timing after desmog

[bdbaker]

hey, i have a 84 fj60. I have plugged the air rail holes, taken out the smog pump, put a rebuilt carb on and givin it a complete tune up. All of the gaps on the plugs are fine, and the spark plug wires are all on fine. the question is that it still runs a little rough. I can't get it to idle well. If the idle is set low then it will stall while driving when i come to a stop, and when i set the idle higher the engine does not want to stop running when i try to turn it off. I'm thinking that the timing is off but i have no idea what it should be after a desmog. Any help on how much to adjust the timing after a desmog would be a great help, or any other ideas on what could be causing this.

P.S. as far as i can tell no vacuum leaks or hoses disconnected, been over them many times

 

[Dave-T]

I would adjust the timing the same way you would before the desmog. Stock timing is 7 degrees. Some report performance gains after advancing the timing a bit.

 

[bdbaker]

thanks, gonna try that, hope it helps

 

[jasheehan]

If your distributor hasn't been "recurved," then you'll likely have to retard (I believe) your timing to get rid of auto-ignition. This is because you combustion is slightly more efficient without the exhaust gases that are no longer being pumped into your intake. If you recurve your dizzy, then you should be able to run at the normal 7 degrees BTDC.

 

[Dirty Toad]

I did the recurve and am running about 10 degrees BTDC. She runs smoother than ever before, but it is still a 2F and as you know, tractors don't run perfectly smooth.

 

[Kavik]

I did the recurve and am running about 10 degrees BTDC. She runs smoother than ever before, but it is still a 2F and as you know, tractors don't run perfectly smooth.

Ditto...desmog, recurve, 10-11 deg adv, valve adj = good running tractor motor

 

[FJ40Jim]

Generally, the timing being retarded or advanced by five degrees will have no effect on idle quality. A rough idle is cylinder(s) misfiring at idle. If those cylinders run better at higher throttle positions, then the problem is probably not ignition, which has the easiest job at idle. More likely an overall lean condition, or a lean cylinder(s).

HTH

 

[fliphkd778]

Other than having Jim C. do the recurve, is there another way to recurve a dizzy?

 

[FJ40Jim]

There is only one way to recurve the dissy:

Modify the springs/weights/governor pin/vac advancer as necessary.

 

[cfdlighthouse]

Generally, the timing being retarded or advanced by five degrees will have no effect on idle quality. A rough idle is cylinder(s) misfiring at idle. If those cylinders run better at higher throttle positions, then the problem is probably not ignition, which has the easiest job at idle. More likely an overall lean condition, or a lean cylinder(s).

HTH

not to hijack but if you have a lean cylinder(s) is there a solution without mill and valve work???

Thanks

 

[FJ40Jim]

Yes, fix the cause of the leanness.
Replace bad manifold gasket, repair defective emissions system, replace leaky brake booster, etc.

 

[cfdlighthouse]

Yes, fix the cause of the leanness.
Replace bad manifold gasket, repair defective emissions system, replace leaky brake booster, etc.

thanks

 

[Pighead]

P.S. as far as i can tell no vacuum leaks or hoses disconnected, been over them many times

So, what is your manifold vacuum? In "/Hg? I was gonna say you've got a vacuum leak...
Does it run better with a little choke?