87 Fj 60 Will not idle. Tried all of the common fixes. No solution :-/

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Jul 20, 2021
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Howdy guys,

Bought an 87 FJ 60 and inherited some problems. When we got it running it wasn't firing on 1 and 2 and had a rough idle (but it could get low, around 700 rpm).

It would fire on 1 and 2 if the rpms went higher, but not at idle.

Tested the intake manifold with starter fluid and it had a massive leak. Thought that was the issue, but after replacing it we just have a much smoother sounding misfire on 1 and 2 at idle lol.

So we rebuilt the carb. Same thing. Just a smoother misfire on 1 and 2. No misfire at higher rpms. Except now it won't idle below like 1200 rpm.

Tested the fuel solenoid on the carb. It clicks on when the ignition is turned on. Is it really that simple to diagnose?

Something that was happening from the beginning was a battery low voltage light on at idle... Which is making me suspect the alternator not producing enough power for the ignition system to fire well. That's my theory. Have to wait until Thursday to test it out. Has anyone heard of a weak alternator causing misfires? I know that some ignition systems run fine on battery power. Maybe this truck doesn't?
 
Joined
Jul 20, 2021
Messages
8
Location
Grass Valley, CA
Visit site
Howdy guys,

Bought an 87 FJ 60 and inherited some problems. When we got it running it wasn't firing on 1 and 2 and had a rough idle (but it could get low, around 700 rpm).

It would fire on 1 and 2 if the rpms went higher, but not at idle.

Tested the intake manifold with starter fluid and it had a massive leak. Thought that was the issue, but after replacing it we just have a much smoother sounding misfire on 1 and 2 at idle lol.

So we rebuilt the carb. Same thing. Just a smoother misfire on 1 and 2. No misfire at higher rpms. Except now it won't idle below like 1200 rpm.

Tested the fuel solenoid on the carb. It clicks on when the ignition is turned on. Is it really that simple to diagnose?

Something that was happening from the beginning was a battery low voltage light on at idle... Which is making me suspect the alternator not producing enough power for the ignition system to fire well. That's my theory. Have to wait until Thursday to test it out. Has anyone heard of a weak alternator causing misfires? I know that some ignition systems run fine on battery power. Maybe this truck doesn't?
Forgot to mention. It has 15 lbs of vacuum and new gas out of a bucket.
 

OSS

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Jun 30, 2017
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If it's an actual misfire on 1 and 2 where there isn't a spark, that's gotta be a distributor, spark plug or spark plug wire problem. Heck, maybe just the distributor cap needs to be replaced.
 
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Jan 4, 2011
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What brand spark plugs does it have, what’s the gap set to. Have the cap, rotor, and wires all been replaced?

these trucks are know for intake and exhaust and EGR leaks that will cause lots of idle problems. Mine didn’t idle until I redid the intake and exhaust with machine work and all new gaskets, sealing rings, and hardware.
 

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