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Hi
I have a 1978 928 that has been fitted with a 1984 S engine with LH Jetronic.
The problem is, that the after the engine was installed, the project stranded and the engine did no run for about 10 years now.
Can someone please help, so I can get this engine running again? The problem is the new LH Jetronic. How do I connect this right. I can’t be the first who have made this conversion?
Thanks
Peter
No, I dont have the K jet and I want to keep the LH Jet system. I have the ECU for it. The problem is, that the electrics dont fit in the old fusebox. I also have the fusebox from the LH Jetronic
Yes that is a problem....so many changes in the various wiring harnesses. And no I do not recall anyone ever doing that swap...Why anyone thought it was possible or easy is a mystery to me.
How do you know the engine ever ran with this arrangement? If it was running and just parked you are in a much better place than if they never got the conversion completed.
How do you connect the LH? Is this car using only the LH or did they convert to the EZF ignition system as well? It's easy to tell if they converted the ignition, this setup would have a twin distributor and two coils. The stock ignition system will be a single distributor / coil and have an ignition brain box on the inside of the fender, drivers right, just below the jump start post.
Assuming they followed the stock routing, there should be a large plug in the passenger foot-well where the LH computer will connect to the harness (EZF too if they converted the ignition).
Originally Posted by James Bailey
And no I do not recall anyone ever doing that swap...Why anyone thought it was possible or easy is a mystery to me.
I converted my 81 L-Jet to LH/EZF from a EuroS. Really not much different than converting a CIS car to the same system (which I am in the planning stages of doing with my 79).
The car never ran with this setup! The wiring was never connected.
The ignition system was also converted, but also never connected. I do have the ignition box to go with it to.
No way to sugar coat this, you have a real mess on your hands.
Even if you have the LH/EZF harness, the ignition controllers need to be wired in and that harness is part of the front chassis wiring. Anyone doing this conversion would most likely make their own wire since swapping a chassis harness adds a lot of work. The wires for the ignition brains going to the EZF is a special shielded cable. If the proper cable isn't used, the ignition system will be susceptible to noise and all kinds of running gremlins.
Here are some photos of how I mounted the ignition brains and coils:
I am very happy that I found you Hacker-Pschorr!
I am not sure if I have the ignition brains on you pictures, but I will get them! I have a box like the box for the ignition…or is there two boxes for the ignition?
Could you give me the part numbers? I will then track them down!
I am also quit sure that I only have one ignition coil but the two distributors. I will also have to updated there.
Where are you located? Some of these parts can be found used and Mark Anderson @ 928 International will be the best source. He also supplies any new parts these cars need.
For only new parts look up Roger @ 928's R Us in Texas. Both shops regularly ship around the world. Just call / email them with what you need, they'll know how to find it.
Rough check list:
1. Fuel Brain - LH
2. Ignition Brain - EZF (you'll see EZK referenced in threads, those are in 87+ cars)
3. The two ignition controllers from my photos. Made by Bosch, very common
4. Two coils - need the units from a EuroS, 85/86 or anything newer. I think I have S4/87+ coils in my car
Since they transplanted in a EuroS engine the crank sensor should be in the back of the engine in the bellhousing. I had to add one since I used the original 81 engine. Make sure that is there, if not (and there isn't a hole) that's a huge problem.
As you can see in my photos, I had to move the power steering resivior forward to make room for the two coils. I spliced in a piece of hose for the return line (two hose clamps). I'll run a new complete hose someday.
It could really help if you post up photos of everything you have.
If you drop me an email to the links on my website I can send you copies of the Test Plan for the 84-86 Euro LH 16v. It gives circuit diagrams and also how to check out that all is well.
I am located in Denmark, so I will find the parts here in Europe.
1 and 2. Fuel and ignition brain looks very much the same? I should have both.
3 Do you have the parts number on the ignition controllers?
4 Should not be a problem finding two coils.
Crank sensor must be fitted, cause the entire engine was swapped.
Another big problem is attaching the connectors from the engine to the big fuse box/harness. I guess this is quit hairy project? All the other connections of the car are plug_and_play, but the connectors from the new engine are completely different.
I will take some pictures next week.
Should I post it here, or write you directly? I guess here is better, I cant be the last person with this issues.
I think the lowest risk solution would be swapping the whole harness and using all LH fuel and ignition parts.
If you're mixing and matching and fabricating, you might consider instead going with something like Megasquirt and setting up your own speed-density or MAF based control system. This would involve a lot of fabrication (wiring, mounting for sensors, etc), but would allow total flexibility, and would put you into an area with a decent amount of support, rather than being one of only a couple of people to ever do this (although, I have to say that our 928 community is exceptional in the knowledge and support we have here). It would also allow you to do really interesting modern things, if you want, like sequential fuel injection and distributorless ignition.
The two ECUs, LH (fuel) and EZ-F (ignition) look different. They should be located at the side of the passengers foot well, behind a piece of vertical carpet.
The LH is the larger shiny box with a number like 928 618 123 00 or 02.
The EZ-F is the small grey box with a vacuum pipe union on it, part number 928 618 124 00
03-10-2017, 06:34 PM
K-Jetronic to LH Jetronic conversion
