Rewiring the 75 EFI harness

[HusseinHolland]

My 280Z has had all kinds of botch repairs to the EFI harness. Quite the mess. I want to get rid of the spaghetti look while I'm at it.

So, I cut the entire harness at the strut tower, and I'll put in a couple gang plugs to tie the new harness to the original. 

These two were the patched thermal timer & ECT - based on the other end where I can see the cable numbers,  I think they had them reversed. That would help explain the horrible starting & rough running

I'm using wiring colors based on Volvo conventions, since that's what I'm familiar with. I'll make a legend to translate from the white numbered harness to the colors used. Using new TE/AMP 282189-1 junior timer housings with waterproof seals for the sensors & injectors. These also have the spring release tabs, so much easier than the old style where you need to get in there with a pick to release them. The gang plugs are Deplhi 16 way and TS hybrid 090/187 8 way

figuring out the layout on the motor before I add the gang plugs & wrap it.

Have to add in the temp gauge wire & the throttle valve, the EGR related wiring I'll dead end since I'm removing the EGR valve & solenoid.

Edited April 2, 2023 by HusseinHolland

[HusseinHolland]

Got the wiring harness tidied up before I trimmed the junction area 

The decel bypass solenoid connector didn't look any better than this EGR one, so I cut that off & replaced it 

Volvo used a somewhat similar connector, with better waterproofing, through the early 90's, so I replaced it with that type

Removed the EGR solenoid, valve, vacuum & exhaust tube while I was there - had to put a helicoil in one stud location

blocked off the exhaust manifold port

Made a blanking plate & added an elbow 10mm quick release for the booster line. I reinstalled the Datsun check valve, I found that the PO's tech had installed it backwards, with the grey side pointing at the intake. No wonder there were notes on the brake booster not feeling right.

 

crimping all the Delphi terminals - 16way for injectors (12) Decel solenoid, Coolant gauge, and ECT

The TPS, CSV, Thermal timer, AAR are in the Sumitomo TS hybrid 090/187 housing on the right

Back together & running. Didn't resolve the cold start issue entirely. I need to add a pressure gauge & see what the pump is doing, and actually function test the CSV/timer circuit

 

Edited April 3, 2023 by HusseinHolland

[HusseinHolland]

Just to add to this - the cold start & warmup cycle is MUCH improved - takes less cranking time & throttle response is better than before. Still need to address the fule pump & feed, as the ppl that worked on it previously loved to run much longer hoses on everything, so there is a crimped loop in the feed to the pump, I would expect that is creating a delivery issue at anything over idle load. In any event, I need to drop the tank to remove the rear bumper shocks, for the skinny bumper install.