Build Thread New CJ owner - TPI L98 - rewiring build

[VTECnical]

Hello all!

I am the proud owner of a '83 CJ7 . Picked her up today. She came with a 3" ProComp lift and a L98 from a '90 Corvette and a Chevy 4 speed.


I am facing a build that will center on the engine. The L98 does not have an ECU or a harness. The chassis harness is a mess too. Here are some pics as of today...



The chassis wiring is in rough shape. Here are a couple of pics that make me want to rewire the chassis harness too...



So, I am thinking of two options. The first is purchasing a new L98 harness from Larry's Electric => http://www.larryselectricsite.com/storefront/viewitem.php?productid=2&groupid=0

This kit includes a new ECU, not the weatherproof Corvette ECU but another Chevy computer that must be installed in the cab of the Jeep.

The other option is a Holley unit => Holley Performance Products HP EFI ECU & Harness Kits 550-601

The Holley unit is programable and also costs about $1,000 more. The only reason to purchase this kit over a near OEM replacement is that the L98 now has a custom short ram intake and MagnaFlow exhaust.

Before I pullout the CC and start buying, I would appreciate all ideas on the route I should take. The Larry's unit is $405 and I hope that would work. Since I am not driving her anytime soon, I might as well rewire the chassis harness too. Please take a look and suggest the best chassis/engine harnesses. Looking forward to getting her on the road. Thanks in advance for your ideas. I'll be reading the Haynes Repair Manual in the mean time.

 

[jasonmark1993]

Id go with the factory ecu and harness. You won't need most of it unless you install all of the emissions stuff. Some of those aftermarket systems are nice, but unless you have some experience with them it can be quite difficult if its not plug and play.

As far as the rest of the harness, are all of the connections/switches in that condition? If its a matter of just replacing just a couple items, Id just do that and reuse what you can. I've never bought an aftermarket harness, I've always repaired the factory one.

 

[VTECnical]

Thanks Jason-

I am going with the renewed TPI harness from Larry's. Just have to save up some money. The Holley solution looks cool but the customer service line told me that my setup should be good with a stock ECU. Also received advice from Bruce, a CJ expert up in NH. Looks like the key to rewiring her will be prep. The total job looks to take 20 hours. Will have an update in the first week of March. Stay tuned!!

 

[jasonmark1993]

cool man; good decision.

 

[Ironmerganser]

The harness from Larrys shoudl work well for the motor. As for your chassis harness, as stated earlier, inspect it and judge. The first thing I did on my CJ was install an new painless harness. Easiest upgrade I did and everything is nice and new now.

 

[VTECnical]

The harness from Larrys shoudl work well for the motor. As for your chassis harness, as stated earlier, inspect it and judge. The first thing I did on my CJ was install an new painless harness. Easiest upgrade I did and everything is nice and new now.

Well, I was able to spend time last weekend in the engine bay and under the dash. I hate to report that the condition of the wiring is horrible.

Random relays, mystery wires leading to nowhere and a host of crumbled connections... I am going with a new chassis harness to play it safe. I would hate to spend time and money on her only to have a major failure due to substandard wiring.

Will purchase a Centech kit for the chassis and hope to start work after this quarter comes to a close. I have found a shop that is nearby to do the installation. While I really want to learn more about the wiring, I feel that money is well spent to have a pro help me out as start with a clean slate.

Thank you for your help. Hope to show you all some pics of my CJ rolling around Rhode Island in July!

 

[sponge]

Please take pics and do a write up! I am sure others will follow in your foot steps again soon.

Good luck I hope to see it running soon.

 

[jasonmark1993]

I didn't look at Larry's price for the harness and ECM but with the advancements with junk yards nowadays you can probably search online/contact them and find a harness. Most of them come with a money back guarantee now also.

 

[VTECnical]

Finally after a long campaign and the close of the 2012 election cycle... I am finally getting a start on my rewire of my CJ.

Just spoke with Jim over at Centech. What a great guy. He is shipping a new chassis harness and I can't wait to get it later this week.

Jeeps: Wiring Harnesses and Kits

 

[sol searcher]

The old TPI ECM is ancient by today's standards and it's electronics are slow. If you plan on modifying the engine you have to burn new PROMs. My experience with the TPI ECM has been miserable for tuning.

Since you need a wiring harness check out EFI Connection's upgrade to a later model GM ECM that can be tuned with EFI Live, HP Tuner,etc. EFI Connection, LLC - Welcome to www.eficonnection.com

Lot' of information on TPIs on the ThirdGen forum
ThirdGen.org

 

[sclose55]

I did a frame of build last year 1974 CJ5 . I put in a1985 l98 out of a corvette with a sm465 Transmission Dana 60 front and rear axles a Dana 300transfer case. I went with a Larry.so electric wiring hardness and ecm it was the best thing I did. If you have any question I have a lot of information also the hardness from Larry's electric let me go from a mass to a map. If you go that way it well work out great for you I just plug it in and it started right up.

 

[ThisGuyUKnow]

Hey OP, isn't that year l98 from a late 80's early 90s vette? if So I just did a TPI harness for my project. I have started making electrical harnesses on the side and I can probably save you some money if you can get an engine harness from a part out vette. It will save you alot of money and I make a good product. PM me if you are interested.

Edit: NVRM i just realized this thread is like 2 years old.