L-Jetronic Fuel Injection Harness Repair

by Richard Atwell
(c) Copyright 2004-2011

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There are 5 distinct versions of the fuel injection wiring harness used on 74-79 busses with Bosch L-Jet Fuel Injection:

Part number VIN range Features
022 971 761K 214 2 132 408 - 214 2 300 000 1974 CA Automatic
022 971 761P 215 2 000 001 - 216 2 077 583 Electro-vacuum style EGR
022 971 761R 216 2 077 584 - 216 2 300 000 Mechanical style EGR
022 971 761T 217 2 000 001 - 218 2 300 000 CA
217 2 000 001 - 219 2 300 000 Federal
Mechanical EGR, no throttle switches
039 971 761D 219 2 000 001 - 219 2 300 000 CA 79 CA with O2 sensor, no EGR

Chances are very high that you'll never see a 1974 CA Automatic harness because it's so rare.


Repair:

As these harnesses get older they suffer from a few common problems:

New harnesses are not for sale. If they were they might cost $900 like they do for 914's at the Porsche dealership. At present there is no one rebuilding L-Jet harnesses for VWs. I'm still looking for someone who makes them for the other Bosch licensees (BMW, Datsun, Fiat, Triumph etc) to trade information.

All of the parts are readily available except the large ECU connector: I'm still looking for that but given that it's pretty durable and the terminals inside are available, a donor harness will more than do for a rebuild. The Bosch connectors only come in black so you'll loose your color coding unless you repaint the connectors to match.

All you need beside that is some white wire and some similar looking gray heat-shrink. The grounds use slightly larger wiring. The orignal wire contained 24 strands of 0.2mm wire. The closest you'll find is 1.0 mm2 wire (AWG 18) but it doesn't hurt to oversize by a little. The original wiring was labelled with numbers so you'll be able to rewire without too much confusion unless they've rubbed off or your harness is so dirty you can't read it.

Bus Boys sells a tool to remove the terminals from the connectors. There is a tab that keeps the terminal in place when you push it on a male connector. It's actually a very good terminal design but difficult to work with because the parts are so small. Do not try to force the connector out. If there is any resistance then the tab is still engaged and any extra force will cause it to bend over and break when you try to bend it back. Personally, I think a two prong tool would work much better for obvious reasons.

I've thought about replacing the corroded terminals with new ones but it presents a few problems:

Contact cleaners are only so effective. The strong ones are often harmful to plastics which mean you'd have to remove every terminal from it's connector to apply the solvent or sacrifice a spare connector to test to potency of the cleaner. Either way this is less than ideal compared to rebuilding the harness. I estimate the parts cost around $100. Labor would be about 1 day if you have the proper crimper and template laid out on a board as a guide.

If you build one, give me a shout. It's a back-burner project for me at present. This is what a new harness would have looked like:

FI harness

Update 2007:

Recently, I was contacted by rebuilder who has taken on harness rebuilds and does a fabulous job. See Kyle Lacey's website:


References:

History:

05/05/04 - Created
06/17/07 - Added link for Kyle's harness repair business
09/07/11 - Fixed broken photos, added translate button, updated footer