Small problem...please help
#1
Member
Thread Starter
Join Date: Jan 2011
Location: Virginia
Posts: 101
Likes: 0
Received 0 Likes
on
0 Posts
Year: 1999
Model: Cherokee
Engine: 4.0l
Small problem...please help
Ok so here is whats going on. I have a small miss fire, not a problem, The big issue is at around 45-55 its bucking. But I can still force a down shift out of it.
4.0l with an AW4.
Any help would be great thanks.
4.0l with an AW4.
Any help would be great thanks.
#2
Seasoned Member
Join Date: Dec 2008
Location: Burleson, TX
Posts: 311
Likes: 0
Received 0 Likes
on
0 Posts
Year: 1995
Model: Cherokee
Engine: 4.0L
Does it do it when in neutral and you rev it to a certain rpm or just while driving. Also how many miles and have you done any maintenance.
#4
Seasoned Member
Join Date: Nov 2010
Location: N.Y.
Posts: 279
Likes: 0
Received 0 Likes
on
0 Posts
Year: 1999
Model: Cherokee
Engine: 4.0 L
Tune up sounds like it is in order.
Plugs,wires,air and fuel filter,distributor cap and rotor etc.
For me the cap and rotor is a big one because many people over look this during a tune up.I even did once on my s-15 jimmy,the thing was missing like crazy and I assumed the worst after doing the above mentioned items.I finally took a look at the cap and rotor and the contacts were burnt all to heck.Installed new and the thing ran like new!
When doing the plugs keep them in order of which cylinder they came out of and take a good look at them this way if something else is actually wrong you can use the condition of the plugs to help determine the problem and which cylinder is the culprit.
Plugs,wires,air and fuel filter,distributor cap and rotor etc.
For me the cap and rotor is a big one because many people over look this during a tune up.I even did once on my s-15 jimmy,the thing was missing like crazy and I assumed the worst after doing the above mentioned items.I finally took a look at the cap and rotor and the contacts were burnt all to heck.Installed new and the thing ran like new!
When doing the plugs keep them in order of which cylinder they came out of and take a good look at them this way if something else is actually wrong you can use the condition of the plugs to help determine the problem and which cylinder is the culprit.
Last edited by Spoonman; 01-28-2011 at 11:21 AM.
#6
Seasoned Member
Join Date: Nov 2010
Location: N.Y.
Posts: 279
Likes: 0
Received 0 Likes
on
0 Posts
Year: 1999
Model: Cherokee
Engine: 4.0 L
#7
CF Veteran
Join Date: Sep 2010
Location: Milwaukee, WI
Posts: 21,168
Likes: 0
Received 5 Likes
on
5 Posts
Year: 1987
Engine: Check
If you have a fuel delivery problem and you are running lean it'll show on the plugs. They'll appear white/gray.
A motor uses more fuel at the same RPM when its under load. Free revving the motor doesn't reproduce the same senario that is created when you are actually moving the truck via the motor.
Loose, crappy explination....
3000rpm at free rev, no movement may use 1/2 gallon of fuel over an hour.
3000rpm under load while moving the truck may use a whole gallon over an hour.
Not exact numbers, but you get my point hopefully.
The fuel pump may be able to supply the fuel for free revs, but under load my not be able to keep up.
A motor uses more fuel at the same RPM when its under load. Free revving the motor doesn't reproduce the same senario that is created when you are actually moving the truck via the motor.
Loose, crappy explination....
3000rpm at free rev, no movement may use 1/2 gallon of fuel over an hour.
3000rpm under load while moving the truck may use a whole gallon over an hour.
Not exact numbers, but you get my point hopefully.
The fuel pump may be able to supply the fuel for free revs, but under load my not be able to keep up.
Last edited by Gee oh Dee; 01-28-2011 at 11:36 AM.
Trending Topics
#8
Seasoned Member
Join Date: Nov 2010
Location: N.Y.
Posts: 279
Likes: 0
Received 0 Likes
on
0 Posts
Year: 1999
Model: Cherokee
Engine: 4.0 L
Tune up sounds like it is in order.
Plugs,wires,air and fuel filter,distributor cap and rotor etc.
For me the cap and rotor is a big one because many people over look this during a tune up.I even did once on my s-15 jimmy,the thing was missing like crazy and I assumed the worst after doing the above mentioned items.I finally took a look at the cap and rotor and the contacts were burnt all to heck.Installed new and the thing ran like new!
When doing the plugs keep them in order of which cylinder they came out of and take a good look at them this way if something else is actually wrong you can use the condition of the plugs to help determine the problem and which cylinder is the culprit.
Plugs,wires,air and fuel filter,distributor cap and rotor etc.
For me the cap and rotor is a big one because many people over look this during a tune up.I even did once on my s-15 jimmy,the thing was missing like crazy and I assumed the worst after doing the above mentioned items.I finally took a look at the cap and rotor and the contacts were burnt all to heck.Installed new and the thing ran like new!
When doing the plugs keep them in order of which cylinder they came out of and take a good look at them this way if something else is actually wrong you can use the condition of the plugs to help determine the problem and which cylinder is the culprit.
You may be dealing with a fuel or TPS issue
#10
Seasoned Member
Join Date: Nov 2010
Location: N.Y.
Posts: 279
Likes: 0
Received 0 Likes
on
0 Posts
Year: 1999
Model: Cherokee
Engine: 4.0 L
Thread
Thread Starter
Forum
Replies
Last Post
apac020
Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go here
7
09-29-2015 09:40 AM
Snajo
Other Vehicles. Other Jeep models & cars and trucks of other makes
0
09-26-2015 11:54 PM
Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)