4.0 Head, MPFI, and Serpentine on my 82 258

[ThisGuyUKnow]

I am still having woEs with the darned fuel pump circuit. Everything seems to be in place and I have isolated the wire that is supposed to power the pump but the problem is when the key is turned on it only goes hot for a split second and then something( assuming the ECM) shuts down the circuit. It should run for a few seconds when he key is turned to on in order to primethe line with pressure. I posted in the 4.0 tech section of cjoffroad and some said I need to wire in the fuel pump resitor ballast and the fuel pump resister ballast bypass. Makes sense but they weren't with the harness I bought and I can"t find any snipped wires that might wire into these ballasts so
I may for the time being just run a "run" hot line to the pump and bypass the computer control for the pump but man I really wanted all the systems to run through the Cherokee harness and PDC

 

[ThisGuyUKnow]

Still no Luck. From what I can tell I have everything wired up. As soon as I actually installed and wired the pump the relay seemed to start working properly. I am getting the engine to turn over and occasionally back fire but not catch. I have indexed the dizzy twice and no dice it still seems like my timing is off.

I am out of time to mess with it. I really wanted to bring this beast with me on my relocation to IL but I start work on monday so I guess I will leave it. No use in trying to tow it behind my Grand Wagoneer if I don't even know if it will run one day...

 

[Thew]

Still no Luck. From what I can tell I have everything wired up. As soon as I actually installed and wired the pump the relay seemed to start working properly. I am getting the engine to turn over and occasionally back fire but not catch. I have indexed the dizzy twice and no dice it still seems like my timing is off.

I am out of time to mess with it. I really wanted to bring this beast with me on my relocation to IL but I start work on monday so I guess I will leave it. No use in trying to tow it behind my Grand Wagoneer if I don't even know if it will run one day...

have you tried feeding a little fuel down the throttle body?
if it tries to start that would tell you its not the timing.
have you put a timing light on it to check to see if the timing is close enough to run? it does not need to run just turn over to get the light to work.

diagnosing the problem is going to be the fun part.
never give up, never surrender

 

[ThisGuyUKnow]

Guys I am proud to report that the cj has officially idled on its own and did not shut down till the key was turned off. This is the first time this little S(#T has done that since I put the ax 15 in it march.

The issue I was having first was that the dizzy was 180 out and was sparking on the exhaust stroke. So as a temporary fix dad just swapped number 6 and 1 plug wires then all the others so that everything would fire on the compression. After that the jeep would start and Idle for a few seconds then kick off. Turned out that since I don't have a down pipe installed for the o2 sensor the system wasn't grounded right. All the sensors are on a grid and apparently if any one of the sensors loses ground the computer will shut down the system. Now it is starting and staying started. It runs rough for a bit then gets smooth as silk. It didn't shut down until the key was turned off but that wasnt very long because the cooling system is not installed yet......

 

[Thew]

Awsome.... drinks for everyone!

More pics please:drool:

 

[ThisGuyUKnow]

Awsome.... drinks for everyone!

More pics please:drool:

Any thing specific you guys would Like pics of???

 

[Thew]

Any thing specific you guys would Like pics of???

I would like to see wiring pics and info on what wiring mods to the 4.0l harness you had to do. it looks like the head swap is straight forward but as everyone should know the devil is in the details

 

[ThisGuyUKnow]

Well its fairly simple. What you want to do is find a good donor first. Then Pull the whole harness under the hood. Take everything. My harness I bought off a part out and so He cut it every place it entered the cab which was two and anything that extended beyond the tranny which would only be the fuel pump controls. THe headlight harness is fairly easy to ID and just unplugs from the harness. dont cut the engine fuse box out. it doesnt really matter if you use a 91 or a 2001 head but with the electrical try to keep everything the same year same model if you can. I am using a CPS from 94 4 banger wrangler so I am one to talk. You basically just take anything that is attached to the engine. Crawl under and un hook the VSS line which should run over the starter over the tranny and plug to the tc or tranny on the drivers side.

Aside from the harness you need to find a part out 91 wrangler. the 91wrangler is the only year jeep that I have found that has a cable driven/electric signal VSS this plugs right up to the Dana 300 and it should come with the plastic adapter for your cj cable.

other than that just remember to grab stuff like dizz and coil etc. If you do this I strongly suggest swapping over the serpentine because its fairly simple and it s fricken cool.

Take lots of pictures before too and just install in the exact same way it was in the donor.We arent really planning on snipping out every useless wire. We are just going to slean everything up back to the main loam. So all the old wires will be there they will just be hidden.

I will try to get my dad to snap pics. I put my ECM on the drivers fire wall like the Stock wranglers but most people seem to put em on the fender.

 

[Sasquach]

What exhaust header and head pipe did you use?

 

[ThisGuyUKnow]

96 97 98 99 Jeep Wrangler Exhaust Manifold 4.0L 4.0 NEW: eBay Motors (item 130394337810 end time May-28-10 03:00:54 PDT)

Thats the one I used. I have an OEM one removed from a 4.0 part out but it was one of those best offer listings and I made an offer and never heard back so I figured he wasnt going to accept so I bought the one in that Link and then the next day he accepted my offer..... DOH.

