Help needed- Irratic Tach @ WOT

[pgoffner]

I need some expertise from you guys. Whenever I go WOT my Ty will studder, the tach flops around, all the dummy lights flash on and off, the volt meter reads low and the truck dies half the time. What the heck is this? Can anyone point me in the right direction to trace this to a cause.

 

[Ty0279]

IGNITION

Use the "search" feature at the top of the page. Do a search for: tach AND flutter :tup:

 

[pgoffner]

Just did a search. Sorry guys :-?

 

[InvisiBill]

Since you have all sorts of other stuff with it (including low voltage), it could be your alternator also/instead.

 

[SY2932]

Since you have all sorts of other stuff with it (including low voltage), it could be your alternator also/instead.

Ditto. Our trucks don't respond well at WOT with anything less than 13 volts on tap... 13.4 volts or higher if you can muster it is even better. Outside of the anemic voltage, get accustomed to replacing the plugs (AC CR42TS or NGK UR5), wires (Taylor Spiro Pros or the like) and cap rotor (Conrad DR2012G) ANYTIME you get tach flutter at WOT.

 

[pgoffner]

I have a set of plugs , wires, cap and rotor ready to be installed. I already put a 160 amp alternator on a few days ago so I dont believe that its a voltage issue.

When installing a new cap and rotor, do you need to re-set the timing every time? Sorry if this is a dumb question, but I'm new to this. Thanks.

 

[SY2932]

When installing a new cap and rotor, do you need to re-set the timing every time? Sorry if this is a dumb question, but I'm new to this. Thanks.

No you don't but if you have to adjust your timing, you WILL have to address this wire under your dash on the passenger side:

"The "tan wire with a black stripe" that everyone can't find when attempting to set their timing. Wire is under the carpet on the passenger side below the heater box. It is disconnected to set the timing, then reconnected."

 

[Mike V]

A good quality cap and ignition wire set will cure the shudder 8 of 10 times. It take more zap to jump the plug gap as combustion pressures rize. Old wires often have too much resistance or cracked insulation that cause problems under boost. Not sure of your climate, but is the problem noticably worse in damp conditions? That is a sure sign of ignition wire issues.
Cheers,
Mike V

 

[PPI Typhoon]

My tach flutter was lessened by my cap and rotor, but solved completely with a new ignition module. :2cents: