My Desmog Thread (9 Viewers)

[hward1]

Do these things:
Disconnect & plug vac hose to disty advance. Adjust the ignition timing to 7-10*BTDC (BB at the pointer or in the bottom part of the window.) Reconnect hose.
Adjust AF mixture for best idle quality/highest RPM/highest vacuum.
Adjust idle speed to desired number w/ engine at operating temp.
Re-adjust idle mixture.

1 - going to set timing correct with hose plugged and not distributor plugged -

2 - before i mess with the carb settings that you set for me on the desmog carb -- want to make sure you know its the one i got from you

3 - and dont worry about computer for the desmog - correct

 

[hward1]

do i worry about the emissions computer for the desmog

 

[hward1]

Do these things:
Disconnect & plug vac hose to disty advance. Adjust the ignition timing to 7-10*BTDC (BB at the pointer or in the bottom part of the window.) Reconnect hose.
Adjust AF mixture for best idle quality/highest RPM/highest vacuum.
Adjust idle speed to desired number w/ engine at operating temp.
Re-adjust idle mixture.

still having trouble ----- on dizzy the 2 vacuum ports coming off - which one goes back to the carb the one closet to dizzy or the other one - i suppose to have one going back to the breather does it have be going somewhere or can it be a open hose line

how do i plug the hoses and ports for timing on the dizzy

 

[GeologistFelix]

Primary diaphragm on the dizzy is the one with the vacuum inlet closest to the dizzy body; secondary is the smaller one further out.

 

[hward1]

which one -- primary or secondary on dizzy is left open and going to the breather at a eastern NC altitude - thanks

 

[hward1]

the new Jim C carb/dizzy recurve installed - trying to hook up the hoses correct -- its for a 87 no HAC desmog going by diagram - all of the other desmog stuff completed - tried to start today and carb popped smoke --

troubles: need help

1 - primary (closest one to dist.) have it going to primary on carb(would that be correct)
2 - hi altitude (dist.) ? where does this go (pics dont show complete routes
3 - ac valve thing by drivers fender - which line goes on top - which one on bottom
4 - gas filter on intake manifold - two lines where do they go

5 - Charcoal canister hose swap on the EVAP system to keep gas tank pressure from building (have not done this)
6 - when i try to crank it again - do you hold the gas pedal down or pump it --

1 - im still confused i guess -- first question yes or no - thanks (because i have it set up where the secondary is going to carb)

 

[FJ40Jim]

Try it w/ vac connected to primary diaphragm. If the dissy is stock, chances are spark knock will be observed in the 1800-2200RPM range. If so, then switch down to vac connected to HAC diaphragm.

 

[hward1]

thanks again for the help --

1 - the dizzy is the one you recurved for me -- i dont have the HAC hooked up -
2 - im only getting 13 vacuum (needle starts at about 15 then goes and stays on around 13-14 doesnt bounce) at gas filter on intake with all this done - (jim c dizzy recurve, jim c desmog carb, planed manifolds and full desmog, valves checked, cat removed new muffler) i dont know what to do

 

[hward1]

UPDATE: (also read above)

so i did a check at the brake booster instead of the gas filter on the intake -- i get a some what steady 19.5 vacuum reading now (first it started at 20 and dropped to 19.5)

i feel some better -- not sure about the drop

1 - noticed site glass level was near bottom but after starting it went to half full
2 - brake booster reading 19.5 - gas filter reading around 14
3 - i did get a small backfire once while driving and coasting (drove for about 15 minutes) - (i do know where i cut off the part on the exhaust pipe i have a small leak where i tried to weld it shut
4 - also seems to have a unsteady exhaust sound (a little bit) magniflow muffler installed
5 - doest seem to ping while driving hard - (only flat around here) but i did have it where it was pinging before while trying to adjust)


6- any ideas or does it run like it should (only one i have ever heard run) - i dont want it to run lean (i dont think i did the mixture part exactly correct - hard to do while it hot) (try and listen to see if anything is off) - really thanks to this site i have made it this far

http://s134.photobucket.com/user/hward1/media/Land Crusier/MOV05967.mp4.html (vacuum)(notice needle moves some)
http://s134.photobucket.com/user/hward1/media/Land Crusier/MOV05968.mp4.html (rpm)



havnt hooked up ac hoses yet -- dont have a a/c

left open but i guess i need to get a longer hose and put it to the breather - how critical is this hose left open -- the other hose goes to the carb (can see on the pic above where it goes to the carb)

 

[FJ60Cam]

On the last pic - you can just cap it on the dizzy. Or don't. It won't leak any vacuum.