Any how I need to get rid of the other one so if anyone else wants to do this project I have a header all ready to go!]

I am going to have an exhaust shop make the rest of it and make the bong for the O2 sensor.

 

[Sasquach]

What's your opinion on the location and angle of the head pipe flange? I am concerned it's pointing too much toward the firewall and will require the head pipe to have a very sharp bend to clear.

 

[ThisGuyUKnow]

What's your opinion on the location and angle of the head pipe flange? I am concerned it's pointing too much toward the firewall and will require the head pipe to have a very sharp bend to clear.

Well it is pretty steep I guess. I will have to see what the shop says. There is plenty room between the firewall and thecurrent header so I dont think it will be an issue as far as flow. I am not the first to do this and people commonly use the same year header, so I think it will be fine but like I said we will just have to wait and see what the shop says.

 

[Sasquach]

Well it is pretty steep I guess. I will have to see what the shop says. There is plenty room between the firewall and thecurrent header so I dont think it will be an issue as far as flow. I am not the first to do this and people commonly use the same year header, so I think it will be fine but like I said we will just have to wait and see what the shop says.

Like you say your not the first and should work fine. Some of the other headers on the market look to point there flange straight down and a few not so angled as yours, Just trying to to get it right myself and not sure what way to go.
I have the 7120 head machined and ready to install but will be going with the mopar mpi kit for the simplicity of it, still trying to figure out the exhaust though.

 

[ThisGuyUKnow]

tHat mopar one is freaking expensive

 

[Sasquach]

tHat mopar one is freaking expensive

You are right on that! Took me a while to swallow that pill. I have very poor junk yard access where I live so the route you are on is not a good option for me, that and being in Ca. I like the fact that the mopar unit is carb approved and stickered for the smog nazis making that somewhat pain free. Kinda wish I could do it your way just for the learning exprience if nothing else.

 

[ThisGuyUKnow]

Its been A while since I updated. I am trying to get my dad to take a vid of the cj idling. But without the pipe It will be loud. He finished up the radiator install and wired up the dual contour fan. Starts everytime and I am told purrs like a kitten. If your kitten is a AMC 258 i6 / 4.2l with no down pipe.

 

[ThisGuyUKnow]

New pics. The wiring is complete... Maybe a little more dressing up to make it all hang like it were meant to be in there stock but other than that all the systems are wired up and working. The fan(technically it has its own seperate relay but the power comes from the PDC), charging system, starter, and fuel pump all run through the PDC so I am not running two circuits like in other people's conversions. Everything aside from the sensors for the gauges run through the XJ harness.

Pics

Ideally you would shorten the throttle cable but a ubolt works just as good






For the air intake we are installing this.... 1995 1996 JEEP GRAND CHEROKEE LAREDO 4.0 AIR INTAKE: eBay Motors (item 360286243770 end time Aug-30-10 14:09:47 PDT)
It ended up being cheaper to buy that than to buy a 99+ wrangler intake off a partout.


I plan on posting a video of the truck idling shortly... still have to get a custom exhaust made so it will be loud!

 

[NickCJ7]

New pics. The wiring is complete... Maybe a little more dressing up to make it all hang like it were meant to be in there stock but other than that all the systems are wired up and working. The fan(technically it has its own seperate relay but the power comes from the PDC), charging system, starter, and fuel pump all run through the PDC so I am not running two circuits like in other people's conversions. Everything aside from the sensors for the gauges run through the XJ harness.

Pics

Ideally you would shorten the throttle cable but a ubolt works just as good






For the air intake we are installing this.... 1995 1996 JEEP GRAND CHEROKEE LAREDO 4.0 AIR INTAKE: eBay Motors (item 360286243770 end time Aug-30-10 14:09:47 PDT)
It ended up being cheaper to buy that than to buy a 99+ wrangler intake off a partout.


I plan on posting a video of the truck idling shortly... still have to get a custom exhaust made so it will be loud!

none of your pics are showing up

 

[ThisGuyUKnow]

New pics. The wiring is complete... Maybe a little more dressing up to make it all hang like it were meant to be in there stock but other than that all the systems are wired up and working. The fan(technically it has its own seperate relay but the power comes from the PDC), charging system, starter, and fuel pump all run through the PDC so I am not running two circuits like in other people's conversions. Everything aside from the sensors for the gauges run through the XJ harness.

Pics

Ideally you would shorten the throttle cable but a ubolt works just as good






For the air intake we are installing this.... 1995 1996 JEEP GRAND CHEROKEE LAREDO 4.0 AIR INTAKE: eBay Motors (item 360286243770 end time Aug-30-10 14:09:47 PDT)
It ended up being cheaper to buy that than to buy a 99+ wrangler intake off a partout.


I plan on posting a video of the truck idling shortly... still have to get a custom exhaust made so it will be loud!

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[ThisGuyUKnow]

Reposted