High RPMS, Bad MPG, Hoping Tanny is Okay
#1
Junior Member
Thread Starter
Join Date: Mar 2017
Posts: 77
Likes: 0
Received 0 Likes
on
0 Posts
Model: Cherokee
High RPMS, Bad MPG, Hoping Tanny is Okay
I recently had my NSS replaced, but the dealer forgot to reset the ECU so I have the check engine light on and am getting high RPMS everywhere. While my reverse lights are working now (post nss), I cannot start in neutral and at 50mph my RPM is over 2,000. I think the switch still needs adjustment and I am going back to the mechanic today at lunch. It feels like the entire transmission is hanging on higher rpms than it should. It is shifting at around 2,500 rpm and then settling down at 2,000 instead of a healthy 1,500 or so. My tires are 235. I haven't seen much on how NSS can affect the RPMS besides blocking 4th gear/OD. But it seems to be switching past 3rd. I am also getting 12-13 mpg and it's killing me.
Any other trouble shooting topics I can bring up at the shop today? I'd love to be able to take this thing on the highway..
Any other trouble shooting topics I can bring up at the shop today? I'd love to be able to take this thing on the highway..
#4
Junior Member
Thread Starter
Join Date: Mar 2017
Posts: 77
Likes: 0
Received 0 Likes
on
0 Posts
Model: Cherokee
#6
CF Veteran
The detent cable has nothing to do with throttle response. It controls when the trans shifts. If it is too tight, it think you are always hard on the throttle. And I believe if it is way too tight, it will never shift in to 4th.
#7
Senior Member
Join Date: Jan 2017
Location: Central KS
Posts: 539
Likes: 0
Received 2 Likes
on
2 Posts
Year: 1996
Model: Cherokee
Engine: 4.0
NSS could certainly be preventing torque converter lockup AKA OD. Loss of which will certainly cause you to run 300-400 rpm higher than you should. Also IME causes the trans to work harder increasing temps.
Trending Topics
#8
Junior Member
Thread Starter
Join Date: Mar 2017
Posts: 77
Likes: 0
Received 0 Likes
on
0 Posts
Model: Cherokee
Alright so this is getting messy. The shob is claiming the NSS (bought from ebay) is no good and they have tried adjusting it multiple ways to get it fit correctly and it won't fit perfectly to where it starts in neutral or "pulls in 1st gear only". Reverse lights work the check engine lights keep returning after 30 seconds. I don't know whether to make a claim to the ebay company or try something else. This NSS switch has been a major pain for the last few months. I will have to get the codes again but this is a money pit right now.
#10
Junior Member
Thread Starter
Join Date: Mar 2017
Posts: 77
Likes: 0
Received 0 Likes
on
0 Posts
Model: Cherokee
Well, they cleared the codes and she's driving pretty normal. Hit 60 real quick and it stuck right at 2,000 rpm. I think when (hopefully if) the check engine light comes on, the RPMs at 50-60 seem to be more like 2500. Strange. Dependent on the check engine light being reset? I think I may get a code reader and keep resetting for the short time depending on what it does from here. I'm encouraged to see it behaving normally for now.
They took the original NSS off a couple weeks ago and probably threw it away.
They took the original NSS off a couple weeks ago and probably threw it away.