2.5 TBI distributor to Duraspark distributor.

[Dickinson County Comanche]

I’ve finally had it with my TBI’s CPS not being perfect on the flex plate and was curious if the 84/85 Duraspark distributors would work on the TBI with little modification. I can get the whole system at the parts yard (dizzy, cap, rotor, and module)

 

I know it’ll need a 12V source and a vacuum line for the advance, but I don’t think that’ll be too hard, just don’t want to waste money if it happens to not work with the EFI.

[Dickinson County Comanche]

I would just pull the whole carb assembly and everything to but I don’t wanna deal with swapping everything over + having to buy a new carb cause the OE ones are $#!&

[eaglescout526]

You’d have to pull everything as the old 2.5L carb also runs from an ECU that communicates with the duraspark. Do you need a new flex plate? I happen to have one. The flex plate could also be rusted to where the CPS can’t pick it up. 

[Eagle]

2 hours ago, eaglescout526 said:

You’d have to pull everything as the old 2.5L carb also runs from an ECU that communicates with the duraspark. Do you need a new flex plate? I happen to have one. The flex plate could also be rusted to where the CPS can’t pick it up. 

 

That (semi) computer-controlled carburetor was absolute garbage. Grab the distributor, for sure. If you want to go with a carburetor, there's are lots of non-computer one- and two-barrel carbs that will work on the 2.5L that are FAR better than the factory thingie.

[eaglescout526]

Yeah it’s not great. My XJ suffers on power because of it. A lot of it is just vac solenoids and a little duraspark box. I only said to grab everything as a just in case type deal but you can do what Eagle said as he knows more than I do. I just know I’m yanking it out in favor of TBI in my XJ haha. 

[89 MJ]

I think you should see if a GM style HEI distributor is available for the 2.5. It is far superior to the Duraspark. My Eagle had a computer controlled carb with a Duraspark distributor and I replaced it with a Motorcraft 2150 and an HEI and it made considerably more power. It’s a bit apples to oranges seeing as I have the 4.2 in the Eagle, but it’s the route I’d go if it’s available. 

[cruiser54]

The CPS can be adjusted to put out more voltage......  http://cruiser54.com/?p=50

[Dickinson County Comanche]

On 11/9/2022 at 5:14 PM, 89 MJ said:

I think you should see if a GM style HEI distributor is available for the 2.5. It is far superior to the Duraspark. My Eagle had a computer controlled carb with a Duraspark distributor and I replaced it with a Motorcraft 2150 and an HEI and it made considerably more power. It’s a bit apples to oranges seeing as I have the 4.2 in the Eagle, but it’s the route I’d go if it’s available. 

After diving through some YJ/CJ-7 Forums, you can convert the 84-85 Duraspark distributors to work on the 4-pin HEI controllers to circumvent the sup-par Duraspark controllers + they’re pretty easy to wire up too.