low RPMs

[dizdak]

ok, seems every time i start the truck lately another issue is developed... last couple times i have started the truck it shows that it is only idling at about 300 rpms, and takes a while before they pick up and stay where they usually run.. also according to the tach there is a little fluctuation, maybe 50-75rpm quick drop then back up (like a v8 with a cam)... doesn't really feel like its running bad, not noticing any sluggishness or studders under throttle..selling the truck has been on my mind and getting more so each time i drive it!

 

[jaluhn83]

Does it feel like it's idling that low? If it was you'd be able to feel it.

My guess is your tach is just reading low. It's quite common for the tachs on these to read low or be finicky. Might try removing the sensor and cleaning the face - sometimes they'll get enough gunk on the face to cause inaccurate readings.

 

[dizdak]

no it doesn't feel like its idling that low..i am thinking and hoping its just a tach issue... by the time i got a few miles down the road it was back to normal..maybe just a sticky tach, the truck probably gets started once a week, maybe twice.. and actually driven maybe once every 2 weeks..

 

[hallgren87idi]

is it a stock tach? cuz mine didnt work at all, except when i was cranking. so i took a sensor off a parts motor my buddy had, and it worked great for about a month, now it will work for the first 10 mins of startup, then read maybe 2 grand when im doin 70, which should be like 3200 lol

 

[Kevin 007]

On the tach sensor, to the right of the injection pump, there are two wires leaving the sensor. They usually break or become weak with all the vibration. I ALWAYS put a little epoxy or JB weld around the two wires right at the sensor to prevent vibration. Works every time..... A cheap alternative to buying a new sensor every 10 years or whenever the wire fall out.

 

[dizdak]

thanks Kevin, i will look that over tonight.. i may have knocked them recently even while working on the vacuum pump...

 

[Kevin 007]

Its bound to happen sooner or later. Just not a very good location as they often get stepped on/leaned on or whatever when working on engine.