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Topic: Problem with Tach (Read 308 times) previous topic - next topic

Problem with Tach

Anyone know what is causing my Tach to do this? I have the video link below.
Thanks

Tach Video
Zack & Ginny Methvin
1998 U270 36' WTFE
Build# 5242 (E-25 code)
FMCA# 548390
Longview, Texas

Re: Problem with Tach

Reply #1 –
It looks to me like that is the normal start up sequence when the ignition switch is energized, but that there is no tach signal present. That can happen when the dash tach signal wire has become disconnected. Ours does the same thing but there is no delay when you energize the ignition switch. I haven't as yet found the dash tach signal lead which I believe is somewhere on top of the transmission. I would love to fix it, but since I use VMSPC to monitor the systems, it hasn't been a high enough priority to address considering the competing priorities vying for my time.
Quote from: Zack & Ginny –
Anyone know what is causing my Tach to do this? I have the video link below.
Thanks

Tach Video
The selected media item is not currently available.
Don & Tys
1999 U270 3602 WTFE #5402
Xtreme Stage 1 w/Headlight, Step Conversion, etc.
2009 Honda Fit Sport with Navi
Freedom is NOT "just another word for nothing left to lose"... with apologies to Kris Kristofferson

Re: Problem with Tach

Reply #2 –
Quote from: Don & Tys –
It looks to me like that is the normal start up sequence when the ignition switch is energized, but that there is no tach signal present. That can happen when the dash tach signal wire has become disconnected. Ours does the same thing but there is no delay when you energize the ignition switch. I haven't as yet found the dash tach signal lead which I believe is somewhere on top of the transmission. I would love to fix it, but since I use VMSPC to monitor the systems, it hasn't been a high enough priority to address considering the competing priorities vying for my time.

Thanks Don
Do you think this could be something as simple as a dirty connection? I have checked the sensor on the bellhousing and all the wires are connected and look good. It does this all the time in intervals of every 15-20 seconds.
Zack & Ginny Methvin
1998 U270 36' WTFE
Build# 5242 (E-25 code)
FMCA# 548390
Longview, Texas

Re: Problem with Tach

Reply #3 –
Have you ohmed out the wire from the sender to the tach. Looks like it is not getting a signal. I don't remember how to check the clearance between the flywheel and the sensor. Something like screw it in with the engine not running until contact and then back it back out maybe one turn. If there is too much clearance it will not work.
previous 1984 35 ft ORED 250 HP 3208 Cat       
previous 1998 40 ft U295 CAI 325 hp Cummins
previous 2003 40 Ft u320 build #6140 450 Cummins M11.                                                         
1999 Mazda Miata
Ron, Nancy, Tipper the cat, Max The dog
1997 U 270 36 ft build number 5174 8.3 Cummins

Re: Problem with Tach

Reply #4 –
Quote from: red tractor –
Have you ohmed out the wire from the sender to the tach. Looks like it is not getting a signal. I don't remember how to check the clearance between the flywheel and the sensor. Something like screw it in with the engine not running until contact and then back it back out maybe one turn. If there is too much clearance it will not work.


I have not tried that yet but I will, thanks Ron
Zack & Ginny Methvin
1998 U270 36' WTFE
Build# 5242 (E-25 code)
FMCA# 548390
Longview, Texas

Re: Problem with Tach

Reply #5 –
On my 98 u320 there are 2 diagnostic buttons under dash hood that if pushed can cause tach not to work.
1998 u320 3600 build 5200