TheBeast's 1993 750il Thread

[theBMWbeast]

Okay, I checked, and one is new one is old. More work to do.
Also, I redid my smoke test with the new VCV parts. It is still leaking from the same place. I believe there is wear in the throttlebody itself, as it appears to be leaking from the rod that holds the throttle butterfly on. There are no replaceable parts that I can see for that.

[theBMWbeast]

No pictures, but engine mount replaced. Idle feels like it is 85% to where it should be now.
Might grab the throttles off an 850i in a yard by me tomorrow. Unsure of mileage on that car so might not be any better than the ones on the car.

Also pulled the fpr lines, smelled slightly of fuel. Going to look into it tomorrow. Plus when I did the engine mount, noticed fraying of the main wire to the alternator. Will need to address that, as during running I get high 12- low 13v fluctuating constantly. Idle is much the same.

[theBMWbeast]

Bought the spare EMLs. Tore one apart and broke the wiper arm, but now I understand how it works lol. It still exhibited the same leak through the throttle body though, I would either need a really low mileage unit, or a rebuild to rectify that. If anyone wants to buy a spare EML, pm me.

EML resync didn’t fix anything, so went ahead and ordered some more stuff. Two FPRs enroute, along with an alternator wiring kit. Next on the list will be timing chain tensioner setup, to fix the constant oil leak I have.

I also have a single piston caliper setup from a 91’ 850i. No one has taken it off my hands yet, so considering putting that on the 750, as to my understanding the front brakes are smaller. I’ll give it a little bit longer before I go ahead and do that.

[theBMWbeast]

9DBFAE59-1FA3-40DE-8B04-7ED1E6853C44.jpg

Car started bucking today, so went ahead and installed the FPRs. Idle is 90% where I feel it should be. I’m wondering what the heck it could be. New motor mounts, new fuel system (sans injectors)... I’m guessing the EMl throttle shafts leaking must be pushing it over to give it an ever so slightly rough idle. I’m gonna try some magic to get it to pass smog.

[moroza]

This car surprised me by how it was more than an oversized and optioned-out E34/32. It went to a good home.

I'ven't read this whole thread, so forgive me if this is old news, but in chasing general not-running-quite-right engine issues, the first things to do (besides the not particularly good but very low-hanging fruit of OBD codes, and reading spark plugs) are diagnostics: fuel pressure test and smoke test. The former is a free Autozone rental. The latter is a $70 eBay device (that you could make yourself for perhaps $20) worth its weight in platinum.

EDIT: I see you did a smoke test already, and you've got leaks from what sounds like a throttle bushing? Clever use of O-rings can seal those adequately. Otherwise I'd talk to a machine shop about machining some bronze bushings.

[theBMWbeast]

Yeah thanks for the tips! The E32 truly is more than the sum of it's parts. It's got a solidity to it, that I really quite enjoy.

I actually reached out to a forum member over on the 8 series section, as he rebuilds these EMLs. He said there is a bearing for the throttle shaft that can wear, and as such should be replaced. I even went so far as to buy some spare junkyard units and tear one apart, but couldn't figure how to remove the throttle butterfly from the shaft. So I am stuck on that part as of now. I think everything else with the motor is more or less in order, or at the very least I hope.

[moroza]

Throttle plates are usually screwed to the shaft. Post a pic?

[theBMWbeast]

It is screwed in, I forgot about it for now though.

AE2E7C1B-9026-4E39-89EB-829B29429248.jpg
Replaced the alternator wire, and rerouted it along the fender. Had to do some soldering to fix the oil level sensor, but everything went back in. However I was expecting beautiful mid 13 volts. Instead...
6B9F7604-8C9F-46F9-99C5-D56E70FA2C9E.jpg5C95F107-AB87-46FE-87C5-9B4F078F5217.jpg

Idle, driving, under load. Mid to high 12s, sometimes it drops to low 12s, sometimes low 13s at idle. New voltage regulator, new alternator wire, new battery. I think the last thing left is the alternator itself. I’m going to try and put it off though...

Terrible clunking over little bumps, car needs a suspension refresh. But with the same misfire going on, I want to spend money trying to fix that. Or the massive leak from the timing chain tensioner. Decisions decisions.

[moroza]

Misfire can ruin an engine block. That'd be my priority.

Have you independently verified alternator output voltage, or are you relying entirely on the OBC?

[theBMWbeast]

Misfire can ruin an engine block. That'd be my priority.

Have you independently verified alternator output voltage, or are you relying entirely on the OBC?

OBC only. I’ll crack out the multimeter now that you mention it.

