[johncampdakota]

I'm installing a 4.3L V6 into a 53' willy's CJ3b and I'm not sure about keeping the EFI or just going with a new manifold and carb. I'm aware that the carb option will be easier but I like the idea of keeping the EFI if I can find information regarding how to do that. The engine I'm using is from a 98' S10 blazer and comes complete with the harness and computer. (I plan to use the original 53' Willys Borg-Warner T-90 manual transmission w/overdrive.)

So here are my questions....

1. I plan to install headers so I assume that there will be an sensor issue there. What do I do with that?
2. No cat converter.... so same question? What do I do with the sensor?
3. Will I need a to reprogram the computer and/or purchase a new "chip"? If so, where should I look for information, parts, and advise on this?
4. I assume there will be a TPS so how do I convert my original mechanical throttle?
5. What have I not considered?

Thanks for anyone who can help answer these questions. This Willy's jeep has been in family since 1969 and I am super excited to get it back on the road again after a frame-off restoration.

 

[curtis73]

If it's coming from a 98, it shouldn't be TBI, it should be port injection. 98 wouldn't use a PROM chip either.

You will have to find someone who can edit the ECM to ignore downstream O2 sensors, and you'll need to find headers that have an O2 bung, or weld in your own if you're keeping the EFI. If the original S10 application was an automatic, you can reflash it for a manual, which just ignores the transmission.

You can reprogram it yourself, but the cost of most editing software is pretty intense to do one job by yourself. More of an investment if you plan to do multiple.

 

[johncampdakota]

If it's coming from a 98, it shouldn't be TBI, it should be port injection. 98 wouldn't use a PROM chip either.

You will have to find someone who can edit the ECM to ignore downstream O2 sensors, and you'll need to find headers that have an O2 bung, or weld in your own if you're keeping the EFI. If the original S10 application was an automatic, you can reflash it for a manual, which just ignores the transmission.

You can reprogram it yourself, but the cost of most editing software is pretty intense to do one job by yourself. More of an investment if you plan to do multiple.

Thanks for all of that great info. Much appreciated. I spent a few hours last night reading about it. Like drinking from a fire hose. So many people are saying it's too complicated and I should just scrap the fuel injection and go with a carb. That just seems short sighted as I plan to keep this jeep and want it to be economical and reliable. The Blazer motor is being delivered with all the wiring next week. Then I will be moving everything over to a reman long block. Any thoughts on the throttle?

 

[curtis73]

If you're talking about going from a rod-style throttle linkage to the EFI, it should be relatively simple. The last one I did (which was an LT1 into a 64 pickup) I just grabbed the throttle pedal and cable from the donor car. It ended up being a little long, but not bad. GM didn't change a lot of things about their throttle cables so you should be able to hit a junkyard and grab some parts.

 

[curtis73]

As far as the EFI is concerned, it's not as bad as you think. GM did all the hard work for you. Hook up the wires to all the appropriate things, plug it into the computer, give it power and ground and you're good to go. Ok, it's not really THAT simple, but almost.

The one thing you'll have to research is gauges. For the most part in 1998, GM's sensors were electronic and they fed both the gauge and the ECM. I don't think it was until the mid-late 2000s that they started feeding dash gauges from the ECM itself. Since you're keeping the BW trans from the Willys, your speedo is taken care of, but if it has a tach, temp gauge, ammeter, etc, that might get tricky. At that point you'll have to decide if you want to keep the Willys gauges and adapt them to the new motor, or get new gauges to match the sensors on the V6.

For instance, the Jeep likely has a mechanical oil pressure gauge. If so, it's just a matter of finding a plumbing adapter to let you attach the tube to the V6. Same would go for coolant temp if it's mechanical. Just leave the sensors there to feed info to the computer, but tap in somewhere else for the Willys gauges.

 

[johncampdakota]

If you're talking about going from a rod-style throttle linkage to the EFI, it should be relatively simple. The last one I did (which was an LT1 into a 64 pickup) I just grabbed the throttle pedal and cable from the donor car. It ended up being a little long, but not bad. GM didn't change a lot of things about their throttle cables so you should be able to hit a junkyard and grab some parts.

Thanks so much. That is very helpful!

 

[johncampdakota]

As far as the EFI is concerned, it's not as bad as you think. GM did all the hard work for you. Hook up the wires to all the appropriate things, plug it into the computer, give it power and ground and you're good to go. Ok, it's not really THAT simple, but almost.

The one thing you'll have to research is gauges. For the most part in 1998, GM's sensors were electronic and they fed both the gauge and the ECM. I don't think it was until the mid-late 2000s that they started feeding dash gauges from the ECM itself. Since you're keeping the BW trans from the Willys, your speedo is taken care of, but if it has a tach, temp gauge, ammeter, etc, that might get tricky. At that point you'll have to decide if you want to keep the Willys gauges and adapt them to the new motor, or get new gauges to match the sensors on the V6.

For instance, the Jeep likely has a mechanical oil pressure gauge. If so, it's just a matter of finding a plumbing adapter to let you attach the tube to the V6. Same would go for coolant temp if it's mechanical. Just leave the sensors there to feed info to the computer, but tap in somewhere else for the Willys gauges.

I had already planned new gauges. I will probably stick with mechanical and adapt. Thank you so much for the help!