Montonic question - help needed PLEASE, 1987 E30 - BMW Forum - BimmerWerkz.com
3-Series (E21, E30) Chat relating to the BMW 3-Series from 1975-1983 and 1984-1991 line. Specific models: BMW 315, BMW 316, BMW 318, BMW 318i, BMW 320/4, BMW 320i, BMW 320/6, BMW 323i, BMW 320i. E30 Family models include: BMW 325e, BMW 325i, BMW 325is, BMW 325ix.

 
LinkBack Thread Tools Display Modes
#1 (permalink) Old 02-29-2012, 09:44 AM
n00b
 
Join Date: Feb 2012
Posts: 2
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
PC_CHENG is on a distinguished road
(Thread Starter)
Montonic question - help needed PLEASE, 1987 E30

Hello All !

Just joined because I found similar threads searching for info - some of you are very sharp and I would appriciate your help big time.

I just bought a 1987 325IS as a project restoration and had it shipped to me . It was running but blew a freeze plug - perfect b/c I can fix easy and got it for great price. I planned on instant rebuild anyway.


It was running when they loaded it on the trailer. The car had blown a freeze plug so they ran it just a min to get on truck. when It reached my home I just pushed it in garage and began the tear-down.


I went to town on it, 2500+ dollars in new everything - after doing a complete timing belt job, tune up, valve adjustment -total freshen up of engine minus pulling head and pistons (next month).....
I tried to start it. I wouldn't start - no fuel pressure. Went through my Bentley book did tests and fuel pumps run with jumper. Voltage is coming to relay -so I changed out the fuel pump relay and main relay. Still did not start - bench tested relays and they click and close circuit fine. but when you stick relay in car socket, with voltage present - no click, no fuel pump.

What I found is that the 12 volt side of fuel pump relay has + power signal to close - BUT the ground brown negative side is not there, ungrounded - no continuity to ground. If you have the relay in place and jump the ground wire to chasis from under the socket - relay and pumps operate. (socket is good)

That leads me to the Montronic ECU - that brown wire ground goes to it. Also the relay next to it (lights)and the main I believe do not have ground connection. (however lights will work)

I followed ground troubleshooting on Montronic with Bentley manual - some of the ground continuity checks came up bad (open). I looked at all the ground connection points on the car - everything looks good - leaving me to ask is it the Montronic unit that is bad ? Does it use those ground wires to signal the various functions ?

Even with the fuel pump running by jumper wire - the car doesn't start leaving me to believe the injectors are not being told to fire either. Some interior functions are not working although fuses are good, like power windows and some lights, little computer read out, etc - some functions work fine and car will turn over all day. (later today I will check for spark but don't think its there)

Another thing funny is with ignition off, I read continuity to ground from several of the fuses in fuse box - all that should be isolated 12+, making me think there is a ground somewhere.

Would the montronic going bad / being fried cause all this confusion ?

There were also indications that the cars battery could have been put in backwards at one point, the large wire from alternator to starter + was burned. I replaced it and closely inspected and repaired any damage to wires touching that burnt one. Would that fry the montronic ?

All fuses are good, changed out, fuse link good, relays all new - and this no ground in montronic wires seems to be keeping car from starting / running.


Help please ???? Any ideas ??

I have this beautiful E30 sitting in garagefreshly tuned with new 17" Beyern mesh wheels, new brake kits, coil-overs, all new grill, fresh painted engine - shes just beautiful and ready to go......but wont start and I'm pounding my head at this point !
Thanks so much for your time - I'm stuck

PS - to make things more confusing, when reading Bentley manual I noticed I had the Montronic 1.1 updated version ECU with (50)? pins - but the plug has less pin connections and wire harness looks like there are possibly professional factory like splices....this model year 325 is right around the date they were swapping to the 1.1 version - did I end up with a hybrid assembled car / wire harness adapted to run on newer Montronic 1.1 ?????? aaagghhhhh

Thanks !!!! Garet
Attached Thumbnails
Click image for larger version

Name:	IMG-20120229-00118.jpg
Views:	90
Size:	545.2 KB
ID:	29980   Click image for larger version