I’ve got my hunches for the misfire. While I have the multimeter out, I’ll check the resistance on the plug wires. Ignition coil too. I’m thinking weak spark in a cylinder or so might be the reason for the misfire, and my high Hydrocarbons for smog. Also eyeballing a fuel injector refresh, but still searching for cost effective Bosch 4 pintles.

[theBMWbeast]

Just preordered these:

https://bimmerbits.in/collections/bl...lenses-bmw-e32

Very excited, and I think E32 owners everywhere will also be excited. It's almost $80 shipped at this price, which I think is worth it. Now to find some stock taillights to try these out on!

[moroza]

Personally, I'm a fan of all-red tails, especially on a black car. Though the extra-correct way to do them is to start with clear lenses, to avoid any trace of orange.
Picture 3682.jpg

Does the M70 use the same injectors as the M30? Junkyard from a Ford Mustang or some other models, ~7 a piece.

[theBMWbeast]

Looks sexy, but I’m a sucker for euro looks

M70 uses smaller 14lb injectors. I have the Bosch mustangs on my m30, love em.

[theBMWbeast]

Busted out the multimeter. What I found was as follows:
Initial startup idle had a 13.78v charging, after running the car around the block for a bit, charging idle was 13.08v

Plug wire resistance in k ohm
1: 6.12 7: 6.20
2: 5.79 8: 5.84
3: 5.64 9: 5.71
4: 5.89 10: 5.69
5: 6.04 11: 5.94
6: 6.23 12: 5.91

If I have my numbers correct, in spec is 6kohm +/- 10%, so that would mean around 5.94kohm would be my max allowable? If so, I know what the next thing on my agenda is.

[a777fan]

10% would be +/- 0.6kOhms. So... 5.4kOhms to 6.6kOms. I think you are a-OK!


Sent from my iPhone using Tapatalk

[moroza]

13.8V is fine. 13.1 on the low side but no cause for concern, expense, or further work.

[theBMWbeast]

10% would be +/- 0.6kOhms. So... 5.4kOhms to 6.6kOms. I think you are a-OK!


Sent from my iPhone using Tapatalk

That is the exact opposite of what I wanted to hear lol. I don’t want to have to keep searching for the problem. But math doesn’t lie (don’t ask me how I messed up 6000 x .01)

[moroza]

Spark plug gap? Fuel pressure? Caps and rotors? Or the throttle plate bushings that failed a smoke test.

[theBMWbeast]

Spark plug gap? Fuel pressure? Caps and rotors? Or the throttle plate bushings that failed a smoke test.

Spark plugs are new and came pre gapped. Fuel pumps are new as of the previous owner. Cap and rotors are new. Throttle plate is obviously still a problem, but I’ve been thinking that I can’t be the only m70 Owner in the world with wear in that bearing, however plenty of higher mileage m70 owners report smoother running than mine...

[moroza]

How about the fuel pressure regulator(s)?

FWIW, I've seen "pre-gapped" spark plugs be way off.

[theBMWbeast]

Both new FPRs (which helped as the car had started to develop a stutter)

I would have checked the gap, but these new spark plugs were dual prong so I didn’t want to messs with it.

[moroza]

Other than defective new parts, I'm out of ideas other than the throttle plate leak. Mileage might not correlate that strongly; those bushings wear with changing throttle angle, not constant. A single trip across town might see more wear than a drive to Sacramento.

[theBMWbeast]

Oh brother....

There is a coolant leak, leaking onto the left side exhaust manifold (it will drip all the way down, to under the car, actually)
I am hoping this is from the heater valves, or one of those hoses in that vicinity. But in the back of my head, with my water pump replacement, I’m fearing the worst...

[shogun]

critical points are usually the expansion tank, the stud at the bottom breaks http://bmwfans.info/parts-catalog/E3...xpansion_tank/
and the aux water pump hose connection stud breaks http://bmwfans.info/parts-catalog/E3...ve_water_hose/
the connection for the hose and/or the bottom of the aux water pump gets cracks where the motor is located at the bottom of the plastic housing.

[theBMWbeast]

I think you might be onto something Shogun. Here are the best photos I could get where I see some leakage

79FAB1EB-B6F2-43D1-87D2-FFD7068E68DA.jpgFC90EEFC-0AFD-41E0-914A-36974F068E15.png

Im thinking it must be either the expansion tank, or the heater hoses/ valves. It leaks down onto the down pipes and runs down to the bottom of the car. I think a leak from the waterpump pipe o rings would probably miss that stuff. I’m going to see if I can get a better view, but I’m planning right now to just replace all those hoses. Maybe even the expansion tank, it is cheap.