Vacuum Leak Cause bad MPG?
08-30-2013, 01:44 AM
#1
Member
Thread Starter
Join Date: Jun 2013
Location: Phoenix,Arizona
Posts: 130
Likes: 0
Received 0 Likes
on
0 Posts
Year: 1989
Model: Cherokee
Engine: 4.0L
Vacuum Leak Cause bad MPG?
Okay so i posted another thread about my bad fuel economy. i get about 12.7 MPG. i found a vacuum leak. The line running from the cruise control box to the vacuum booster pill looking thing. could that 1 leak have caused the worse MPG?
08-30-2013, 06:53 AM
#2
::CF Moderator::
Join Date: Aug 2011
Location: Prescott, Az
Posts: 43,876
Received 1,526 Likes
on
1,238 Posts
Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
08-30-2013, 08:01 AM
#3
Seasoned Member
Join Date: Jun 2011
Location: Key Peninsula, WA
Posts: 319
Likes: 0
Received 3 Likes
on
2 Posts
Year: 1997
Model: Grand Cherokee
Engine: 4.0
Where there was one vac leak there may be others. The vac reserve "pill" behind the front bumper is best if relocated under the coolant tank. Yank out all the excess crappy plastic vac line that runs up there and you'll eliminate a big source of leaks. Also check your intake manifold bolts. They tend to work loose over time and cause big vacuum leaks. O2 sensors get old and give poor readings to he computer which can affect mileage big time.
Best of luck!
Best of luck!
08-30-2013, 08:06 AM
#4
::CF Moderator::
Join Date: Aug 2011
Location: Prescott, Az
Posts: 43,876
Received 1,526 Likes
on
1,238 Posts
Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
Where there was one vac leak there may be others. The vac reserve "pill" behind the front bumper is best if relocated under the coolant tank. Yank out all the excess crappy plastic vac line that runs up there and you'll eliminate a big source of leaks. Also check your intake manifold bolts. They tend to work loose over time and cause big vacuum leaks. O2 sensors get old and give poor readings to he computer which can affect mileage big time.
Best of luck!
Best of luck!
Here's a photo for the OP.
Thread
Thread Starter
Forum
Replies
Last Post
xjwolfman
Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go here
8
08-26-2020 12:59 PM
NM-XJ
Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go here
18
10-23-2018 04:21 PM
shelby5041
Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go here
39
11-07-2015 01:22 AM
canada_man
Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go here
0
09-04-2015 11:05 AM
Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)