D-jet to Haltech 550, Gathering information before I start install Options

[JORACER#40]

Nathan on YouTube Barefoot Garage Jax converted his D-jet to modern EFI using Haltech 550 and hoping Nathan or someone who knows him would message me so I could ask Nathan a few questions.
I am very impressed with Haltech they been very informative and prompt but this is not a common conversion for them.
I am using a variety of sensors manufactures most from The Dub Shop that not standard for Haltech but will work as long I know how to implement each into the tune.
Just trying not to make the same mistakes and be back on the road sooner than later.

This has became necessary due to my D-Jet started failing and trying to get new or remanufactured parts is next to or imposable. (IMG:style_emoticons/default/headbang.gif)

[ClayPerrine]

Replacing the D-Jet injection with any modern, aftermarket injection system will require replacing some hard parts. You will need new injectors, the impedance on the D-Jet injectors is not correct for modern injection. You will also need to replace the circuit board on the throttle body with a TPS. And you won't be able to use the stock harness, you will need to make your own our buy one ready made.

The CHT and the air temp sender will have to be replaced. The stock sensor for a 3.2 Carrera/964/993 works well in a 914 with modern injection and is a bolt in on a 914/4 head.

If you wire it correctly, you can use the stock relays on the relay board for the ECU and fuel pump relays.

The rest is just wiring.

[JamesM]

Replacing the D-Jet injection with any modern, aftermarket injection system will require replacing some hard parts.

What parts you need to replace is entirely dependent on the ECU you use and your creativity/skill.

The first Megasquirt conversion I did on a 914, 20 or so years ago now I replaced nothing but the ECU and did it for less than $200. Even kept the stock d-jet wiring harness. Wouldn't recommend that route to anyone though as you need to be borderline insane to attempt that today with the other available options available now.

This has became necessary due to my D-Jet started failing and trying to get new or remanufactured parts is next to or imposable. (IMG:style_emoticons/default/headbang.gif)

This was actually part of the reason I started working with Megasquirt 20 years ago. Oddly the ability to keep d-jet going today is actually better than it was then but there are SO many other advantages to going with modern EFI its hardly worth mentioning.

I think the most important thing to bring up if you are going to attempt a modern EFI conversion is the learning curve. There is a LOT of information to take in and I have seen a lot of people do things incorrectly or just outright fail due to not having a good understanding of what they are attempting. The hardware/wiring portion of the build is actually the easiest part, make it through that and you have all the software configuration and tuning. Proper tuning being probably the most difficult part and at the same time the most critical given the nature of air cooled engines. Air cooled engines like to nuke themselves with a bad tune. Follow any of the tuning information on youtube based on water-cooled engines and you are at risk of nuking your engine as well.

Im not trying to say don't attempt it if you are not already an expert, the experience alone is an amazing learning experience, just brace yourself for some bumps in the road and a TON of information.

The Holley systems have been getting popular lately as they are a bit more user friendly and maybe more importantly have manufacture support where as with something like Megasuirt its just you and the internet. One of the reasons they are so popular is the onboard autotune feature, which I think can be helpful but also think people rely on it to heavily/put to much faith in it as autotune as how good it is depends on how it is used and the quality of the target data it was setup for.

Haltech has been done but less frequently than Megasquirt or Holley so you may not find ECU specific information as readily however the underlying concepts are the same for any modern EFI build.