Replacing Ljet with 1.7L Djet on ‘74 1.8L, Ljet in pieces (literally) and have full djet Options

[CSoso]

Hey everyone!

Please don’t roast me if this has been asked before. I spent several hours searching the site… But if it has, a link(s) to any thread(s) would be appreciated…

I have a ‘74 1.8L barn find - sitting 10-ish years due to FI issues. The flapper box is definitely tango uniform and literally in 4+ pieces. Other parts have been removed and am sorting through the rats nest of hoses and pieces. The entire system is in question and I really don’t want to try to find hard to find parts.

The engine was only a quart low and amazingly had very few leaks. The odometer shows 15k miles (115k according to PO). After pulling the engine, I put a ratchet on it (after oiling, etc) and compression “feels” good with no grinding, squealing or grit feel. Will be checking compression officially shortly. The engine’s rebuild history is unknown, so am doing a thorough check. If there’s any hint that it needs rebuilt, it will become a 2056 with microsquirt. If it’s useable as is, I’d like to use parts I have to get her on the road - namely a djet FI system. I would then run her (her name’s Saphira) with the 1.8L until I get a 2056 built. As it’s been said many times here - a 914 going down the road is always faster than one on jack stands!

I have a full ‘73 1.7L djet system and most (missing mps) of a 76 2.0L djet system. I would get a new harness for either djet and rebuild the mps. Assuming I get whichever djet system refurbished, is it a simple remove ljet and replace with djet (distributor too)? Or will the different compression/displacement of the 1.8L cause issues? Any electrical connection issues to the rest of the car? I really appreciate this community and everyone’s helpfulness! Any hints, tips or suggestions are appreciated!

Cheers!

[JeffBowlsby]

Gents,

One of the major concerns with each of the aftermarket FI systems I have seen is the harness which needs to be custom designed and built for each vehicle application, and to accommodate its required parts which are also not commonly repetitive from vehicle to vehicle enough to be cost efficient. The wire terminals are what they need to be to match a component - everything else is pretty much up to be designed and custom fabricated. A customized, servicable, durable harness in our open-to-the-weather engine bays is a challenging thing to acheive, because it needs to:

1. Protect the contained and routed wiring from physical abrasion and thermal extremes. In many locations in the engine bay the harness lays directly on the engine. Factory harnesses do this effectively with heat shrink tubing, which provides a liquid tight assembly at every juncture. No wiring is left exposed unless it is not in a high heat location. A primary failure point of factory engine bay harnesses is the exposed ground wires, or where rubber boots have deteriorated leaving the wires exposed to heat and liquid contamination. What I generically call casing (i.e heat shrink tubing, slit corrugated tubing, PVC, braided sleeving, etc.) needs to be a watertight system once installed and some of the materials available and used for this purpose are not liquidtight.

2. Protect the electrical connections from contamination and provide stress relief at wires-to-component connections. A liquidtight sealed system = from the ECU to the last component. Most if not all the aftermarket solutions do not achieve this. Exposed wires galore. Individual seals on individual wires with some connector designs may help but they often do not provide adequate stress relief and typically leave a portion of the wiring exposed adjacent to the connector housing. Factory style rubber boots are designed to satisfy these two functions.

A part of this problem is the hardware provided on certain components - they are often but not always, computer type electronic parts adapted for the aftermarket FI. DB25-style connections and others, may not be inherently watertight and if so, should only exist in a weather-protected protected environment. That may be as simple as locating the ECU at an interior location (in the cabin for example) or building a separate watertight case if it must be in the engine bay.