New to the forum and to a partially restored '84 Fj60. I recently replaced distributor, rotor, and spark plugs. Now 250 miles from this, the last two times I have shut off the truck, it was "dieseling". I checked my old spark plugs and they were so short they would not gap. My '84 manual calls for .031 inches or .8mm. I will check my gap on new ones and adjust this evening if necessary, but before I did, I wanted to check if this is what most people are running with theirs and if something else may be causing the dieseling besides the spark plugs. Lastly, in the previous 500 miles I have driven the truck since I bought it, it never did this.
Correct Spark Plug Gap for 2F (1 Viewer)
- Thread starter BamaFJ
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.031 is the correct gap for the SP
As for dieseling, one primary suspect is the operation of the Fuel Cut Solenoid (connected with that green plug on the carb).
The procedure how to check that is on pg. 3-44 in the emissions manual. Easy to see if it is working or not.
As for dieseling, one primary suspect is the operation of the Fuel Cut Solenoid (connected with that green plug on the carb).
The procedure how to check that is on pg. 3-44 in the emissions manual. Easy to see if it is working or not.
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Ok so I yanked my old spark plugs and bought all new...didn’t even think about anything just purchased and installed....now thank god I saved the old ones that came with the truck when I purchased it, I noticed 2 of the spark plugs were smaller depth in regards to their threading. I’ll attach a pic...can anyone help me out with which ones need the smaller? Or what the heck this previous owner was doing because my engine is definitely NOT running on all cylinders and I know it’s the spark plugs bec they wreak of gasoline and are burned to crap
If you're using the Toyota spark plugs, the gap is already set close enough out of the box to just screw them in without checking.
After 30 years I never got a Toyota plug that was gapped significantly off of spec.
But spark plug gapping (bending) tools and feelers are available at any auto parts store - so no harm in checking.
Normally all the spark plugs are identical for the 6 cylinders and all gapped the same. If you've got different plugs in different cylinders, maybe the PO just threw in whatever he could find with no grand plan in mind.
After 30 years I never got a Toyota plug that was gapped significantly off of spec.
But spark plug gapping (bending) tools and feelers are available at any auto parts store - so no harm in checking.
Normally all the spark plugs are identical for the 6 cylinders and all gapped the same. If you've got different plugs in different cylinders, maybe the PO just threw in whatever he could find with no grand plan in mind.
True
See how the left most 2 have shorter threading than the the other 4 ... is that the previous owners mess up or what’s up with that? Anyone else experience that or everyone use to all 6 being the length of the 4 on the right? Again I have ‘76 40 series 2F
Pic is upside down so my description is incorrect but you can see what I’m talking about...
You could check and see if any of the spark plug ports in the head have been repaired with a helicoil.
Although, I’m going to guess someone had a 4 pack of plugs and got 2 more NGK plugs and didn’t look closely at what they were doing.
Although, I’m going to guess someone had a 4 pack of plugs and got 2 more NGK plugs and didn’t look closely at what they were doing.
Ok 
that’s what I was thinking but decided to ask everyone in case there was a reason
that’s what I was thinking but decided to ask everyone in case there was a reason
