Damaged Injector/Vacuum Wires

[edwinn]

Sorry for posting so much and I don't mean to FLOOD the group, but have been working away on the Riv for the past month.. getting it in shape for another trip.

It was a GOOD exercise to inspect the HV wires and other components on the motor. Incredibly, the front-center INJECTOR wires turn up badly damaged. (WTF!) The vinyl tape wrap looked burned, even crisp and the conductors were totally exposed!! Not only that, but the copper look like it had a chemical reaction. There were signs of mechanical ripping of the insulation combined with heat or chemical damage.

Wow... shocking!!


Here's a view of the damaged wires. See the vacuum solenoid wires are also ripped.




How could important wires like that be so damaged? I couldn't have happened at the factory (could it?) More likely the guys that did the Plenum/Intake Manifold replacement job.


A closer look at the wires.. both #3 injector wires are damaged. How shoddy!!




I think the proper way to repair these is to pull the harness forward, get inside it and butt-splice (wrap, solder and heat shrink) inside the sheathing. I could do that kind of work, but am not sure how to 'unclip' the injector plug, or how to replace wires going into that plug.


-Ed

[aleekat]

2nd picture. Far right arrow. You'll see a metal clip under your frayed wires. It's a push clip to disconnect the injector plug. I think if you heat shrink the wires going into the plug it would be fine.

[edwinn]

Originally Posted by aleekat

2nd picture. Far right arrow. You'll see a metal clip under your frayed wires. It's a push clip to disconnect the injector plug. I think if you heat shrink the wires going into the plug it would be fine.

Thanks man.. does the clip come straight off perpendicular to the injector? No hinging action there?

The parts and service people diagnosed the cause as "a mouse probably chewed the wires!!" That sounds like a very good explanation, so dismiss the mechanic theory.

Looks like the perfect place for a mouse to 'hang out' below.




Replacement injector plug

I found a NEW injector plug assy at both the Buick dealer and at DelcoLine (for a much better price.) The new plug already has two white wires at lease 12" long and possibly 16" attached. Included in the package are two barrel crimps, but only a soldered butt joint would meet my standards, and best to use heat shrink.

See: http://www.mmxpress.com/technical/connections.htm


The P/N is: 12085491 or PT113




Imagine that.. I'll be getting into the engine harness. Who would've thunk it.


-Ed

[aleekat]

Doesn't pull away and the clip doesn't come off the connector, just push it in towards the body of the connector(injector). Stays attached to keep from dropping it. Sorta spring loaded.

[Tech II]

Yeah that's definitely a mouse problem.......many times they build a nest under the plastic cover......they love that insulation.....

One other place to check is the PCM in the air box.....they build a nest there and eat that harness too.....

As for replacing the harness to the injector, maintain POLARITY......do one wire at a time.......make sure the wire that's connected to the harness goes to the same connector in relation to the new connector.....

Just push in on the center of the clip, and then pull the connector.....

[edwinn]

Originally Posted by Tech II

Yeah that's definitely a mouse problem.......many times they build a nest under the plastic cover......they love that insulation.....

One other place to check is the PCM in the air box.....they build a nest there and eat that harness too.....

As for replacing the harness to the injector, maintain POLARITY......do one wire at a time.......make sure the wire that's connected to the harness goes to the same connector in relation to the new connector.....

Just push in on the center of the clip, and then pull the connector.....

Thanks Tech II,

Making good progress here!!


Injector Plug fitting exercise

Got a hold of an Injector Plug and test-fitted it on Cylinder #5 which was east to access. The WHITE wires on the new plug are 16" long.


Test fit of NEW injector plug. Also see where a Vacuum line runs from the injector rail to the throttle body, identified with YELLOW arrows. I'll need to replace those rubber ELBOWS. The semi-rigid tubing is 0.158" dia.


A few questions

Removing components to repair harness: see the THREE red arrows, from top on down:

1) I can get needle nose pliers behind that connector and squeeze the little tit enough to remove if from the bracket,

2) but is there any reason NOT to de-mate that connector that has a tie-wrap holding the latch closed? or is that for safety?

3) How does one pop-off the vacuum switch.. where there's a thick steel tab holding a plastic tab behind there?

