tach falling to zero

[mclark]

Have a 1994 sho auto, while driving to church the rpm fell to zero, car would not accelerate. RPM registers again a few seconds later and able to accelerate. On my home from church RPM drops but not to zero. Had some sputtering at time after cranking. Any ideas Thanks a lot.

 

[93markVIII]

it just means the hamster that runs in the wheel is getting a little tired.

also, sounds like a dying cam sensor.

 

[SHOdded]

Though there might be crank position sensor involvement (CKS), I'd check the cam position sensor (CPS) first. Sometimes it can be cleaned off & reused (problem happens due to oil soak), but longterm fix is to replace it. Use the seal from National, not FelPro, even if they have the same part number. The FelPro tends to fail.

 

[BaySHO Performance]

Won't have to replace the seal of course if it's not leaking and all you have to do is replace the cam sensor.

I also have had problems with the Felpro cam seals. Unless one is very careful, the rubber will split from the outside of the seal.

Part number for the National Seals?

 

[SHOdded]

1213N, I believe.

 

[mclark]

Hey, thanks guys for the info i will update u asap.

 

[rubydist]

that symptom is a cam sensor issue, not a crank sensor issue.

there are only a couple of things that affect the tach functioning: cam sensor, pcm, wiring and the actual tach gauge.

 

[mclark]

Hey guys thanks for the info, i replaced the camshaft sensor and the SHO tach fell to zero again , also the car just shut off but started several minutes later.Is there anything else to check. Thanks.

 

[NEp8ntballer]

check the wiring for the cam sensor

 

[AREA 91]

I have found a broken wire in the harness 2 inches from the cam sensor plug. Check there.

 

[zoomlater]

Check to see if there are two of those orange seals between the plug and cam sensor. The last time I replaced mine, the seal came out with the plug (even though there is one already in the cam sensor), I was able to make the connection for months until it finally started missing, hard start, no tach.

 

[Toolman]

that symptom is a cam sensor issue, not a crank sensor issue.

there are only a couple of things that affect the tach functioning: cam sensor, pcm, wiring and the actual tach gauge.

And DIS.

 

[mclark]

Hey guys thanks 4 all the info, I took the SHO to a friend and had him to replace the crank sensor for good measure since i have had the SHO for 18 years. When he made it to the crank sensor he noticed one of the screws that holds the sensor was located in the bottom of the timing cover and the sensor had slightly turned. He installed the new sensor, put every thing back together and the SHO is good to go. Thanks for the support.