1991 325i erratic tach,economy,speedo inop. - BMW Forum - BimmerWerkz.com
BMW Forum BMW Forum

Auto Insurance

» Featured Product
Wheel & Tire Center

Go Back   BMW Forum - BimmerWerkz.com > BMW Model Specific Forums > 3-Series (E21, E30)
Register Home Forum Active Topics Gallery / Showroom Auto Loans Garage Search Today's Posts Mark Forums Read Auto EscrowInsurance

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.

BimmerWerkz.com is the premier BMW Forum on the internet. Registered Users do not see the above ads.
Reply
 
LinkBack Thread Tools Display Modes
Old 12-26-2005, 11:14 AM   #1 (permalink)
n00b
 
Join Date: Dec 2005
Car:
Posts: 10
Photos:
djborya is on a distinguished road
Red face 1991 325i erratic tach,economy,speedo inop.

i just bought this car i am more of MB guy then bmw, so maby one of you have had a same problem.engine speed tach(RPM) reads about 1000 rpm below what it should... so if u let the engine idle gauge reads-0 give it gas,up it goes....now the economy gage just jumps all around at any given time especially when u apply accelerator..ok and for the speedometor it's completly dead does not move at all....I am a sertified auto tech of about 12 years, mainly mercedez,audi and vw.....any help is greatly appreciated...
djborya is offline   Reply With Quote
Sponsored Links
Advertisement
 
Old 12-26-2005, 08:28 PM   #2 (permalink)
Teh Peetsa Gai
 
ldsbeaker's Avatar
 
Join Date: Apr 2004
Location: Havelock, NC
Car: '86 325es, '87 535is
Posts: 3,478
Photos:
ldsbeaker has a reputation beyond reputeldsbeaker has a reputation beyond reputeldsbeaker has a reputation beyond reputeldsbeaker has a reputation beyond reputeldsbeaker has a reputation beyond reputeldsbeaker has a reputation beyond reputeldsbeaker has a reputation beyond reputeldsbeaker has a reputation beyond reputeldsbeaker has a reputation beyond reputeldsbeaker has a reputation beyond reputeldsbeaker has a reputation beyond repute
It's probably your SI board. It runs all the crap in your cluster. Maybe your batteries died, exploded acid all over, and then ate the shit out of your SI board. You're looking at about $100 to get a new board, I think.
__________________
'86 325es (TURTL3): PJ peetsa hawler
'87 535is (BADWATER): almost done... really.
'86 325e (GRN HLL): DD/show/rocket
'04 x3 3.0i: Wife's Bimmer (manual, woot!)
My BMW Blog
ldsbeaker is offline   Reply With Quote
Old 12-26-2005, 08:52 PM   #3 (permalink)
n00b
 
Join Date: Dec 2005
Car:
Posts: 10
Photos:
djborya is on a distinguished road
umm well here's the update i pulled the cluster out, pulled the 2 boards out of the cluster and visually inspected them both..the board witch has the istruments plugged to it is the one of my consern... i found several resistors to be loose on the board... so i re-saudered everything that was in question, as for the other board,it looks good (to a naked eye) but i did put a volt-meter on the batteries that are on the smaller boars i guess that's the "si" board as u call it... i desided to do away wit this on-board battery madness onse and for all (and by the way they are not re-chargable as many people say it said right on the battery "do-not re-charge!")So i went to a radio shack and bought a 4-AA battery holder or whatever u call it 1.5 v X 4 is 6 volts,the batteries that came out totalled 6 volts (3 each) ,came home wired it up,and ran out of steam, ill be putting it back in the car tomorrow , will update then...
Boris S.
1987 MB 420sel (unmolested)
1987 VW Cabrio 16v conversion Turbo
1985 MB 300d vegetable oil Fuel conversion
1991 325i (w/prblems)

Last edited by djborya; 12-26-2005 at 08:59 PM.
djborya is offline   Reply With Quote
Old 12-27-2005, 05:38 AM   #4 (permalink)
Neutral Member
 
luckycat's Avatar
 
Join Date: Dec 2004
Car:
Posts: 50
Photos:
luckycat is an unknown quantity at this point
Red face

HI.
Sounds like that your not the first to repair the board. Not sure what year your car is but I know that 325's from 85 to 90 absolutly have rechargable batteries. Some are AA size ni-cads, and some are shorter 3.3 volts ni-cads.
In either case, you should replace them with Lithium rechargables which have a much longer life. The fact that you found loose conponents is scary, and you might have to change the SI board.
You can find a schematic of the cluster at the link below.

http://www.bright.net/~jimshaffer/9.pdf

Good luck!!!

jim
__________________

Last edited by luckycat; 12-27-2005 at 05:42 AM.
luckycat is offline   Reply With Quote
Old 12-27-2005, 06:02 AM   #5 (permalink)
n00b
 
Join Date: Dec 2005
Car:
Posts: 10
Photos:
djborya is on a distinguished road
Question batteries

