Marine1Texas

basically you need to start from power and work to the pump with a tester. check power in to the fuel pump relay also checking the working of the relay. If you do have power at the relay then jump it over. if the pump comes on, it would be part of the ignition not switching the relay on. If the pump does not come on, then you need to trace the power to the pump from relay. At this point if pump does not come one you need to make sure your ground are good for your pump. Check wiring on connector near pump, and the ground on rear left tail light.

looks like a great idea! With a plate like that it would make a HO intake with the throttle body bolt up very nice and simple for the renix 4.0's.

if the lever is correct your not in 4wd. It is a physical shifting on transfer case. however that does not mean your front axle is free moving and still engaged turning the front drive shaft. I have never had this happen, however 1st steps would to check the vacuum lines engage that shift motor on the front axle. stuck in lock position. More should chime in to give better information.

sounds like you have some issues in the fuse box. I bet the contacts on the back of the box have started to corrode and this will not be the last issue if it has. make sure you are not dripping clutch fluid, it can make all kind of funky issues thru the fuse box.

yes it is basically a rubber oring. A regulator that is faulty would cause extra pressure, but should not cause the oring to fail. Like any other synthetic rubber life span with gas and chemicals is not forever! However a good time to replace the oring and maybe the regulator. Make sure your orings on injectors are in good shape too. you can get them in a pack from most auto parts store!

did you check you ignition? Sounds like nothing is getting turned on

good find, looks like a machinist that likes his 4.0's....

Awesome to hear it. What kit did you get? Motorcraft 2100 carb is a good choice!

My 87 long bed, and 88 short bed both can be changed by not dropping tank.

If you can't find east replacement, cut the old one off and weld a new bolt on it. I done this before on a older chevy. Just making sure to use a good strong bolt. However I am sure you can get a replacement bracket! http://www.oemautopartsandaccessories.com/catalog/parts/list/system/suspension/g/rear-suspension/s/suspension-components/v/jeep-comanche-1988/vtec/99434/

As Eagle said your CPS! Have you installed the tranny yet with the cps bolted on? CPS needed for ECU to let it fire. Before you put cps on, do the mode, to get the advanced timing for better mpg on highway!

The aluminum tank should last for a very long time . I still have a 29 year old tank my self, it has never blown or cracked. Kind of strange how some last and others don't. If mine ever does go, I would get the aluminum tank!

Agreed the battery and the alternator still have to support the power requirement. However with Relay's you can lighten the load to the switch's and the under engineered electrical system like with my 2 renix jeeps. The Grounding system is not great at all. I also notice extreme loads on positive wires and undersize wires as well. Keeping things simple with a relay setup is also required, because as you try to lessen the load thru a bad designed electrical system, you increase the amount of remembering where everything go's to. As Eagle stated Voltage drop! With volt drop you will then require higher amps to keep up, this puts strain on the light weight wiring. So with high amps items like, fans, blowers, headlights, 12 volt accessories plug, and even a high output radio, relays are key....

Relays are awesome thing you can use to lighten load on electric system. I use two relays for my head lights that connect direct to battery then the switch from head light turn trips the relay on. I do use one for the fan blower, 12 volt utility connection and one that will allow me to turn electric fan on by switch with out a/c clutch engaging.

In summer I use 15W50 mobile one synthetic and in winter I use 0W40 mobile one synthetic. With 240K on 1987 4.0 original engine and I have yet to see any burning oil since started using it in the early 1990's. I will do the same with my new MJ a 88 with new 4.6 crate engine.

I know the efi will run with out the dizzy hooked up with a HEI, however I don't know if the ecu can calculate the timing curve on advanced timing with out sensor information. Unlike a vacuum advanced timing like a HEI has, you would loose mpg while traveling at highway speeds or under light load. There is no info to let your ecu know it is ok to advance timing because your RPM's are increasing under a light load. You only have mechanical timing advance. However a HEI system that has a vacuum advanced, you can get as close to max advance as possible. I my self when using a HEI with a carb set start around 9 degrees on the 258, then I adjust up the timing to get the best vacuum before it drops. Then I will retard timing just enough to drop rpms 75 to 100. That is ported. However you can do the same way but needs a little more tuning when you use manifold. Most of the HEI's I have use have a 16 degree mechanical timing, with 6 to 10 advance vacuum timing. So setting right around 9 to 11 you can get as close to 36 as possible.

