Is the green wire modification needed IF the FUEL CUT/DECEL VACUUM SWITCH is connected to the appropriate port on the carb (fuel cut port)?
Green Wire Mod question: (1 Viewer)
- Thread starter Rat Patrol
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What's the green wire mod ?
Spike,
I think he's talking about your nice pic.
https://forum.ih8mud.com/60-series-wagons/300513-fuel-cut-off-help-w-pictures.html#post4690240
I think he's talking about your nice pic.
https://forum.ih8mud.com/60-series-wagons/300513-fuel-cut-off-help-w-pictures.html#post4690240
Oh, that green wire mod...
The decel vacuum switch operates under certain parameters of engine vacuum and speed with a signal from the emissions computer, to close the ICS and lean out the mix on deacceleration, I imagine for emissions.
If you ground the WHITE wire (that why the 'green-wire' confusion) you by-pass the emission computer rendering the decel Vacuum switch inoperative because the ICS will always be on (open) as long as the ignition key is in the 'Run' position, energizing the ICS.
The decel vacuum switch operates under certain parameters of engine vacuum and speed with a signal from the emissions computer, to close the ICS and lean out the mix on deacceleration, I imagine for emissions.
If you ground the WHITE wire (that why the 'green-wire' confusion) you by-pass the emission computer rendering the decel Vacuum switch inoperative because the ICS will always be on (open) as long as the ignition key is in the 'Run' position, energizing the ICS.
Uh, what?
Do I want the the decel vacuum switch to be in-op? And do I want the ICS always to be on? IOW do I want to round the white wire coming out of the green thing if I'm de-smogging?
(Holy Crap this stuff is complicated and annoying! What were they thinking??)
1911
chupacabra
If your trucks idles just fine now, you don't have to bypass the emission "computer" control of the fuel cut solenoid as part of a de-smog, you can just leave the decel vacuum switch intact. The trouble a lot of folks have though, is that the emission "computer" (really just a printed circuit board with a few components on it) is cold-soldered by the factory and the soldered connection between the wiring harness plug and the circuit board typically cracks and makes an open circuit, where the FCS can't be grounded so that it opens and allows fuel into the idle circuit of the carb. When this happens, your truck will not idle at all without the choke open. To make matters even worse, it usually happens intermittently at first.
The solution to this problem is to either heat and re-flow the solder where the connector joins the circuit board on the emission computer, or to just bypass the emission computer by grounding the white wire from the FCS so that the FCS is always open when the ignition is on. The second option is by far the easiest and it works just fine. My 40 has been running that way for years and a ton of miles.
If you ground the white ICS wire your decel vac switch system will be in-op. You want the ICS to be on when the engine is running or truck won't idle because the idle circuit in the carb will be closed if the ICS were off. Search for ICS, this has been discussed many many many many times.
Ah. Thanks. I'm not sure if the computer is working or not. I'm not sure if it idles with the choke on or not as the choke doesn't work at present.
Matter of fact, the only thing I am sure of is that this smog crap was a bad idea that went way bad after the passage of 29 years. It's a hair-ripping-out kinda thing to deal with.
While I've got you, not to hijack the thread or anything, how do I remove all the HAC stuff and make the HAC constant on? I live at 7k' in the San Juans of CO and she's never gonna go much lower.
Thanks
Sorry if I'm reiterating things previously discussed but to paraphrase Jimmy Buffett, with all of my running and all of my cunning I've never come across the 'green wire mod' before and I've looked at most of the de-smog threads, maybe. There's a lot of them.
No such thing as ""Green wire mod". It's the white wire that is cut and grounded.
I'd leave the HAC stuff on and make sure it's functioning. But if you want to remove it and make sure the next guy who owns your truck curses your lineage, follow the desmog thread in the FAQ.
I live in CA so have never removed any of the smog stuff - I just have had to learn how it works to keep it working to get the smog nazis off my fenders.
I'd leave the HAC stuff on and make sure it's functioning. But if you want to remove it and make sure the next guy who owns your truck curses your lineage, follow the desmog thread in the FAQ.
I live in CA so have never removed any of the smog stuff - I just have had to learn how it works to keep it working to get the smog nazis off my fenders.
1911
chupacabra
The HAC system does two things: it advances the ignition timing an additional 6 degrees (when over 3,930' elevation), and it also bleeds air into and thus thins the mixture in the low and high-speed circuits in the carb. Assuming that your carb is properly jetted for your altitude in the first place, then you can take off the HAC valve, plug the ports on the carb it goes to, route the distributor sub-diaphragm advance vacuum line to the air cleaner, and advance your base timing another 6 degrees (which would be 13 degrees BTDC total). That is quite a bit of advance, but may work fine for your motor and altitude. What I would suggest rather is that you start at 10 degrees BTDC and advance the timing a little at a time, driving it up a steep hill after each trial, until it starts pinging under load (up the steep hill). At that point, back off (retard) the timing until it just doesn't ping under any circumstances. That will be the best timing and the most power and fuel economy for your exact truck and conditions.
I now know that it should be "The White Wire Mod," but the title of the thread is "Green Wire Mod," I was referencing that, hence the quotes.
If the HAC is functioning it's always in high altitude mode. Why have all that crap in the engine bay if it doesn't do anything?
There won't be another owner.
The PO did not follow the de-smog threads and it was half de-smogged with a hatchet when I got it. Everything that was hooked up was hooked up incorrectly, the thing barely ran when I got it. With help from the de-smog threads it now has power and delivers around 14 mpg if you drive it easy.
I'm reasonably certain the HAC is non-op and hooked up incorrectly. I'll not be buying any new parts for it. The clever little brass tubing manifold is all bent up and I'm pretty sure none of the tubes is where they're supposed to be, negating the utility of the published maps.
So my next project is to figure out the routing of the remaining vacuum lines--HAC/dizzy, A/C idle up, PCV, evap--and go direct with new rubber tubing, removing the brass thingie in the process and plugging all the unused vacuum lines at source and terminus.
The ultimate solution to the de-smog issue for me will be a GM TBI kit from Affordable Fuel Injection, DUI Dizzy and Man-a-free headers. I've seen that set-up on an FJ40 2F and it was very sano. Just waiting to build up the cash.
Thanks
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Sorry to hijack but just wanted to make sure this is appropriate. I'm doing an '86 2F from a 60 into a '64 FJ40. There is no computer so the Green/White wire mod was neccessary. It seems that since there is no longer a computer in the picture I could connect the "Vacuum S/W" to the positive "Fuel Cut Solenoid Valve"???
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If you're using a 60-series carb, there will be a white wire and green wire coming from the ICS in the carb. Cut the white wire at the green connector and put a ring terminal on it and ground it to a screw on the air horn, or any point on the carb. The green wire should get switched 12v power.
If you're running an earlier carb that has only one wire out of the IC Solenoid, the grounding is already there through the body of the ICS.
Vacuum switch is gone.
If you're running an earlier carb that has only one wire out of the IC Solenoid, the grounding is already there through the body of the ICS.
Vacuum switch is gone.
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Cool, thanks. By "switched" I'm assuming through the ignition (IE, positive connection on the coil?). The combination of both the engine swap & the P/O's de-smog has got me really shaking my head & testing my patients!!!
Yes, by switched I mean 12v to the ICS when the ignition switch is in the ON or run position. You want the power to cut when the ign is switched off - that's the point of the ICS, to kill the idle circuit and prevent "run-on" or dieseling.
