setting idle speed 87 fj60 (1 Viewer)

[hward1]

setting idle speed

1 - adjusted mixture to highest rpm
2 - adjusted idle speed to 650 rpm

3 - ??? now what do i do again to the idle mixture and why

thanks

 

[GLTHFJ60]

It's called the lean drop test. You do this to find the optimal air/fuel mixture at idle, which dictates the air/fuel mixture for the entire RPM range.

You repeat steps 1 and 2 until adjusting the mixture screw doesn't do anything other than lower RPM when the motor is idling at 650 rpm. Technically you should also have a vacuum gauge hooked up to manifold vacuum as well and you adjust to max vacuum as well. It's a bit of give and take, but you'll find where the motor sounds best at idle and has the best throttle response off-idle.

 

[hward1]

thank you - i need a vacuum gauge

 

[dorcom]

thank you - i need a vacuum gauge

Harborfreight: US General $ 9.95 (sale)

 

[GLTHFJ60]

Harborfreight: US General $ 9.95 (sale)

Yup, or auto zone, or advance auto parts. They should all have that in stock.

 

[FJ40Jim]

Or use a tach.
Both the tach and vac gage will peak at best idle quality.

The lean drop method is used to get the idle mix lean enough to pass emissions test.

Set the idle mixture to peak RPM/vac for best idle quality & driveability.

 

[GLTHFJ60]

Or use a tach.
Both the tach and vac gage will peak at best idle quality.

The lean drop method is used to get the idle mix lean enough to pass emissions test.

Set the idle mixture to peak RPM/vac for best idle quality & driveability.

Gotcha, thanks for the clarification Jim

Would the vacuum gauge be a more accurate way to find best idle quality than the factory tachometer?

 

[dorcom]

Would the vacuum gauge be a more accurate way to find best idle quality than the factory tachometer?

In my personal experience a good and large vac gauge is a revelation. The best versatile measuring tool!

It astounds me what you can see and read from it!
Ignition timing, idle mixture, misfires, valve issue, alternator load, altitude/elevation, weather, humidity, drive style* and so on.

I've got mine permanently installed and learned that a *lower gear does not always mean more efficiency! In fact the 5th gear turns out to be no fuel saver at all, just a rpm saver.

 

[Michael Hanson]

Dorcom, Where exactly did you mount the vacuum hose on your fj-60 manifold? I always use mine and take it off. Thanks, Mike

 

[The Machinist]

Dorcom, Where exactly did you mount the vacuum hose on your fj-60 manifold? I always use mine and take it off. Thanks, Mike

I've got mine T'ed off of the "Gas Filter" that is screwed into the top of the intake manifold. It's that thing with the 3 hoses coming out of it. (im smog equipped fwiw)

 

[dorcom]

Dorcom, Where exactly did you mount the vacuum hose on your fj-60 manifold? I always use mine and take it off. Thanks, Mike

On the small vac port blow the carb base.
The one that goes to the VCV EVAP.
I simply added a T (Orbit Garden Drip,[Home Depot] great stuff for vac lines rigging!)

 

[The Machinist]

Im using the exact same drip system T's on mine! I thought I was the only one....

 

[dorcom]

Im using the exact same drip system T's on mine! I thought I was the only one....

Great minds think alike...

 

[gregnash]

Darrell for yours, which of the ports did you use or does it really matter?

 

[FJ40Jim]

Gotcha, thanks for the clarification Jim

Would the vacuum gauge be a more accurate way to find best idle quality than the factory tachometer?

Yes. The factory tach is just for an approximate idea of RPM. I use a digital tune-up tach that reads to the single digit so a change of 10 or 20 RPM is easily seen.

 

[hward1]

finally got a vacuum gauge - so for a JIM C desmog so i hook it up to the gas filter on the manifold (removing one of the plugs on the filter and leaving the one line hooked up on the gas filter - so one would be still used one plugged and one hooked to the vacuum gauge)

is this correct


hooked up like this -- gauge steady reading is 14 @ about 750 rpm (on dash) at idel - i think i got the wrong gauge no rpms on gauge just vacuum and fuel pump reading -- also it backfired going down the road to warm it up - exhaust sounds like bubbles poping when let off gas

 

[hward1]

could it be this Improper idle mixture floats slowly plus or minus 1 ½ to 2 ½ inches or timing is off some -- when i watched the gauge it started at 15 and then went to around 14



found this


CONDITION INDICATION
readings are at idle unless otherwise stated. Gauge readings are in inches
1. Normal Steady at 15 to 21
........................
Drops to 2, then rises to 25 when throttle pedal is rapidly depressed then released.
2. Intake leak Low steady reading less than 10
3. Head gasket leak Gauge floats between 5 and 19
4. Improper idle mixture floats slowly plus or minus 1 ½ to 2 ½ inches
5. Small spark gap or defective points slight float plus or minus 1 to 1½ inches
6. Late ignition timing Approx 2 inches below normal idle
7. Late valve timing 4 to 8 inches below normal idle
8. Worn valve guides Oscillates plus or minus 2
9. Weak valve springs Violent oscillation (plus or minus 5 inches) as rpm increases. Often steady at idle.
10. Sticking valves Normally steady, will intermittently flick downward about 4 inches
11. Leaky valve Regular drop about 2 inches
12. Burned or warped valve Regular, evenly spaced down-scale flick approx 4 inches
13. Worn rings/ diluted oil Drops to 0, then rises to approx 18 when throttle is rapidly depressed then released
14. Restricted exhaust system Normal when first started. Drops

 

[hward1]

so to set timing for desmog --- harbor freight timing light but has the dial on the back - i had it at zero --

1 - unplug 1st hose on dizzy and plug it -- ? do you put another hose on dizzy to plug it off now
2 - nothing on second plug left open -- ? so do i add a hose and plug that one

 

[dorcom]

so to set timing for desmog --- harbor freight timing light but has the dial on the back - i had it at zero --

1 - unplug 1st hose on dizzy and plug it -- ? do you put another hose on dizzy to plug it off now
2 - nothing on second plug left open -- ? so do i add a hose and plug that one

-Plug both hoses
-set adj timing light to 7 BTDC (better 6 to be safe)
-make sure you don't accidentally turn the timing button!
-Point at flywheel window

With the advance set 6 or 7 on the timing lite you should have the TOC mark on the flywheel line up with the reference pin.

If you have a conventional fix timing lite it's the small hole next to to the TDC mark that has to line up.

 

[gregnash]

You timing marks on your fly wheel may be hard to see so I would suggest removing the flywheel inspection cover (a few 17mm bolts if I remember correctly) and get some white out or bright color paint and paint both marks. There will be a like and a hole/bb, the line is TDC and the hole/bb is 7* BTDC (if I remember correctly).