[DonAltman3]

Now if I could get some help totaly removing the smog pump and most of the misc. vaccum lines after I am done doing this mod I would be set.. does anyone have a write up on that?

Mine is a 80-81 cj5 4.2

[tuffie226]

Quick question. I finally attempted the nutter / luckycheesehead bypass tonight and ran into an issue. When I went to disconnect the vacuum hose that runs to the dizzy, the other port at the "V" shaped tee was capped off also, but in the above pics, there appears to be a line running to somewhere. So I now have both of those ports capped off, but does the 2nd port need a line running somewhere?

Anyway, I moved on from that and finished the bypass, and I still couldn't really get the engine to hold an idle. I worked with the timing light to tell that I was keeping the rpm's at about 680 when I set it to 8 degrees. I plan on searching to try and find topics about setting the idle on the carb and all that, and I have the parts to attempt to do the Team Rich upgrade tomorrow, so I am just wondering if it sounds like I am on track, or should the Heep be keeping an idle better now with just that much done.

[79cherokee]

Ok, has anyone done this on an 84 CJ7 with a 2.5 4 cyl? I assume it is basically the same except I have a carter 1bbl. I have an ecm and the same ignition module as the 258.

[Mike Romain]

Originally Posted by 79cherokee

Ok, has anyone done this on an 84 CJ7 with a 2.5 4 cyl? I assume it is basically the same except I have a carter 1bbl. I have an ecm and the same ignition module as the 258.

I have no first hand experience with the 4 banger but have 'talked' online with folks that have done it. They did not seem to have trouble.

The only gotcha is the ability to set the mix on the carb. I am guessing you have access to the carb mix screw down front or can get the cover/plug off it?

Other than that it was the same with the wires and the timing adjust needed. As I have mentioned here and there, i prefer to use two new wires when doing this job, rather than mess inside an old wiring harness.

[Truck633]

Originally Posted by limegreenCJ7
Are there any negatives to the nutter bypass?


YES!!!!

ITS STILL A CARB!!!! Carbs became obsolete in the 70's, even the best carb cant handle rocky, bumpy steep inclines...which leads to stalls and restarts and broken parts! Do whatever it takes to get fuel injection!!! The difference will blow you away

Tom

[Mike Romain]

Originally Posted by Truck633

Originally Posted by limegreenCJ7
Are there any negatives to the nutter bypass?


YES!!!!

ITS STILL A CARB!!!! Carbs became obsolete in the 70's, even the best carb cant handle rocky, bumpy steep inclines...which leads to stalls and restarts and broken parts! Do whatever it takes to get fuel injection!!! The difference will blow you away

Tom

LOL!

Properly tuned, the carb runs well enough for us, we run sand pit and ravine walls with our 258's and go until its so steep the tires start chewing in, while holding a 'nice' 450 rpm. Mine has never stalled from angles. My friends that have tuned their carbs with me around also run these pit walls and they don't stall out either.

You have to get the float right 'and' use two freaking wrenches when putting on the gas line so you don't wreck the float setting by compressing that easily compressed 'fat' gasket washer on the needle seat fitting the gas line screws into.

FI is also a compromise that cannot match a properly tuned carb for gas mileage. Yes, with gas prices like they are and the need to pass an emissions sniffer, my carb gets a major tune at least every two years so it gets 22 mpg highway (under 65 mph) and passes the emissions sniffer with low numbers.

[79cherokee]

Originally Posted by Mike Romain

I have no first hand experience with the 4 banger but have 'talked' online with folks that have done it. They did not seem to have trouble.

The only gotcha is the ability to set the mix on the carb. I am guessing you have access to the carb mix screw down front or can get the cover/plug off it?

Other than that it was the same with the wires and the timing adjust needed. As I have mentioned here and there, i prefer to use two new wires when doing this job, rather than mess inside an old wiring harness.

My carb adjustment screws are in the open, easy to get to. So, I do I understand this by pass correctly that the ecm will still be present, just no juice to it or juice to it but not able to adjust timing and carb? Couldn't the whole emission system be scraped at that point? all the crazy vac lines and sensors, and the ecm itself?

[foggybottombob]

I have the Chevy HEI distributor on my 258 already. I made that change so long ago that I can't remember what the original wiring looked like. The HEI has the purple and orange wires going from one part of the disty to another. I assume that one end of the wires go to the control module inside the disty. What part of the bypass wiring can I do with the HEI distributor installed? Does anyone know? I no longer have the old orange and purple wires from the firewall to the distributor.

[Mike Romain]

Originally Posted by 79cherokee

My carb adjustment screws are in the open, easy to get to. So, I do I understand this by pass correctly that the ecm will still be present, just no juice to it or juice to it but not able to adjust timing and carb? Couldn't the whole emission system be scraped at that point? all the crazy vac lines and sensors, and the ecm itself?

On the 258, the harnesses share some wiring. the reverse lights for one. In theory folks just leave this one plug and cut the computer harness away from it so only the Jeep wires are left in a wide flat plug.

On the YJ, the tach comes from the computer so it has to be switched to the coil, don't know on either 4 banger, but the CJ 258 has an inline tach, not a pickup tach.

But all the rest of the emissions stuff is basically scrap once the computer is sleeping.

I have had to pass the emissions sniffer still and like my engine running right so I left the basics in, the air filter controls for hot air on a cold start, the PCV system and gas tank vent (charcoal canister) and EGR. The EGR needs a delay valve that is someplace in your plumbing to run correctly or you can get hesitations.

I also moved my distributor advance over to 'ported' signal so it advances with the gas pedal more or less.

[ajbjeeper28]

ok...when i did this nutter bypass i ran into two problems i was missing 2 vacume lines so i only have the vacume from the distributer to the side of the carb, and those two biger ones on the same side of the carb...are the other two important? also my jeeps a 87 yj...could it be that its set up a litle bit differnt than the cj?

[Fireman435]

ok guys ,just bought a 90 Jeep 258 ,just bought a chevy straight 6 Hei....the gear off the jeep is slightly bigger than the GM hei shaft...what do you do"? I also just bolted on a Ford 2bl Carb. does that allow me to eliminate the comp.?? Thanks email me at fords4brent@sbcglobal.net thanks Brent

[Mike Romain]

Originally Posted by Fireman435

I also just bolted on a Ford 2bl Carb. does that allow me to eliminate the comp.??

I can't help on the gear but yes, the computer can now be put to sleep although why you would go with a Ford carb vs the Carter-Weber that was on there.....

[ctm]

fireman435 I already answered your gear question in the other Nutter thread

http://www.jeepforum.com/forum/f12/nutter-bypass-problems-515180/index3.html

[jfite]

Hey with the stepper motor off, how do you adjust the pins? I'm a noob! Thanks.

[Mike Romain]

Originally Posted by jfite

Hey with the stepper motor off, how do you adjust the pins? I'm a noob! Thanks.

The center post of the motor will move in steps. I think the right place for the pins is on the step that first captures the pins between the backboard and the side of the stepper motor. So when the board just goes below the lip, that should do it.

This should have the pins with their shoulder about 1/8" from the back wall.