Wiring harness

[homesea]

I noticed over the last few months that I've been getting intermittent misfires. I tracked it down first time to a dirty injector connector. Cleaned it up and lots of WD40 seemed to stop it, then I started getting it on a different injector, again cleaned up and its been fine.

Two plugs have snapped connectors (the bit the metal clip fits round), interestingly these two are not the two that have caused a misfire and I think are only held onto the injector by good will alone!

I know old 944s suffer from the injector loom breaking down over time and can cause running issues. The last thing I want is an injector to decide not to fire when running full boost!

Anyway I'm after a way forward:

So new loom from Porsche!!
2nd hand loom and hope it lasts a few more years.
After market job like Patrick put in his race car (on other post today).


Is the injector loom a seperate loom from the main engine one?

Cheers,

Tom.

 

[barks944]

I think LR sell loom sections. So you can just make up an injector loom and replace that section of the main harness.

 

[barks944]

You could also just buy a few of these and fit them. [link=http://www.efi-parts.co.uk/index.php?productID=129]http://www.efi-parts.co.uk/index.php?productID=129[/link] You might be able to remove the old pins from the old plastic housing and fit the new plastic housing to the old wiring. Assuming theres no problem with the wires. Best to do a resistance check on the wires if poss.

 

[homesea]

Thanks for the infor Tom. The loom is $129.95 from LR plus P&P and import tax etc etc. So 2nd option looks better, will test the resistance. Looking at the LR website the other end of the loom is the plug in the DME and KLR so it says pins 14 & 15 on the DME and 11, 12 & 13 for the KLR (knock sensor). But in my head I'm thinking 4 pins in the DME, one for each injector other end to zero volts. Or do the injectors fire in pairs?

 

[barks944]

The injectors are wired in pairs, however actually fire all 4 together. There is only one power driver in the ECU, its just connected to two pins on the DME connector. I guess so for other vehicles they could have two separate drivers, just on the 944 they use one. Im close to re-fitting my engine, my connectors are also a bit of a mess. I need to buy a wasted spark pack from EFI-parts for my lux so might order some of those connectors and give it a go. I will test the wiring on my car and see what resistance I get.

 

[homesea]

I think you should stop messing about with Lux and get the turbo DME/KLR working

 

[barks944]

Pretty much done! Just need my turbo back on the road to begin testing and mapping . Cant wait!! Just fitted the hybrid turbo I got from GPF too .

 

[Eldavo]

Nope, I think you need to finish the lux first and then get it out for a public beta test with me

 

[Mike_Pollock]

Would say my 2.7 went on to 3 during the Cotswold Rally last year, diagnosed - by Tony (944Turbo) thank you! - as a broken wire on the No1 injector. So they are getting a bit delicate now. I just cut mine back and used a bit from another loom I had lying around.

 

[VanhireBoys]

ORIGINAL: A9XXC So they are getting a bit delicate now.

That is right Mike.. Wiring looms tend to get brittle over time and the constant movement and heating/cooling will lead to failure... I practically had to rewire a 924 a while ago that had been stood for many years. The loom was so brittle that it was like domestic 1.5mm twin and earth........[] OT but its this actual problem that was a major suspect that caused the loss of a TWA Boeing 747 in 1996.. ! This is why wiring looms are replaced on a regular basis on aircraft. [link=http://en.wikipedia.org/wiki/TWA_Flight_800]http://en.wikipedia.org/wiki/TWA_Flight_800[/link]