Could get started on the wires but need to proceed with caution. Have a lot of skills but basically...

don't know what the hell I'm doing.


-Ed

[HotZ28]

You have PM

[edwinn]

Finally getting to the Injector Plug replacement

After almost 3 months I finally got around to fixing the CHEWED engine wires. The job probably could be done in 1 to 1-1/2 hours by a Pro, but DIY'ers can futz around and dick with it all afternoon. Lol

It was a fine learning experience, and I'm no longer afraid or intimidated by engine harnesses!!


Crunch!!

This is where I started into the harness.. just downstream from the #3 injector wire where the tubing was crushed due to a cable clamp on vacuum switch bracket.

Edit: it seems now that the sheathing tube was crushed intentionally.. because the cable clamp was too small?




Opening wire bundle

Cutting and peeling the tape with an X-Acto (this can be tedious) the tubing was pulled away from the wire bundle to the left.

Someone apparently yanked it pretty bad here?




Downstream tubing tucked out of the way. About to start upstream.




Opening wire bundle upstream

With upstream tubing opened, the secondary bundles are seen taped-up inside. Interesting!! However this step was skipped when re-assembling. I may rework the general area when doing another ENGINE HARNESS service / update later on (inspecting and replacing old, dried out factory tape) adding these wraps.




Digging deeper upstream, each of the two-wire pairs is taped together, and "harness stops" are wrapped where pairs break out of the bundle.




Foam blocks were used to "stand off" the harness for easier access. This is the HDPE foam (milk jug material?) that was shoved into the front Park Lamps to stop rattling.




Splicing injector wires

Crimps were staggered per the instructions and service manual. A full-scale planning sketch was made to help position the crimps.



However I didn't note where each original tape-wrap was placed. The dozens of photos would provide that.

Below the TWO crimps are installed just like planned!!




Heat shrink tubing used on the exposed Injector Plug leads instead of tape wrap. Black Sharpie pen on one line is the `striped´ wire.




Using a digital heat gun, these barrel splices were NOT heat shrinkable. I applied LOTS of heat, and the wires started to melt!!

This is a mystery.




Wire Prep

The ORANGE vacuum switch wire where the insulation was chewed was CUT in two and a barrel crimp installed, with heat shrink tubing over that. Both injector and vacuum switch wire pairs were wrapped-up with 8 mil, 3/4" 3M vinyl / electrical tape.




Harness Closed

NEW vinyl tape applied to the cable sheath. This had to be partially removed and done over so the branches would be heading off in the right direction. Really a refreshed look on the engine. There is STILL a problem area with very DRY electrical tape (see RED arrows on right.) Plus a sensor wire-pair that goes DOWN the back end of the head is in bad shape. Hell.. now I'll be repairing and re-wrapping harnesses all over the vehicle if the NEW tape holds up after 6 months!

Plus it was easy and fun!!




Job Complete

The harness was then closed-up. Only difference (besides inner wraps) is the vacuum switch pair is now FWD of, and parallel to the main harness due to the stiffness of the splice and heat shrink, i.e. it could not be formed into a curved wire.




Electrical tape

The factory tape was 1.2" wide and 3-4 mils thick however, 3M Heavy Duty electrical tape (0.75" and 1.5" wide) x 8.5 mils thick was ordered from McMaster Carr http://www.mcmaster.com with higher temperature rating. I haven't used the WIDE tape yet, but its' good stuff!!




Deoxit

Here's the stuff I hit every connector with before re-mating. Deoxit D5 is a solution of 5% deox juice and 95% solvent that evaporates quickly. It's not just for electronics and volume controls.. even use it on those pesky intermittent flashlights!!




Problem area

Now I'm seeing a LOT of old and dried-out harness tape, and some broken or damaged sheathing. The plan is to re-work the harness from the back of the engine to the front-right side, replacing tape and sheathing as needed. Plus it will LOOK MARVELOUS!!

Here's a sensor on the forward driver-side corner of the block under the thermostat area. It's subjected to a LOT of heat from the crossover pipe and is cracked, broken and dried out.




Results

Well it started right up and ran as good as ever on a short test drive, holding 2nd gear and revving 3000 RPM. Another successful DIY repair and restoration in the books!!

This summer 2012 project is a WRAP!!


-Ed