Car stumbles when cruising at 1500rpm

[BlackMetal]

Alright, I've been noticing a problem lately. This one highway to and from my job, cops sit there and bust people all day for breaking the 45mph limit on a road that seems like an expressway. So I got busted one of my first weekends working there. Since then, I keep it at 45. Problem is, if I cruise along doing 45 in Overdrive, I'm down around 1500rpm, and the car stutters. It's such a slight sensation, you really only notice it through the seat of your pants. You can just feel the car running rough. When I'm driving like that, I BARELY have my foot down on the gas. If I apply more throttle and get up to 1800-2000RPM, it goes away. If I get completely off the gas and let the RPM drop, it goes away. It really only happens during that very slight throttle application when I'm trying to maintain 45. My only uneducated guess would be a bad spot on the TPS that I don't notice at other times because that's the only situation where I have my foot so lightly on the gas. Or is the TCC confused because I'm probably a hair away from dropping back into 3rd at that point? Appreciate any help.

 

[onefastcar]

Mine does same thing just in between gears i believe, i really don't think its anything to worry about just keep it under or over that point.

 

[bholker]

Mine does that too. So slight that you barely notice it, but it's definately there, just like you describe. Mine's pretty intermittent when you get at the that 'wrong' speed.
Anyone out there got some input?

 

[terryjh6]

stumble

i think what you have is the exact speed that your overdrive is kicking in and out.. i've burnt 2 trans in 2 diffrent cars trying to maintain 45 here at the beach.. i keep my od for 50 and up, but that is guess... Terry

 

[BlackMetal]

i think what you have is the exact speed that your overdrive is kicking in and out.. i've burnt 2 trans in 2 diffrent cars trying to maintain 45 here at the beach.. i keep my od for 50 and up, but that is guess... Terry

Yeah...I figured maybe I was riding the line between 3rd and 4th gear and was pissing off the trans. I guess I'll either keep it in 3rd for that stretch of road, or bump it up to 50mph.

 

[turbo dave]

My 86 gn was having a similar problem. I could get mine to also do it in 3rd under very light throttle. I still had the original injectors in the car. I also was getting early knock and poor performance. After I replaced the injectors all the problems disapeared. I think the injectors were partially clogged or had very poor spray patterns. Just a thought if you have old injectors.