 

[hward1]

ok thanks

 

[hward1]

also getting small popping out the tail pipe while letting off of the gas driving ( i do have a small pin hole leak on the exhaust about 3 ft down where i did the desmog cut )

 

[hward1]

messed with the carb the truck sounds better while driving (out of the tailpipe)-- i need a rpm gauge to adjust the rpms correctly i think-- trying to just use the vacuum gauge i cant seem to get it right - when i adjust the carb it takes me reving the engine so it adjusts some (not sure why this is or maybe its normal for a rebuilt carb) (which tachometer is good to use)(also maybe someone could take a look at the pics to make sure i have the desmog set up correct) i have now capped the open hose off dizzy-i have no a/c as of yet hooked up / no HAC as of yet -- located at sea level

 

[GeologistFelix]

The linkage can be a little bit sticky, so you have to give it a little jiggling (in the form of opening and closing the throttle by 'revving' the engine a bit) for idle/etc. adjustments to 'take.'

Also, the pop from the tailpipe is very likely to be related to the hole in your exhaust. I had the same thing (only bigger, I suspect) because the connection between my manifold and downpipe was loose.

 

[gregnash]

I actually found your carb issue well explained the other day. Basically, your carb is a system that takes a moment to figure out what you did due to the "analog" mixing of items. So when you make carb adjustments, use the linkage and revv the engine a few times to see that the change takes. Your main focus with the vacuum gauge should be to see that the adjustments keep you at 20" of vacuum or close there of when idling. From there you should adjust the timing and idle, again giving the carb a minute to "figure out" what just happened.

 

[FJ60Cam]

Maybe check the timing, too, to see if helps with the popping.

 

[hward1]

The linkage can be a little bit sticky, so you have to give it a little jiggling (in the form of opening and closing the throttle by 'revving' the engine a bit) for idle/etc. adjustments to 'take.'

Also, the pop from the tailpipe is very likely to be related to the hole in your exhaust. I had the same thing (only bigger, I suspect) because the connection between my manifold and downpipe was loose.

thanks -- i think my whole truck needs a little jiggling

 

[7StringerFJ60]

timing and egr delete

Try it w/ vac connected to primary diaphragm. If the dissy is stock, chances are spark knock will be observed in the 1800-2200RPM range. If so, then switch down to vac connected to HAC diaphragm.

Jim, first off, thank you so much for your time and extremely valuable input.

I recently discovered problems with my EGR on my 85 FJ60 and decided to delete it and replace with the plate kit from MAF. Im glad i went the delete route as the issue with stumbling is gone and under normal driving conditions i keep my foot out of the skinny pedal a lot more..so hopefully that will translate into better mileage..we'll see. The only drawback is that i think im getting a bit of spark knock right in the rpm range you described. (Its almost non existent when im light on the throttle and intensifies with more throttle). Other then that the thing runs way better than i expected.

I will connect my main advance line to the HAC port to see if that fixes the issue, but I live at 4900ft and will drive anywhere from 3500-8500ft so i would like to keep the functionality of the HAC system. I think a recurve of the dizzy is the best route to go. Can I play around with different springs for the mechanical advance? What else is involved?

 

[FJ40Jim]

There are springs and a governor bushing. The thickness of the bushing controls the total advance, springs control the slope of the advance curve.

 

[7StringerFJ60]

Ah i see. All is well post 2400 rpm i assume the total advance is fine, i just want it to happen later correct? ...im assuming the springs are the solution to that.
Oh! and i tried out hooking my primary advance to my HAC port and no change happened. (Honestly though, taking a look at the rest of my vac lines..they are ancient! ... and i really think i will complete your full desmog before messin around with dizzy springs)