Tachometer

[cpo5969]

I have an 88, Automatic. All of the LED stuff works great,has never been repaired, the vehicle has about 190K and still going strong.

When I hit a bump my tach will come on and then go back to 0 and stay there until another bump.

The roads back here are awful. What can I do and how do I reconnect the tach? Thanks.

 

[wwood]

When my tach acted up it was only a loose wire connection to the pickup sensor. Check the thin wire connector that connects to the pickup on the distributor. (Not the large spark plug wires.)

 

[cpo5969]

Thanks

Thank you, let me go check the wire now.

 

[Eagle85C4]

Pickup sensor?

If you remove the coil from the top of the distributor you will find that the wire for the tach is attached to one side of the coil. What it does is take the pulses that the electronic ignition unit sends to the coil which it "amplifies" and distributes to the spark plugs and sends them to the tach circuit in the dash cluster which counts the pulses and displays the results on the lcd tach display.

Soooo soddy....no pickup sensor.... for the tach...at least there is not one on my 85....maybe there is on the later years or the LT-1, or 4 or 5...but not one the 84, 85,86,87,88 that I am aware of.

Now inside the distributor there is a pickup that is used to time the pulses for the coil...but if it is malfunctioning then you will not get spark plug fire when it should and your engine will run mighty rough...

 

[cpo5969]

Thanks Capt

Makes sense now, cause I could not find the thin wire....

Semper Fi

 

[RedRagTop]

My 88 has about 65,000K on it and no dash probs yet (knock) but what really impressed me was that you have 190K on yours and still pulling strong! I assume original powertrain? Hope I can pile those kinds of miles on my OE!

 

[Magmotor]

Can you check the voltage at the 32pin j-connector at the cluster?? Pin #C5 should be battery voltage w/engine running. Sounds like cold solder joint or wire. Can you remove your cluster? If you can, gently move wires back and forth, also press easly on j-connector...if it comes on, then at least your at the souce of the problem.