4.3L swap

I have a 1942 Willys Jeep that i built back in 02. It ran w/ the original flathead, it then became turbo charged, then (bf#1 decided) it needed a buick 231, it never got completed- two years later i moved on...(bf#2 decided to play hereo) and picked up a 96 4.3L v6 because he understood the fuel injection stuff-things didnt work out- i have neither bf #1 or bf #2 and a jeep that doesnt run. i figure i built it once i can do it again right?

right! except i'm stuck on the wiring. the motor came out of a 96 2wd s10 blazer- and with the wiring harness for the entire vehicle minus the ECM. I got an ECM and had it programmed to my motor. I have the right transmission adaptor to run my stock tranny nd transfer case (untill i blow it up). The transmission has been rebuilt and recieved a new chevy output shaft. I have the flywheel- 168 tooth, and an 11" borg clutch kit. i am working with the already existing hydraulic clutch linkage and swinging pedals...i think i;m ready to go except i'm confused on how the ECM/wiring works.
I have gone through the wiring harness and eliminated all the unnec. wires (mainly lights). from there i am not sure how to abandon the unnec sensors without confusing the computer. stuff like A/C- jeeps so have A/C thus the point in owning a jeep ...

any advice would be great.
thanks

 

Wow! your not afraid of jumping right into a project! When I did my fuel injection back in 1999 I didn't have the Internet, so I bought a painless wiring harness and replaced my OBD11 computer with a earlier OBD1. That was the way painless had it set up to work back then. I also did not have a factory harness like you do so I had to buy a harness anyway. Now with the information I have now I wish I had the OBD11 computer so I could play with the programing. The older obd1 has a chip instead of a programmable memory.
Do you have a good wiring schematic? That will prove invaluable so you can make a plan on which wires you will want to use and the circuits you will need.
I would start out by drawing yourself a diagram with your needed and wanted components, fuel pump relay, speed sensor, stop light switch, ect., then trace out the wires in the original harness and go from there, it will take some time but have seen it done with very nice results. Good luck and if you get stuck just ask, I'm sure there are lots of guys on here smarter than me! Nice jeep!

 

I'd guess your first, best resource would be the factory service manual for the engine. Is this a TPI or TBI engine? There are lots of books on Amazon about performance tuning of the GM TPI, but I did not see any on TBI. Novak www.novak-adapt.com used to sell a book about dropping Chevy EFI'd engines into Jeeps, but again I looked at the site and could not find a reference to the book. You could call them and ask. Custom EFIs has a book about putting GM EFI into other vehicles, and about tuning to the new app ... good info there, but not very well organized.

There are lots of sites on the net with info about GM TBI & TPI. I'd suggest you put your research hat on, fire up Google and start searching for all the info you need. Your hit rate will be low at first, but if you keep at it, you should be able to find the sources that you need.

Since you are using a 4.3L ECM on a 4.3L, I didn't think you'd need any reprogramming, but apparently you have has a new PROM made. Comments?

hth! and welcome from Boston

 

I have read (I have not looked myself) that autozone online has very easy to read and follow schematics that will allow you to eliminate the stuff you dont need.The painless wiring harness is another way to go.

Scott

 

Look into getting a helms wiring manual they are invaluable.
Helped me out alot.
The only problem I ran into was how to trick the computer into thinking that there was still a evap canister purge valve, if this is not there the computer will have always throw a check engine light.There may be some info on how to get around it now but I dont know.
i wound up sending the harness to Speedscene wiring and have them set it up properly.

 

well I guess I better break out my jeeps wiring harness manual - probly should have started there- didnt even think of it. I have done some research online and have come up with a few things-nothing amazing yet though- Novak has been somewhat helpful-i just discovered them a few weeks back...thanks for the help- i'll keep you posted

 

I agree with the rest...have at least two or three wiring diagram from different sources. I'm currently doing wiring on '88 4.3 TBI (much simpler than yours) and having multiple diagrams gave me some peace of mind regarding what i just hooked up if the information agreed on both sources. If they didn't, then you use the third source...

-painless website has the installation instructions for their kits you can save and print....even if you don't have their kit. one good thing about the painless wiring installation instruction is they give you warnings and cautions
-autozone website
-manuals (haynes, etc)

as suggested, use google. Google is great for researching specific topics down to the wire color...I've been able to enter wire color and computer pin harness number and the word 'chevy' and come out with a couple of bulletin boards where people have talked about that wire and what it does...

good luck...

 

Thanks- i do have the haynes manual and ans slowly but surely starting to understand it. gettign rid off the excess wiring harness (for the rest of the vehicle) has helped a lot...that in its self was flat out overwhelming!

 

Pirate 4x4 has some gurus on this subject as well.

I have done alittle research on this too because,
I have a 4.3 to rebuild and put in on the back burner.

My impression is this isnt to hard really.
Just like any wiring project do one thing at a time and check it off a list.

I think the binder IH board had some good articals on this too.

 

heres a lil update as the whats gotten done...




what do you think of my clearence between the bellhousing and the firewall? is that about enough? I don't realy have any room to move the motor forward or up unless i modify the from cross member, and move the radiator...all in a days work - by myself...

 

it was a flat head 4 cyl...the original motor from 1942 that my dad and i had turbo charged...the block was warped so it kept blowing head gaskets...

the motor was to slow- not realy fun. 55mph max down hill...

 

www.s10forum.com/forum

I've been a member there forever.

A lot of these dudes know the 262 better than the designers: look around, ask anything you need to know. Note also that many of them are jerks; don't get mad about what they say