I donno if they are re-chargeble or not,but they are the smaller ones and it is clearly printed on each battery - DO-NOT RECHARGE (i donno what that means)used: Oh,and they are ni-cad(also written on the battery)
Boris S.
1987 MB 420sel (unmolested)
1987 VW Cabrio 16v conversion Turbo
1985 MB 300d vegetable oil Fuel conversion
1991 325i (w/prblems)

Last edited by djborya; 12-27-2005 at 06:11 AM.
djborya is offline   Reply With Quote
Old 12-27-2005, 10:47 AM   #6 (permalink)
Neutral Member
 
luckycat's Avatar
 
Join Date: Dec 2004
Car:
Posts: 50
Photos:
luckycat is an unknown quantity at this point
Red face HuH?

That clearly makes no sense...

All Ni-cads are rechargeable. The reason they are present in the SI board is to insure constant voltage to the board in the event of a dead or disconnected main battey. Otherwise you would lose the service/oil change count.

Are you sure that it didn't say "Do Not recycle"?

Jim
__________________
luckycat is offline   Reply With Quote
Old 12-27-2005, 08:12 PM   #7 (permalink)
n00b
 
Join Date: Dec 2005
Car:
Posts: 10
Photos:
djborya is on a distinguished road
batteries

I donno, let me get my reading glasses and check it again,any how enough sorcasm,i put the cluster back in the car, guess what ? the same gages do not work.. also somehow now, the tach does not move at all seems like i did more damage then repairs....well tomorrow is the ultimate test, figured out witch pins on the speedo are hooked to what(12v power,ground,signal) so i will eliminate the cluster all together and wire up the speedo directly to power,ground,and signal wire..from speed sensor (hoping for better luck then..)If it works i will hard wire it that way(by-passing the whole cluster all together) Thank god my brain still works!(can't say the same about this fine piese of german engeneering)
Boris S.
1987 MB 420sel (unmolested)
1987 VW Cabrio 16v conversion Turbo
1985 MB 300d vegetable oil Fuel conversion
1991 325i (w/prblems)
djborya is offline   Reply With Quote
Old 12-28-2005, 08:31 AM   #8 (permalink)
Neutral Member
 
luckycat's Avatar
 
Join Date: Dec 2004
Car:
Posts: 50
Photos:
luckycat is an unknown quantity at this point
Hi,
No sarcasm intended! A problem is a problem right? We just need to figure it out, then the next time we are experts.
Here is a link that might help to a schemetic of the Si board. (At least as much as is known about it. I do not have the actual ic chip names but I am working on it.

http://www.bright.net/~jimshaffer/9.pdf

Good luck - keep up posted!

JIm
__________________
luckycat is offline   Reply With Quote
Old 12-28-2005, 07:12 PM   #9 (permalink)
n00b
 
Join Date: Dec 2005
Car:
Posts: 10
Photos:
djborya is on a distinguished road
chips

what does it matter u can take any chip anr re-flash it as long as u have the original values that are in the chip u are trying to copy... only way is to have a chip reader and flash instruments .I am by far am not a electronics major....but this is my knowledge of chip re-production.
Boris S.
1987 MB 420sel (unmolested)
1987 VW Cabrio 16v conversion Turbo
1985 MB 300d vegetable oil Fuel conversion
1991 325i (w/prblems)
djborya is offline   Reply With Quote
Old 01-01-2006, 06:50 AM   #10 (permalink)
n00b
 
Join Date: Dec 2005
Car:
Posts: 10
Photos:
djborya is on a distinguished road
speedo fixed

problem found w/the speedometor the wires at speed sensor are broken off at the connector.. If you have a problem w/ speedo check the wires by the sensor on rear differential, i am still working on the tach/econ gage ....
djborya is offline   Reply With Quote
Old 01-07-2006, 10:12 AM   #11 (permalink)
5th Gear Member
 
Join Date: May 2004
Location: NC
Car: Opening soon:
Posts: 1,118
Photos:
Starmavin is a jewel in the roughStarmavin is a jewel in the roughStarmavin is a jewel in the roughStarmavin is a jewel in the rough
What RPM tach do you have, you should have a 7000 rpm tach.
Starmavin is offline   Reply With Quote
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)
 
Thread Tools
Display Modes

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


Similar Threads
Thread Thread Starter Forum Replies Last Post
1984 325i 6cyl - 1991 325 6cyl im3d 3-Series (E21, E30) 2 03-21-2005 07:48 PM
FS: 1991 325i WA State - USA Karissachan Classifieds Sell & Buy 2 09-15-2004 12:01 AM
My 1991 325i dutchbmw Picture Showroom 22 05-09-2004 08:47 AM

Powered by vBadvanced CMPS v3.2.2

All times are GMT -5. The time now is 10:15 PM.



Powered by vBulletin® Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Content Relevant URLs by vBSEO 3.3.2
Garage Plus vBulletin Plugins by Drive Thru Online, Inc.