Jumping rpms

[connor98]

I've got a 5.7 1500 no modification, I noticed my rpms jump at idle. It doesn't go under 500 and doesn't go past 700. I just find it odd.

 

[tidefan1967]

How many miles on the clock? I would start by cleaning the throttle body and running some Redline SI-1 fuel injector cleaner for a couple tanks. A dirty throttle body/dirty/clogged fuel injectors make a hell of a difference in that department. That's all assuming that you don't any CEL's and then you would need to look further.

 

[16blackexpress]

Mine does the same thing from time to time. Interested in what gets said

 

[RoadRamblerNJ]

Mine does the same thing from time to time. Interested in what gets said

Completely random right? You never know when or why. Mine just stopped doing it one day. Never came back. Weird.

 

[16blackexpress]

Completely random right? You never know when or why. Mine just stopped doing it one day. Never came back. Weird.

Yes exactly. And with me having a FM muffler it’s very noticeable. I just put some redline in the gas tank and cleaned the TB but it really wasn’t dirty at all but I guess we will find out if it helps or not

 

[RoadRamblerNJ]

Yes exactly. And with me having a FM muffler it’s very noticeable. I just put some redline in the gas tank and cleaned the TB but it really wasn’t dirty at all but I guess we will find out if it helps or not

Yeah, I tried that too. Wasn't it. Damn truck was only a month or two old when it started. I never did find out 'cause it just one day stopped happening.

 

[RoadRamblerNJ]

I'll tell you what though this **** didn't happen in the 60's & 70's! If it was doing something funky, you found it (usually pretty quickly) and fixed it. Done.

I hate this voodoo ****. It is rather reliable, day to day though.

We forget how unreliable our "great" cars were. I know this, I don't carry a 60 lb. toolbox and extra parts around any more, LOL.