Tampa 928s

I chased two shorts on an 86 FI connector so I would do this to see if you have maybe a strand of wire on one of the new connectors shorting together.

Disconnect both computers
Disconnect Ox sensor
Disconnect ICV
This is what I remember with out my notes.

With all the FI connectors removed you should not show a shot between pins.
Move each one around if it shows no short or are shorted to find the bad connector.

I spent a ton of time chasing an intermittent after install my S/C due to bad FI connectors. Mine looked good but when cut open the wire insulation was crumbled when moved it would short.

blown 87

Keep putting either in that motor and you get to build another one.
That is ok though, my second motor was better than my first one was.

fbarnhill

Thanks for the tips guys. Today I am opening the fi harness all the way to ensure the wires are ok al the way through. Blown, that was a one time thing to check for spark and it was used sparingly. I do appreciate the caution though. I tell you what, I feel like blowing the damn thing to hell and back by now. I know the engine is in good shape. The bores were perfect, the pistons were great. The heads were in good shape and thanks to Porken, the timing is set 100% factory. I have made some stupid mistakes like putting the balancer on backwards the first time and setting the timing. But I managed to catch it and get it rignt. So, I will just keep on until I figure it out.

Lorenfb

The easiest approach to determine whether the harness is shorted to ground is to:

1. disconnect the LH ECM
2. jumper 87 to 30 on the fuel injection relay XXV
3. use a test light to check pin 18 of the LH ECM for power

If pin 18 has power, the harness is not shorted to ground.

PorKen

Edited for the OP, LH 2.2

Alan

Here is a thought:

You can't test wether the harness has a short using an ohmmeter when it is connected to ANYTHING.

Disconnect everthing then test between the harness conductors.

If the ECU is connected depending on how you test it may look like a short - you are measuring the ECU output stage - (possibly in reverse bias - quite meaningless for normal operation), With an injector connected - you are measuring the injector coil resistance...

You have to know how to use these tools to get meaningful results.

Alan

Lorenfb

"Edited for the OP, LH 2.2"

And those LH ECMs don't have the inherent failure modes of the later LH ECM.
If fact, they rarely if ever fail, unless someone thru troubleshooting damages them,
as experienced in rebuilding many.

Lorenfb

"You can't test wether the harness has a short using an ohmmeter when it is connected to ANYTHING"

Right, because you are measuring everything connected to the 87 pin (XXV) to ground, not just
the injector, i.e. the feedback thru the injectors to 87 and everything else.

fbarnhill

Thanks guys I was sort of comming to that conclusion. Well I split the FI harness all the way back to the large end on both sides today to the point where I can see all the wires come together. I did find a couple of splits that could have caused a short but I can't swear to it. I pulled all the dampers/pressure regulators also to get to the harness better. The gas that came out was orange. I put a bottle of stabil in it after bringing it into the garage but maybe I was just too late. We will see. I have found a bunch of broken wire covers that need repair. Anyone have any suggestions on the best way to repair a wire that is not cut or broken but is exposed from a broken cover?

I will test the ECU as Ken suggested but it will take a couple of days. Meanwhile, I will have a FI harness that I know will last me another 20 years when finished. I bought this car to do just that. I have driven a shark since 1991 as a DD and I really miss having one. I am in love with my wife's 530 but there is just no replacement for displacement

The good news here is that I used Rogers fi hose repair kit and there wasn't even a hint of a leak anywhere. Not even a sniff.

Benton

Frank, sorry to hear of your troubles. If you end up needing to replace the harness, I have a good one with your name on it.

Landseer

How does reverse of CE panel look?

Mrmerlin

buy the harness Benton has and plug and play, you may also need a new set of computers for the fuel injection.

I put a FI harness in an 86 it took about 5 hours with some assistance,
did it in the parking lot.

Put the key in and hit the start........ Vrooom Bwaaah

Benton

No need to buy Frank, just cover the shipping. I'm up to my neck in finishing up this website by tomorrow afternoon, but shoot me an email and I can probably get it shipped today or tomorrow if you need it.

fbarnhill

Mark, man you are the best. Just let me know the cost. I do need it ASAP. If you have a good set of computers too let me know the cost and I will send PayPal.

Thanks Stank and all the other responders. Stan, I can replace this damn thing with my eyes closed. I have worked on it so long now I feel like I am married to it. MY hands are so bad these days that some days I can only work a few minutes then have to quit. Some days I get whole days. I worked from 2:30 Sat morning until sometime late Sunday working on this issue. I am not an electrical expert but I know how to trace a wire to see if it is connected on both ends.