HELP ASAP!!!

#1

I need some help guys. I picked up my car from the shop last night after getting the new motor put in. The tach and the oil temp gauge are INOP. I am not so much worried about the oil temp but could someone please tell me how to hook the tach up. The E30 is a new car to me and I don’t know its ins and outs. I have to register for the BMW Race School at Barber’s tonight and would really like to have a working tach this weekend. Any help or advise you could give would be great. Thanks, ALLEN

#2

Allen -

I assume these are aftermarket gauges that worked before the new engine and don’t work now? Do you still have the stock cluster and that tach is inop, too?

Steve D.

#3

Its an Autometer Tach and it did work before the new motor was put it. It is just pegged at 9g’s.

#4

There is no cluster og gauges. The other gauges are mounted to the cage bars and the tach is the only thing where the stock cluster would be.

#5

The tach is getting its signal from the coil. Make sure they didn’t install the tach wires backwards on the coil.

#6

Here’s the wiring guide.

http://www.autometer.com/download_instruction/470d.pdf

Travis is probably right, but in the end you’ve only got a handful of wires to worry about. Hot, switched hot, ground, and coil neg. If they connected the green wire to 12V that might do it too.

#7

Awesome. Thanks for the help guys. As a newbie I really appreciate all the help and advice everyone in the SE croud is willing to share.

#8

A tach is overrated. Just run up to where you feel the rev limiter kick in, then shift.

I’d be more worried about the oil pressure gauge.

#9

I have an oil pressure gague and it is working. the oil temp gauge is not working but it apperies to not be plumbed yet. another thing to do. lol

#10

I have an oil pressure gague and it is working. the oil temp gauge is not working but it apperies to not be plumbed yet. another thing to do. lol

#11

jlevie wrote:

Seems like both valvetrain and lap times suffer by banging off the rev limiter (even momentarily). But I agree with Jim that an inoperable tach wouldn’t keep me off track.

Steve D.

#12

Well, it won’t keep me off the track. No way. LOL I downloaded the wiring diagram for the tach.( Thanks Ranger) So I will try and troubleshoot it tonight after check in if it is not raining. The mechanic said he would come to the track tomorrow morning and fix it as well. So hopefully I should have it done tonight but if not then it will be taken care of in the morning.

#13

If you hooked the tach up wrong, just go down to the store and buy another. Unfortunately, you have toasted it. Chuck BTW, where are you this weekend?

#14

Hey Chuck. Sent you a PM.