Progress

#1

This weekend I finished the wiring repairs. Several shorts were repaired and a good bit of wire with heat damaged insulation was replaced. In the process I had to go into most of body harnesses to find and fix damage. What fun! Seems like a PO had added an audio system and perhaps an alarm or maybe remote entry. In the process some tactical errors were made. Some of the “fixes” jumpered power around the damage, which also had to be fixed.

Everything that I need to have work now does, but there was a bit of excitement at the finish. I had just finished neatening up the harnesses under the dash and realized that I had not ever checked to see if the HVAC blower worked. It didn’t and the cause was obvious. The starter I used doesn’t have the unloader switch, so the unloader relays weren’t pulling in. That is easy, just ground the unloader control wire.

Switch on and yes the blower works. One final check of everything looks good. Switch off and everything stays on. WTF? Pull the ground off the unloader relays and everything switches off. Switch on then switch off and everything behaves. Enable the unloader relays and I can’t turn off the car. At least it is a repeatable fault.

After some meditation with the wiring diagrams I realize that K7 just controls the windows and sunroof, which are no longer there, so it gets removed. No change. That means that one of the circuits controlled by K5 has to be cross connected back to switched ignition and is causing the relay to latch. One circuit is part of the the aux fan (not present), interior lights, and mirrors, the other is part of the aux fan and HVAC. But the mirrors were working with the unloader disabled, which makes that circuit the prime suspect. Sure enough a close look found a splice that shouldn’t be there that I had missed. Problem solved. The PO got away with that botch before only because fuse 19 was blown.

Now to put the dash back in, input the calibration data for the oil pressure, water temp, and fuel sensors into the IQ3, prime the engine with oil and fire it up. With any luck at all I’ll be making noise tomorrow.

#2

Well, yeah. Of course that’s where the problem was!! You should have just asked. We could have told you that. :S :blink: :laugh:

Please post a sound/video clip of that bad boy firing up so we can all cheer your hard work.

#3

Tracing shorts on a messed up harness is number one on the list of things that makes you want to pull all your hair out with your bare hands.

I saw a really nice current tracer for automotive application but I can’t seem to find the link to the product.

Good to hear the car is coming along.

#4

The neatest wire tracer I’ve ever seen had one part that you connected to the conductor of the wire of interest. The other (sensor) part could ID the wire by just touching the probe to wire, on the insulation or conductor. I could have used one while I was fixing this mess.

#5

Great Jim glad everything is coming together.

#6

So you’d support a new rule that allowed us to replace the wiring harness with a painless system?

#7

Jim, glad it is coming together for you.

#8

IndyJim wrote:

There were times during this struggle that a rule change to steam power sounded like a good idea.

Until one has seriously dug into the wiring, one doesn’t fully appreciate its complexity.

#9

Jim, I’ll take your word for it. I thought about asking Scott if he agreed but decided against it.

#10

What is always fun on the BMW harness is that the engineers were quite fond of bundling several hots or grounds within the harness. And, guess what…they will come loose and cause untold problems. If you wade into the harness, these points are the first that should be address with crimp/solder connections. That cures a misterous cut out problem I had at the 2008 ARRC that cost me positions:angry: CB

#11

Yeah they use an interesting splice. Apparently they have a way of partially fusing wires together to make the splice as there’s no solder or crimp sleeves involved. If it works, fine, but I’ve seen poor connections result from those splices. And since they bury those splices all through the harnesses it can be a lot of fun chasing down an intermittently poor connection.

#12

My fuel tank mod to prevent starvation when the tank is low. I added a transfer pump to the left side that drops fuel into the pickup bowl for the high pressure pump. That and the siphon should get the job done.

#13

You are a wildman.

#14

I like that idea.

#15

Might be nice to get a rules allowance for stuff like that as I believe there is none currently.

#16

jlucas wrote:

[quote]Might be nice to get a rules allowance for stuff like that as I believe there is none currently.[/quote]9.3.1.3.2 Any commercially available fuel pumps, hoses, and fuel
tank baffles are allowed. All other fuel system components must remain
stock.

I believe the above covers it. This was added last year specifically to allow folks to engineer better fuel delivery solutions for chronic starvation.

#17

9.3.1.3.2 is partly what prompted the modification as it makes the mod legal in my opinion. It’s nice to see that Chuck agrees.

#18

yes, and it is why we went back to the stock FPR - do almost anything you want to improve fuel delivery, but the FPR will limit the pressure to the injectors.
bruce

#19

Fired up the new engine tonight for the first time. The valves are a little clackity, but that is fine for the moment. I’m reasonably sure an adjustment after a bit of run in will quiet them down. Oil pressure looks good and the engine sounds healthy.

I have a seeping leak on the top of the fuel tank on in the vicinity of the high pressure pump. I didn’t notice it until fuel dripped off the bottom of the tank. So I can’t tell right now where it is coming from. Once it dries off I can find and fix the leak. Then I can take it out for short spin, albeit a cold short spin.

#20

Great news! Look forward to seeing you back racing at CMP.