Tach Problem

[jlwelding]

On my 01 it jumps a little at idle, what's going on? I never payed to much atten. to it.

[98whitelightnin]

Can you hear the engine idle change or just the needle bounce? It seems normal for the most part, my truck never did it when it was an auto and now does it on occasion.

[rancherman]

which direction is it jumping? up, down, or both sides of idle rpm?... and by how far? Is it doing it only at cold start up? or when fully warmed up? Im right at the first stage of looking for the demon in mine... but it'll go from indicated rpm... to zero....back up to normal.I also have a crankshaft sensor code too..

[dripley]

Mine has always bounced a little with no change in the engine. By a little I mean only 10 rpm. It has done since it was new.

[CSM]

Mine has always bounced a little with no change in the engine. By a little I mean only 10 rpm. It has done since it was new.

My 02 has done the same. I recently put a timbos APPS in it and it smoothed out the tach and feel of the engine a bit. I almost wonder if my old worn APPS was stairstepping the voltage pretty badly, rather than a nice linear ramp.

[dripley]

My 02 has done the same. I recently put a timbos APPS in it and it smoothed out the tach and feel of the engine a bit. I almost wonder if my old worn APPS was stairstepping the voltage pretty badly, rather than a nice linear ramp.

I am running the Timbo apps on mine, but it never changed the tach bouncing. Mybe 25% of the time it sits steady the rest of the time it bounces a little. I have not really paid much attention to it since the engine idles smooth. Just got used to it over the years.

[Mopar1973Man]

Also running Timbo's APPS and still have a slight bounce to the tach. Nothing that bothers me so far. Now if we start talking about my injector misfire different story. (Time to clean again!)

[jlwelding]

Sorry, I just got back to topic. Yea it jumps about 10-20 rpm, dont hear eng. change and I too am running timbo. I have changed practically everything under the hood at one point or another and it still jumps. I thought I had it fixed with cam sensor but it started right back. It seems the cam sensor will stop it for a while but it will bounce shortly after install.Thanks Guys

[Rogan]

at least yours works.. LOL