Running rough and backfiring
08-29-2016, 01:30 PM
#1
Newbie
Thread Starter
Join Date: Aug 2016
Posts: 3
Likes: 0
Received 0 Likes
on
0 Posts
Year: 1990
Model: Cherokee
Engine: 4.0L inline 6
Running rough and backfiring
I have a 1990 jeep Cherokee it's been having problems. When I start up the engine after it hasn't been ran for a few hours, it cranks for a while before it finally starts. It runs extremely rough and sputters. If you drive it that way it backfires and has an extreme loss of power. Also bad fuel mileage. Also has an extremely low idle. I'm not kidding it is probably 200rpms I have to put my foot on the gas just to keep it running. After the engine heats up it finally smooths out slowly.
Things I've done to fix it:
Spark plugs/wires
Distributor cap/ rotor
Cleaned throttle body
Replaced iac sensor
Checked map sensor
Checked tps sensor
Checked fuel pump and fuel lines (fuel pressure read 39psi)
I just need help fixing the problem
Things I've done to fix it:
Spark plugs/wires
Distributor cap/ rotor
Cleaned throttle body
Replaced iac sensor
Checked map sensor
Checked tps sensor
Checked fuel pump and fuel lines (fuel pressure read 39psi)
I just need help fixing the problem
08-29-2016, 04:52 PM
#2
CF Veteran
Break/leak in the exhaust. Happened to me when my exhaust mani cracked. Again when my muffler went bad. Had to do with the O2 sensors getting bad readings and drowning the engine.
Might check those also, and the wiring going to them. They might be giving false readings.
Good luck!
Might check those also, and the wiring going to them. They might be giving false readings.
Good luck!
08-29-2016, 04:54 PM
#3
CF Veteran
Might also, if you're new to jeeps or this one is new to you, refresh your grounds. (Clean your wire contact points at the bolts.)
Cruiser54 wrote the Bible on it. Check his personal website by googling it.
It NEVER hurts. Maintenence is King.
Cruiser54 wrote the Bible on it. Check his personal website by googling it.
It NEVER hurts. Maintenence is King.
08-29-2016, 05:09 PM
#4
::CF Moderator::
Join Date: Aug 2011
Location: Prescott, Az
Posts: 43,875
Received 1,526 Likes
on
1,238 Posts
Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
I have a 1990 jeep Cherokee it's been having problems. When I start up the engine after it hasn't been ran for a few hours, it cranks for a while before it finally starts. It runs extremely rough and sputters. If you drive it that way it backfires and has an extreme loss of power. Also bad fuel mileage. Also has an extremely low idle. I'm not kidding it is probably 200rpms I have to put my foot on the gas just to keep it running. After the engine heats up it finally smooths out slowly.
Things I've done to fix it:
Spark plugs/wires
Distributor cap/ rotor
Cleaned throttle body
Replaced iac sensor
Checked map sensor
Checked tps sensor
Checked fuel pump and fuel lines (fuel pressure read 39psi)
I just need help fixing the problem
Things I've done to fix it:
Spark plugs/wires
Distributor cap/ rotor
Cleaned throttle body
Replaced iac sensor
Checked map sensor
Checked tps sensor
Checked fuel pump and fuel lines (fuel pressure read 39psi)
I just need help fixing the problem
08-29-2016, 10:46 PM
#7
::CF Moderator::
Join Date: Aug 2011
Location: Prescott, Az
Posts: 43,875
Received 1,526 Likes
on
1,238 Posts
Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
Thread
Thread Starter
Forum
Replies
Last Post
jackson1714
Stock Grand Cherokee Tech. All ZJ/WJ/WK Non-modified/stock questions go here!
23
06-01-2019 05:36 PM
punkbug83
Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go here
6
10-26-2017 01:24 PM
greenbastard96
Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go here
9
08-29-2016 01:35 PM
Ditchdigger
Stock Grand Cherokee Tech. All ZJ/WJ/WK Non-modified/stock questions go here!
1
03-26-2016 06:19 AM
jeep187
Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go here
5
01-09-2009 04:09 PM
Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)