Name:	IMG-20120229-00119.jpg
Views:	110
Size:	351.5 KB
ID:	29981   Click image for larger version

Name:	IMG-20120229-00120.jpg
Views:	152
Size:	401.9 KB
ID:	29982   Click image for larger version

Name:	IMG-20120225-00110.jpg
Views:	94
Size:	697.1 KB
ID:	29983   Click image for larger version

Name:	IMG-20120225-00107.jpg
Views:	84
Size:	668.6 KB
ID:	29984  

PC_CHENG is offline  
Sponsored Links
Advertisement
 
#2 (permalink) Old 03-01-2012, 04:24 AM
42, The meaning of life
 
brettski's Avatar
 
Join Date: Jul 2009
Location: Melbourne, Australia
Posts: 2,405
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
brettski is just really nice brettski is just really nice brettski is just really nice brettski is just really nice brettski is just really nice
Welcome to the Werkz.

Reversing the battery posts could cause all sorts of issues with the electronics, some of the issues could be intermittent.

Jumper the fuel pump and then check the injectors when you crank then engine over with a mechanics stethoscope (listen for the clicking). Check for a spark as well. If the injectors are firing and you have a spark, then you are more than half way way there.


Riding in style
brettski is offline  
#3 (permalink) Old 03-01-2012, 08:48 AM
n00b
 
Join Date: Feb 2012
Posts: 2
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
PC_CHENG is on a distinguished road
(Thread Starter)
Hello Brettski - and thanks for the welcome and reply...I was hoping to hear from you I read some good help on other threads from you and the guys.

So I put a noid light on #1 injector plug this AM before work to make sure -

When I connected the neg battery cable the car starter took off on me - out of control car starter....
It did that a couple times when I was testing the Montronic a couple days ago as well.

When I was testing the car before as I mentioned, I had the fuel pump jumped and running, and tried to start the car - it just cranked over and nothing - so I am quite sure there were no sparks.

Good news is I have a montronic ECU reman showing up today from Pelican parts, next day air.
So - I will slap that in and see if thats the issue.

Whith all that chaos going on - does it sound like the ECU to you ? I think so...

Any warnings about anything before I puit the new ECU in ? ( I know about static handling etc) I am worried about some possible short because of this run away start issue now. Hopefully its just a scrambled ECU thats causing all the weird stuff.

Thanks so much for your help and advice !!

Garet
PC_CHENG is offline  
#4 (permalink) Old 03-03-2012, 09:05 AM
Captain... Savvy ?
 
Jack Dabsy's Avatar
 
Join Date: Apr 2011
Location: Barnsley UK
Posts: 2,194
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Jack Dabsy will become famous soon enough
Garage
I would suspect ECU (ECM) is the fault... Or at least the signals it employs !
Change of polarity can have disasterous effects to critical components such as the engine management.
Find a working ECM and swap over to test, just to ease our suspicions !!


Eso es todo!
Please press the "REP" button if you are happy with your response/answer...

Please JOIN, or just have a look... Its Totally FREE...
BMW Part Market

BMW Online Manuals (TIS)

New Member ?
Jack Dabsy is offline  
Sponsored Links
Advertisement
 
Reply

  BMW Forum - BimmerWerkz.com > BMW Model Specific Forums > 3-Series (E21, E30)


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
User Tag List

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Similar Threads
Thread Thread Starter Forum Replies Last Post
Assistance Needed - Restoration Question Coach K M-Series (M1, M3, M5, M6) 1 04-26-2010 04:02 PM
1987 bmw e30 (316 m10 ) tonymiser 3-Series (E21, E30) 12 04-22-2009 08:38 PM
new here with a question on a 1987 635csi fiberglasslvr 1,6,7,8 - Series and Mini Cooper 0 02-13-2009 03:34 PM
1987 325 decisive_guy 3-Series (E36) 3 03-08-2005 08:25 PM
1987 325 FloridaHawk82 3-Series (E21, E30) 1 05-19-2004 10:36 AM

Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome