Tach cutting out at 4000 rpm. Why?
03-13-2006, 10:36 AM
#1
Racer
Thread Starter
Member Since: Jan 2005
Location: Birmingham AL
Posts: 492
Likes: 0
Received 0 Likes
on
0 Posts
Tach cutting out at 4000 rpm. Why?
I was pulling some sprints on the motor over the weekend and saw that my tach would reach about 4000 rpm and then completely cut out as in drop to near zero. Once the rpm dropped back just below it would show a solid reading. This is for a 1977 with a new distributor. What are the potential causes for that?
03-13-2006, 02:37 PM
#2
Did you install a new module with the distributor? Usually they cut out like that at a lower RPM, but I guess it's possible.
Hey Steve, will your car be ready to show at the Mid Alabama Corvette Club Spring Show? April 8th at the Cosco Parking lot.
My Car will be there, White 1977 in the club member section. You should think about joining the club. Send me a PM if you need more info.
Thom
Hey Steve, will your car be ready to show at the Mid Alabama Corvette Club Spring Show? April 8th at the Cosco Parking lot.
My Car will be there, White 1977 in the club member section. You should think about joining the club. Send me a PM if you need more info.
Thom
03-13-2006, 03:37 PM
#3
Racer
Thread Starter
Member Since: Jan 2005
Location: Birmingham AL
Posts: 492
Likes: 0
Received 0 Likes
on
0 Posts
Yes, new module with the dist.
I'm trying! That's why I've been posting so many questions lately.....final push to get her done! That and I promised the wife a nice fancy dinner once it's done and she's getting impatient!
I'm trying! That's why I've been posting so many questions lately.....final push to get her done! That and I promised the wife a nice fancy dinner once it's done and she's getting impatient!
03-13-2006, 04:19 PM
#4
Bad wire somewhere..... I think I misread your original post, maybe try jumpering the tach wire from dist. to Tach. Although I think there might be some kind of tach filter in the circuit... so maybe not a good idea! Do you know if it worked before the dist. swap?
03-13-2006, 10:30 PM
#5
Racer
Member Since: Nov 2004
Location: Granbury TX
Posts: 432
Likes: 0
Received 0 Likes
on
0 Posts
Tach Filter?
Originally Posted by steves_77vette
I was pulling some sprints on the motor over the weekend and saw that my tach would reach about 4000 rpm and then completely cut out as in drop to near zero. Once the rpm dropped back just below it would show a solid reading. This is for a 1977 with a new distributor. What are the potential causes for that?
03-14-2006, 09:50 AM
#6
Racer
Thread Starter
Member Since: Jan 2005
Location: Birmingham AL
Posts: 492
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by lucky76
Do you have the tach filter mounted on the intake manifold? The Tach wire goes through it before goint to the tach inself.
03-14-2006, 10:32 PM
#8
Drifting
My 80 started having the same problem however I had no time to trouble shoot since I have a track day this Saturday. I ended up going with an on dash tach for now just to get me through this. Funny thing is the new tach works fine and is tied into the wire between filter and cap (HEI).
Dave
Dave
