MPG with bad TCM

bigalpha

Moderator

Location

Tucson, AZ

• Sep 12, 2008

• #1

95 XJ, 4.5" lift, 31", stock gearing.

Bad TCM/TPS. I get ~11-13 mpg now.

How much do you think mileage will increase, if at all, when I fix this problem?

 

8

89xj

NAXJA Forum User

Location

aston,pa

• Sep 12, 2008

• #2

how do you know there bad? are you guessing or are you getting a CEL?

could be alot of things wrong if your getting bad milage?

tps affects shifting, not sure if you would get better mileage. how does it shift with stock gearing and 31" tires?

when was the last tune-up?

 

bigalpha

Moderator

Location

Tucson, AZ

• Sep 12, 2008

• #3

Typical symptons .. Jeep does not automatically shift on its own (A/T), but I can shift manually. In 'D', Jeep drives, but really slowly like it's in 4th.

The Tranny shifts fine. I just got the Jeep not too long ago, so I'm slowly working on the tune-up.

I was just curious how bad for gas mileage a bad TCM/TPS is. Like, if I get the problem fixed, will it boost mpg?

 

J

Jess

NAXJA Forum User

Location

Tennessee

• Sep 12, 2008

• #4

My 94 (31's and stock gears) is properly tuned and gets about 13.5-14.5 city and about 16.5 highway.....so not much better.

I have never heard of a TCM, do you mean TCU?

 

bigalpha

Moderator

Location

Tucson, AZ

• Sep 12, 2008

• #5

I guess mine is relatively comprable then. New plugs, etc should help a bit too.

TCM = TCU

 

srmitchell

NAXJA Forum User

Location

Mckinleyville (Humboldt) CA

• Sep 12, 2008

• #6

I would think so. My tcm is bad, and the mileage is below 10.

Usually I get 15. (City.)

 

bigalpha

Moderator

Location

Tucson, AZ

• Sep 12, 2008

• #7

Wow. I hope that whenever I can get my problem fixed, the mileage will get to around 15-17.