Hasn't happened for a few days but on my drive from ny to fl a few times the rpms would get stuck at 2-3-4k rpms when letting off the gas.
Also when letting the revs drop it goes too low and shudders many times.
I know the shudder most people say is the MAP sensor.
I looked at the throttle cable and all and don't see any reasons for it to stick or anything.
Any suggestions? The shuddering has been going on for over a year now and is really starting to bother me. Rev sticking is a new issue.

 

i get the "shudders" when i have the battery unplugged and then i plug it back in and then the ecu is re-learning the car (supercharger, rr fpr, walbro fp, hfc, etc).

my guess would've been like yours, something regarding the throttle body, regarding the hanging rpms upon de-acceleration. good luck.

 

Yeah as far as the shudder I have not disconnected the battery or edu recently at all.
Anyone know if replacing the map sensor usually fixed that? It hardly ever stalls. I think maybe once in
the last year but still annoying.
Revs sticking maybe something due to long distance driving? Happened once since the drive down but happened most during the real long drive from ny to fl.

 

Definitely check to make sure the throttle cable is not sticking somewhere...check the return spring as well. It would probably be a good idea to clean the throttle body to make sure the butterfly valve isn't getting stuck.

If all those are good, then I would suspect the TPS. If you can check the volts over the range to make sure they fall within spec. The voltage reading should be in the vicinity of .30 volts at idle and in the vicinity of 4.5 volts at WOT. And the voltage should smoothly change as you open and close the throttle...no spots where it hangs or drops to 0.

 

Ok I'll have to get a multi meter.
As far as the shuddering would the best bet be to replace the map sensor?

 

Replacing the MAP for these kinds of issues is always a good idea. I had a similar issue (juddering and fuel cut offs randomly during accel or decel, especially when pulling away from lights in 1st and 2nd), mine too never stalled though. I did the map whack and ecu reset at the same time, so I don't know which was effective, probably both as I suddenly picked up a lot more midrange torque and the car ran better than it ever had during my ownership.

 

Yeah I've reset the ecu multiple times and did the map whack as well. Neither have made a difference.

 

Well haven't had a chance to get a multi meter yet. It happened again yesterday but seems to go away or lessen as soon as I turn the actually off. So it looks like that is contributing to the idling issue possibly. Would there possibly be an issue there? I know the AC slightly changes idling when turned on on all or most cars since it's run off a pulley.

 

when the revs stick at 4k, put your foot under the gas pedal and pull up. If the RPM's drop to normal its a mechanical issue (throttle cable/ throttle body)

 

Well the rev sticking hasn't happened again yet. The shuddering happens pretty much any time after driving a little while and with the ac on. As soon as I turn the ac off it gets better.