Fuel injection wiring harness question

[climberjohn]

Please assist me with what I hope is not too much of a bonehead question or maneuver.

I, newbie mechanic, just completed that “must do” preventative maintenance task of changing out the fuel lines in the engine compartment. During disassembly I of course disconnected the fuel injection wiring harnesses as one of the first tasks.

Well, like a bonehead, I did not label which harness went to which injector. Now, the squeaky clean injectors are back from WitchHunter (nice work and super fast turnaround, by the way) and everything is apparently put back together right. I reconnected the wiring harness as the last thing, but have no idea if they are in their original position.

When I started the car, it seemed to run really rough. I could be that it was just due to sitting for almost 3 weeks, but I suspect something else.

So, here's the core question: does it matter which wiring harness is connected to which fuel injector? I suspect that it does, as it seems it would affect in which order the cylinders fire. Before I go swapping each side at a time to try to deduce where the culprit is, I also would like to know if putting the wrong harness on an injector will catastrophically screw anything up.

Thanks for any assistance with this. And to those of you who are getting ready to replace those fuel lines, take a moment with a sharpie pen and some masking tape and save yourself some grief.
_________________
'86 Westy, 2.5 Subaru power
Know your limits. Exceed them often.

[Perales]

It doesn't matter, they can be connected to either injector.
_________________
-- 1987 Westfalia automatic (Captain Vino)

[mr_vanagon]

Perales is right. All the injectors fire at the same time so it doesn't matter which connector goes on which injector. Don't be afraid to ask. It's the best way to learn.
_________________
'68 Autostick Bug Mom bought new
'89 Tintop Vanagon Dad bought new

[Dogpilot]

What may have happened is when you plugged the injector plugs back in one or more of the pins may have pushed out. So un-plug them and gaze inside the plug to ensure that all the pins are where they are supposed to be. If one pushed out, you can push it back in place from the rear until it seats then plug it back in.
_________________
Geology with a Syncro rocks!
86 Syncro Westy AKA "The Bughunter"
98 Disco I
08 Range Rover SC
08 VW Rabbit S
1951 O-1G

[climberjohn]

Okay, I'll back off from the self deprecation.

Thanks for the quick replies, but I am bummed it's not a quick and easy fix like a wire swap. The van is definitely running rough, with surging/ between 2K and 3.5K RPM.

Any ideas what might be causing this rough running after a fuel line change? Might the injectors be seated incorrectly, or maybe a bit of dirt have gotten in under an injector?

Thanks!
_________________
'86 Westy, 2.5 Subaru power
Know your limits. Exceed them often.

[Dogpilot]

If it runs rough, then you can pull the plug off each injector, one at a time. When it does not get any rougher, then zero in on that cylinder. You can do the same with ignition wires. Be careful that you are not the ground path when you do the ignition wires, or you may get a little pacemaker action go on with the high voltage.
_________________
Geology with a Syncro rocks!
86 Syncro Westy AKA "The Bughunter"
98 Disco I
08 Range Rover SC
08 VW Rabbit S
1951 O-1G

[tencentlife]

Are you sure you got the little rubber o-ring seals back in place on all four injectors? They can easily fall off when you pull the nozzles out. Or maybe one got cracked as it was put back in. Surging is often a sign of unmetered air being pulled into the system, otherwise known as a vacuum leak. A poor injector electrical connection will show up as rough running, an obvious miss, but not surging.
_________________
Shop for unique Vanagon accessories at the Vanistan shop:
https://intrepidoverland.com/vanistan/

Please don't PM here, I will not reply.

Experience is kryptonite to doctrine.

[kshbaja]

reading this post i feel like i am having some strange sort of out of body experience reading a recent post of mine from another's perspective. i have the same vintage westy, live in the same city, did the same maintenance, had the injectors cleaned at the same place, and ended up with the same issue. i also experienced the disappointment learning that the potentially mismatched injector wire wasn't going to be an easy fix. one thing that was different was that mine was running horribly before hand. i ended up changing almost every sensor and found I certainly had a bad o2 sensor and idle stabilization controller.

you may want to try spraying starter fluid around the injector gaskets and see if there is an air leak down there.

was it running beautifully beforehand? maybe you bumped a connection a little too hard in the process of replacing the lines?
_________________
1986 Westfalia

[climberjohn]

Kshbaja,

That is some kind of cosmic connection! Maybe we can trade tales of woe and wonder at the upcoming PDX Westy roundup some are proposing here.

Thanks to all who chimed in on this (Tencent and Dogpilot, your opinions are especially welcome.) I will go back through my work and see where I may have goofed. She was running smooth before this "repair", so that helps with the troubleshooting a bit.

Peace,
ClimberJohn
_________________
'86 Westy, 2.5 Subaru power
Know your limits. Exceed them often.

[climberjohn]

Okay, I figgered it out. It's polite to post solutions to problems that were happily resolved.

I had another close look at all the components that might have been nudged, elbowed or hip checked during the fuel line replacement.

My eagle eye and razor honed mechanic skills saw after a minute or so it was . . .















DOH!
A single spark plug wire, mysteriously unplugged from the distributor!
No wonder it ran like cr*p.

I feel lame I missed it before, but I'm still glad I asked.
Thanks to all for their help, and she's purring like a kitten now!
_________________
'86 Westy, 2.5 Subaru power
Know your limits. Exceed them often.

[bartt59]

I replaced my FI plug boots during my major overhaul (still in progress) and may have reversed the wires to the plug. Will this cause a problem ?

Thanks,
bartt

[Perales]

Relax, have a beer.They are interchangeable. It doesn't matter. They both fire at the same time so they can be placed on either injector.
_________________
-- 1987 Westfalia automatic (Captain Vino)