I have a problem that I've been noticing lately and believe it is electrical but not sure if tps or not. The problem is when I am idling for a long time the rpms will bounce around. The rpms only bounce if I'm in park or neutral. If I am in drive they will drop and come back up but I usually throw it in neutral before it has a chance to stall. It also occasionally does it when I'm driving but it's like it cuts of the throttle then gets back in it really hard. Some times you barely feel it and sometimes it puts me back in my seat. But it seems to on,y do it when warm. And I did check the tps voltage and it read .5v at closed and 3.5v at wide open. I thought that was good but not sure. I've replaced the tps a couple times before as well. So does it sound like a tps problem?

 

When's the last time you cleaned the throttle body - as in took it off the truck, pulled the IAC valve, and cleaned all the passages?

 

It's probably been a year or two

 

That's a good place to start.

 

cleaning the IAC is probably a good idea too.

 

I had a similar issue with my Dakota 4.7.
I let the engine idle and taped on the TPS lightly with a screwdriver RPM would change
replaced the TPS now all is good.

 

OP says he replaced the TPS. You are right though. When I had my idle problems, the TPS tested fine with a voltmeter. I cleaned the IAC and it didn't help till I replaced the TPS. Rock solid idle after that.

 

Yeah I will clean the throttle body soon and replace the tps as well. I just hate to cause it will be the fifth one very put on it in like 2 years. And another thino I was going to mention is that even from a dead stop when I put it to the floor and take off I've never hit 4000 rpm. It shifts out of first at 3800 and doesn't go any higher then that. I thought might be related to problem I first posted but not sure.

 

Never buy a cheap TPS always buy quality like airtx/wells the higher priced model or OEM. The cheap ones suck and have a short life

 

I wanted to update this instead of making a new fourm. Could the idle drop problem I have be fuel pump related? I've noticed it happens more when I am below half a tank and even more if I get below a quarter. And one time when I was below a quarter and the rpms started to drop my gas gauge quit working and would come back up real quick. I've also noticed I feel like the throttle response is better right after I get gas.