Spark Plug Gap

[1991GXL80]

Hi all,

I run NGK plugs in my 3F-E. Last time I changed the plugs I did not adjust the "gap"and just used them with the off the shelf gap. The engine ran/runs well.

Today i adjusted the plugs to the 0.08 gap as per the FSM and the engine runs like sh!t... coughing/spluttering, ruff as all hell.

Changed the gap back to what it was off the shelf and engine back to normal.

Any ideas/thoughts here as to why the FSM gap run no good?

Cheers.
A.

 

[Ebag333]

Are the plugs in the same temp range as OEM?

 

[1991GXL80]

Yip..

 

[CJF]

Today i adjusted the plugs to the 0.08 gap as per the FSM.

I'm sitting here right now looking at page MA-4 of my FSM: Specification is 0.043 inches.

 

[jonheld]

I'm late and Curtis is correct as usual. Not sure what FSM you're looking at:
From my FSM

(c) Set the gap on the new plugs.​

Correct electrode gap: 1.1 mm (0.043 in.)
Recommended spark plugs: ND W 16EXR–U11​

NGK BPR5EY 11

 

[1991GXL80]

Rm1341 3f-e 88-92

See attached form RM1341 3F-E 88-92 sup.

 

[Frankencruiser]

What gap did they come set at? Are they standard plugs or some iridium or platinum plug?

 

[yohavos]

The FSM I've got for a 1FZE states .031 inches.


Don't have one for a 3FE, but I trust those guys.

Wonder why your publication would be different. I understand that's a Toyota Engine Service Manual you've got.

 

[breathed]

The original post states you set the spark plug gap to 0.08, but is that inches or millimeters?

 

[jonheld]

OK folks. Lets not confuse the issue here.

We're talking about a 3FE motor in an 80 Series correct?
That's NOT a 1FZ-FE in an 80 Series.
That's not even a 3FE in a 62 Series. A 3FE in a 62 has a different coil/igniter/ECU.

The correct spark plug gap for a 3FE in an 80 Series is as stated above by Curtis and myself. If you choose not to pay attention to that, it is certainly your prerogative. BUT, the fact that you set the plugs to your FJ62 FSM spec and the truck ran poorly should be a DEAD GIVEAWAY that it is INCORRECT.

 

[jonheld]

Also please notice the part numbers on the plugs stated in the FSM. They both have "11" at the end. That's 1.1 mm from the factory. While they are almost always spot on, I check them anyway. I've had to slightly adjust maybe 4 or 5 over the last 20 years.

 

[1991GXL80]

Thanks Jon, you have an amazing wealth of knowledge. Though I think you just need to work on the delivery, we're not all experts here, hence asking the questions on this forum.
Have a great day.

 

[jonheld]

Though I think you just need to work on the delivery

Yea, I get that alot. Depends on the time of day

 

[1991GXL80]

Cheers John, thanks for your input.