I guess 37's with stock gearing & trying to drive it like a hot rod are probably the underlying reason for sub 6mpg numbers.

But remember...

One does NOT drive a LandCruiser because it is financially practical. It's all about that "FEELING"

 
Joined
Apr 5, 2013
Messages
215
Location
Behind The Beard
I went through similar issues with my 91.

Intermittently, it would just fall on it's face when coming to a stop, then trying to take off again. I would limp it to the shoulder, but it would rev just fine in Neutral. Pop it back in gear & it wouldn't rev over 1200 RPM.

Then, suddenly, it'd run perfectly fine again. Sometimes just until another stop sign, other time for hours.

I went through a series of troubleshooting steps & throwing parts at it; including an ECU, AFM, Coil, Igniter, Coolant Temp Sensor, EFI Relay, Fuel Pump & Sock, Fuel Filter, Throttle Position Sensor, Intake Hoses, and... well, I'm sure I'm leaving out a few things.

Through all of this, I did find a couple of issues.

First, was a series of crappy reman brake boosters. One of which appeared to becoming unbonded (the diaphragm to case) when it sat in the sun & warmed up, thus creating a vacuum leak. A new Seikin booster from Curt at Cruiser Yard fixed it. For a while, anyway.

Then, out of the blue, it did it again. ONCE, then it was OK for a few days. Then, one morning on the way to work, at a stop sign, it died & wouldn't start again. After sitting for about 15-20 min, it started back up & I managed to get it home.

Further digging, uncovered a melted wiring harness; under the intake manifold, near the rear of the valve cover.

I managed to obtain a good used harness & this has now resolved the issues. No more hiccups or stumbling. Unfortunately, that didn't seem to improve my horrid fuel economy, as I had hoped it may. But, hey a guy can wish right. I guess 37's with stock gearing & trying to drive it like a hot rod are probably the underlying reason for sub 6mpg numbers.

But remember...

One does NOT drive a LandCruiser because it is financially practical. It's all about that "FEELING"

Thanks for the info. I'll keep those things in mind.
For now the plan is to daily drive it and try to diagnose it on the side of the road if it breaks down. I have an assortment of tools, an FSM and AAA. Hopefully that's enough.
 
Joined
Apr 5, 2013
Messages
215
Location
Behind The Beard
Quick update. I've been driving it daily and I finally got a code 28. I'm not sure if a faulty o2 sensor could cause the problem I've had or not but, it gives me somewhere to look.
 
Joined
Sep 11, 2019
Messages
15
Location
Seattle, WA
apparently, tis the season. My '91 stalled while on a slight incline and refused to start back up tonight.
I'll be watching this thread as I figure out what's wrong.
 
Joined
Apr 5, 2013
Messages
215
Location
Behind The Beard
I'd highly encourage you not to wait on me. I daily drove it December thru most of February without this particular problem reappearing. I'm thinking it's heat related, but it's not gonna be hot here for a couple of months and with gas prices going the way they are, I don't think I'm gonna drive it super often.

I did replace the o2 sensors but haven't noticed any glaring difference.
 

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