Search found 174 matches

by Robert Bondi
Sat Feb 22, 2020 7:22 pm
Forum: Tech Forum
Topic: 1976 530i ECU internal circuit boards view
Replies: 5
Views: 41

Re: 1976 530i ECU internal circuit boards view

Hey Mike,
Great pics. Good to see the FAQs are still getting used so many years later. Scott Stewart pioneered the conversion; I added the visuals after doing the project myself. Yeah, the E12 ECU is a basically a simple analog computer in a very large box by today's standards.
by Robert Bondi
Wed Feb 19, 2020 12:33 am
Forum: Tech Forum
Topic: ballast resistor with conventional ignition
Replies: 7
Views: 111

Re: ballast resistor with conventional ignition

Awesome schematic, Mike! I particularly like seeing the inside of the coil which both explains 3 terminals, rather than 4 for a basic transformer, with the common node inside and the common node also creates asymmetry and explains a polarity difference for the low voltage terminals with respect to t...
by Robert Bondi
Tue Feb 18, 2020 4:23 am
Forum: Tech Forum
Topic: ballast resistor with conventional ignition
Replies: 7
Views: 111

Re: ballast resistor with conventional ignition

Mike, Thanks for bouncing some ideas. It's definitely a 12V system, but I agree that the polarity issue is probably the most likely cause of my melted wires. In ordering that new 12V coil, I had checked that the Euro 528 coil and U.S. 530i coil are the same part number and I further confirmed that w...
by Robert Bondi
Mon Feb 17, 2020 4:15 am
Forum: Tech Forum
Topic: ballast resistor with conventional ignition
Replies: 7
Views: 111

Re: ballast resistor with conventional ignition

Another detail. Old coil had blk/red wire on the negative terminal and that was a running arrangement. I kept blk/red on the negative terminal on the new coil. All the manual references I have show blk/red on the positive terminal. Perhaps reversed polarity was worse than the attempt without ballast...
by Robert Bondi
Sun Feb 16, 2020 3:00 pm
Forum: Tech Forum
Topic: ballast resistor with conventional ignition
Replies: 7
Views: 111

ballast resistor with conventional ignition

Slow going on the Euro 528 project car...Been doing regular drives and dealing with a little bit of Solex 4A1 carb variable behavior. Latest issue is unreliable starting and troubleshooting has isolated it back to the high voltage terminal of the coil and no spark. I'm clearly dealing with some non-...
by Robert Bondi
Tue Dec 24, 2019 1:54 pm
Forum: Tech Forum
Topic: Proper coolant (or newer types that protect iron blocks)???
Replies: 9
Views: 337

Re: Proper coolant (or newer types that protect iron blocks)???

I've been running the Prestone long-life orange formula since around 1999. It's also an OAT or HOAT forumulation. I've been very happy with it and basically run it in all my vehicles. Engine was rebuilt in that span too and everything looked pretty good on the inside. Since it's free of silicates, y...
by Robert Bondi
Sun Jul 07, 2019 7:12 pm
Forum: Tech Forum
Topic: Where's the best place to buy.....
Replies: 2
Views: 415

Re: Where's the best place to buy.....

I used to frequent BMP, then BavAuto for common maintenance stuff. They're now both extinct. I agree with Mike on Autohaus AZ and RockAuto for common stuff. You might also check Pelican Parts (well liked by E28 guys I know) and ECS Tuning. ECS sort of paired up with BavAuto as BavAuto closed and wer...
by Robert Bondi
Sun Jul 07, 2019 7:02 pm
Forum: Tech Forum
Topic: Swapping combo relay from a 76 530i to a 77 530i ?
Replies: 5
Views: 571

Re: Swapping combo relay from a 76 530i to a 77 530i ?

I think it would work, but that's a guess. I suspect the black plastic case is more an indicator of much more recent manufacturing than a different part and possibly also a part number supercede to explain that difference too. I can tell you my 77 530i originally had a metal case combo relay too. It...
by Robert Bondi
Sun Jul 07, 2019 6:46 pm
Forum: Tech Forum
Topic: No click or fuel pump hum when AFM flap is opened?
Replies: 6
Views: 670

Re: No click or fuel pump hum when AFM flap is opened?

I also like to jump pins 36 and 39 on the AFM. That bypasses the AFM flap fuel cutoff and you can
test fuel pump operation without starting car. Pump will run with ignition in "ON" position before cranking. Combo relay is certainly a common culprit for your problem, as discussed.
by Robert Bondi
Sat Nov 10, 2018 1:22 pm
Forum: Tech Forum
Topic: Strange Stall/ No Start - Overheated coil?
Replies: 17
Views: 1709

Re: Strange Stall/ No Start - Overheated coil?

Hey, Tom. Yeah, that's the ICU box. It should have transistors inside - that and the ECU is about
as sophisticated as electronics were in the late 70s. I can take a look in my factory manual this weekend. I've also got a Haynes manual I need to fish out.
by Robert Bondi
Wed Nov 07, 2018 8:50 pm
Forum: Tech Forum
Topic: Strange Stall/ No Start - Overheated coil?
Replies: 17
Views: 1709

Re: Strange Stall/ No Start - Overheated coil?

I was about to suggest the ignition control unit (ICU) for the transistorized ignition as Mike W is describing. Having seen your car, I know you've got the old school distributor. Next question is whether your distributor has the inductive pickups or the points/condensor. If you have the inductive p...
by Robert Bondi
Sun Oct 07, 2018 12:34 am
Forum: Tech Forum
Topic: E28 drive shaft compatibility
Replies: 8
Views: 786

Re: E28 drive shaft compatibility

When I put the Getrag 260/6 I found that the e28 driveshafts had a different profile to the e12, basically the e12 gets narrower before the center bearing where the e28 does not. So the e28 driveshaft might hit that area. You can kind of see it in my picture below, if the driveshaft keeps going for...
by Robert Bondi
Sun Sep 30, 2018 12:14 pm
Forum: Tech Forum
Topic: E28 drive shaft compatibility
Replies: 8
Views: 786

Re: E28 drive shaft compatibility

Thanks for the responses. I am aware there are a lot of parts that look identical, yet have different part numbers. There are a bunch of parts for the 528i that are the same, but lighter/thinner, than the 530i. Given how rare all these parts are getting, I'll just error on the side of grabbing the E...
by Robert Bondi
Tue Sep 18, 2018 11:40 pm
Forum: Tech Forum
Topic: E28 drive shaft compatibility
Replies: 8
Views: 786

Re: E28 drive shaft compatibility

An 85 e28 and a 80/81 e12 have different part numbers so likely not a direct fit. Driveshafts can be professionally shortened though. I would think there are plenty of used ones out there. You’ll need the correct bell housing for the analog speedo drive if you don’t already have it. Yeah, my though...
by Robert Bondi
Fri Sep 14, 2018 7:50 pm
Forum: Tech Forum
Topic: E28 drive shaft compatibility
Replies: 8
Views: 786

E28 drive shaft compatibility

If one obtains the Getrag 265/6 5-speed from an 85 535i, is that drive shaft compatible in the E12? I did some homework in the FAQs. Realoem seems to suggest the E24 of all years is a safer bet on the 5-speed driveshaft. The knowledge from owners of multiple BMWs is invaluable on interchange questio...