That is a different way to get the same number :) I have never used that way to get it, however now I know two ways to calculate it.

Yes that would of been such a increase all the way around, and offroading would have improved a lot I bet

yes the Weber 38mm DGAS has this single Venturis like the old AFB's With high and low 4 barrel. The older Weber 38mm that made pre 1986 did not have. I guess when they updated the design they had in mind what you thinking. I guess the people upgrading from a single barrel to 2 barrel noticed difference in mpg. The Rochester’s 2G had it too, but did not work as well.

Like above said, if you want to spend the money you can get much better then the Renix. Renix is very good, but just had design flaws that you have to make sure grounds are kep in check

From having a few 258's in the past with carbs. So a Holley 390 CFM four-barrel, or a jetted Weber 38-series would work great . The 258 or 4.2 carb need would be at least 373 CFM is needed to reach max rpm. So a 375 to 400 CFM will do. A 4.0 would run very well with a Weber 38 Two barrel, no need for more then 2 barrels because all needed is 350 CFM, which is the same a EFI pulls at max RPM. I have to add, Dual SU carbs would look cool, but it would work much better on a split intake system. Since they mainly made for old British cars and Volvos. Basically if I remember right you take the cubic inch of your engine and divide by 2. then you take your redline limit, or max RPM and divide by 1728 and you get CFM you need. So a 4.0 is with a redline of 5000 rpms you get 350 CFM. Rochester’s 2G from Chevy 283 V8, Carter BBD from 318 V8, 2300 Holley from the 266 V8 are my picks for old style 2 barrel carbs. I have run all of these and work well on the 258's I have tried the Rochester Quadrajets, and Federal Mogul 4 barrel carbs. They are not my top pick to put on a 258 or smaller. They don't idle very well. Basicly I am saying anything from 350 to 400 CFM would be a good fitting carb. Now I really like Holly , but the Weber 38 DGAS 2 barrel Carb is very well made carb and you can find them very easy for jeeps.

I have read someone put a 4.2 intake on and used a 4.0 header with it. They had to mode the 4.2 intake, by blocking the water jacket tubes going from head to intake, also small mod to block the injector holes. they mounted a 4br carter on it.

where you get it Jeepjeff859? and what about the price wise? From what I can see the design of the EFI intake is not suited for air and gas mixing chamber, but hey if it is cheaper then maybe it is a good option. What used to plug the injector hole?

Clifford sales complete kit for the 4.0 to convert to carb. http://www.shop.cliffordperformance.net/68-Jeep-40-242-Combination-68J242.htm $1,257.00 Now the kit does not cover the HEI dizzy. you would have to get a HEI dizzy, this one is not bad complete for $149.97 http://www.summitracing.com/parts/SUM-850047 You would also have to either do a dual exhaust or connect the 2 pipes in to one. Now remember unless your exempt this will not pass smog or State inspection. Here in Texas only 1991's and below are exempt or 25 years and older. Off-roading will be find with this kit as long as your not doing steep rock crawling. you can get 21 mpg with that Weber 38 DGAS, as long as your dizzy is tuned right with your carb. People will all say why go back in time with a carb, agree or disagree just giving the info for what you asked. This link is the standard info on how to do it http://www.4wdmechanix.com/How-to-Tuning-the-Carbureted-Jeep-Inline-Six-Stroker-Motor?r=1. This article is more for the 4.2 but much applies for the 4.0 on converting.

A couple of small things, have you done the Cruiser Tips? c101 box can cause many issues! I took mine out and wired direct. I did not see if AT or MT. If MT you can get clutch fluid that spills over and runs down back of fuse box. can cause all kind of funky problems with no power going thru fuses to where it needs to go, corroding the connections at the fuse box