"HoustonRunner" (houstonrunner)
06/30/2019 at 17:22 • Filed to: None
5
7|
"HoustonRunner" (houstonrunner)
06/30/2019 at 17:22 • Filed to: None | 5
| 7 |
I was lucky today to have most of the afternoon for working on the E28. Since I’m still a relatively novice wrench, I set me expectations reasonable - need to resolve the annoying stalling issue.
The issue - when the car get warmed up, and the engine was coming back down to idle, with the AC on, RPM’s would drop to 500 or lower and frequently stall.
So, the M30 engine with Motronic ECU is pretty simple by today’s standards, but still has a number of components that give input on idle. I probably read 50 posts on mye28.com related to idle issues.
What I learned - the M30 just plain doesn’t idle smooth. I also learned how the Idle Control Valve works, what the different sensors on the water pump housing were (since it only happened when warm), what the Throttle Position Sensor controls and how to adjust, and what the throttle plate should look like at idle.
With all of that, what I finally determined the issues to be - the throttle body was dirty.
This shows it when I already sprayed some cleaner on it. You can see it wasn’t super dirty, but per the Bentley (and posts I read), you should be able to see just a sliver of light around the edge of the plate at idle. With the built up gunk you definitely could not see any light.
Once I got it clean I could just barely see light around the edge, so I decided not to adjust it further. It is amazing how much such a small amount of extra air getting by makes.
One thing I will say about wrenching in 2019 is - how did people do it before they had a phone to take pictures of everything as they took it apart. I took almost 20 pictures, and looked back at 4 or 5 to make sure i was getting it back together correctly.
Last comment. The internet is amazing, and you can easily find things from back to the early 2000's. Some of the posts I read from that time really surprised me - the internet and our culture was a really different place. I actually felt uncomfortable reading some of those posts.
Overall the internet is better now. I’m sure there are places on the internet that are still like that, and I’m glad Oppo isn’t one of those places.
MrDakka
> HoustonRunner
06/30/2019 at 17:46 |
|
I’d imagine ol d timey people just used a Polaroid camera
dumpsterfire!
> HoustonRunner
06/30/2019 at 18:00 |
|
Nice work. In between the various grease stained pages of my shop manual are various hand drawn diagrams which might explain the frequent leftover bolt or clip.
TheRealBicycleBuck
> HoustonRunner
06/30/2019 at 18:13 |
|
Cameras? No. The parts were put in labeled ziploc baggies or were meticulously laid out in a prep area. God forbid a cat getting on the bench or a person accidentally knocking over something. The really brave (or really experienced) mechanics would just put the parts in one pan or hubcap or whatever bin was handy.
|
HoustonRunner
> TheRealBicycleBuck
06/30/2019 at 18:20 |
|
I used magnetic parts bowls to help, but still looked at pictures to make sure I had everything buttoned up correctly.
Full of the sound of the Gran Fury, signifying nothing.
> HoustonRunner
06/30/2019 at 18:23 |
|
Get yourself a copy of this book, even if it’s an old version. Tons of useful information on all sorts of systems on every sort of vehicle, with, of course, great detail on Bosch stuff. You won’t regret it.
|
HoustonRunner
> Full of the sound of the Gran Fury, signifying nothing.
06/30/2019 at 19:47 |
|
Will do, any recommendations on version? Look to be a few that I can find used online.
|
Full of the sound of the Gran Fury, signifying nothing.
> HoustonRunner
06/30/2019 at 20:00 |
|
I think I bought the 3rd or 4th edition in the mid-’90s and that helped me to get a better understanding of the various systems in my E21 and E34. Newer versions will of course cover newer technology, so it’s up to you to determine if you want to learn the systems of the same vintage as your car or if you want to be up-to-date on all the latest and greatest automotive tech. It really comes down to your budget. Since I only have two old copies and haven’t made a direct comparison between the two (these things are over 1,000 pages IIRC), I can’t say whether they dropped old tech in n ewer versions or not. I’d say not, because this book gets thicker with every version, and it’s gone from a little book that you could keep in your toolbox to a much larger tome.
My recommendation would be to look at the publishing date and get one copy that’s a little newer than the vintage of your car and then a copy of the newest one you can justify purchasing - I know they can get pricy, like a good Bentley manual. Start with the cheaper, older version first that you can keep in your car or toolbox and then when you’re hooked on it (and you will be if you’re anything like me), go back and purchase a newer edition.