89 cherokee running bad
Newbie
Joined: Jan 2012
Posts: 9
Likes: 0
From: Stuart, FL
Year: 1990
Model: Cherokee
Engine: 4.0
Yes, I have changed every parts that comes off the motor! Even the distributor! Ecu, plugs wires, fuel pump, fuel filter, fuel regulator, injectors, throttle body, tps, coil, map, and all other sensors on motor. Except egr on the side of the intake and the knock sensor those r the only things I can think of that I didn't try.... very annoying! Thanks for your replies!
::CF Moderator::
Joined: Aug 2011
Posts: 43,971
Likes: 1,579
From: Prescott, Az
Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
Ever done this?
TESTING THE EGR VALVE FOR 87-90 4.0 ENGINE
Valve Opening Test
1) With engine at normal operating temperature and at idle,
rapidly open and close throttle. Open throttle sufficiently to obtain
at least 1500 RPM. Movement should be noticed in EGR diaphragm.
2) If diaphragm does not move, probable causes are: faulty
vacuum signal to EGR, defective EGR diaphragm or defective
backpressure sensor diaphragm (if equipped), or leaks in vacuum lines
or connections.
Valve Closing Test
1) With engine at normal operating temperature and at idle,
manually depress EGR valve diaphragm. RPM should immediately drop,
indicating that EGR valve is not leaking and had been properly cutting
off exhaust gas flow at idle.
2) If there is no change in RPM and engine is idling
properly, exhaust gases are not reaching combustion chamber. Check for
plugged passage between EGR valve and intake manifold.
3) If engine idles poorly and RPM is not greatly affected by
manually moving diaphragm up, EGR valve is not closing off exhaust gas
flow. Check for carbon between pintle, leaking EGR valve gasket or bad
EGR valve.
***************
TESTING THE EGR VALVE FOR 87-90 4.0 ENGINE
Valve Opening Test
1) With engine at normal operating temperature and at idle,
rapidly open and close throttle. Open throttle sufficiently to obtain
at least 1500 RPM. Movement should be noticed in EGR diaphragm.
2) If diaphragm does not move, probable causes are: faulty
vacuum signal to EGR, defective EGR diaphragm or defective
backpressure sensor diaphragm (if equipped), or leaks in vacuum lines
or connections.
Valve Closing Test
1) With engine at normal operating temperature and at idle,
manually depress EGR valve diaphragm. RPM should immediately drop,
indicating that EGR valve is not leaking and had been properly cutting
off exhaust gas flow at idle.
2) If there is no change in RPM and engine is idling
properly, exhaust gases are not reaching combustion chamber. Check for
plugged passage between EGR valve and intake manifold.
3) If engine idles poorly and RPM is not greatly affected by
manually moving diaphragm up, EGR valve is not closing off exhaust gas
flow. Check for carbon between pintle, leaking EGR valve gasket or bad
EGR valve.
***************
Newbie
Joined: Aug 2011
Posts: 29
Likes: 0
i know it has been virtually a month since anyone has replied to this post but if someone could help me with a relevant issue that would be great.
ok acceleration fine deceleration fine idle fine however when at cruising speed with a steady foot on the gas pedal the Jeep spits sputters misses and sounds like s**t! any ideas?
1989 cheroke 4.0L renix automatic. and cruiser i have done the ground clean up gonna buy new wires like you suggested (was on the to do list anyways) adjusted the TPS however i cannot achieve proper voltage on both square and flat plug. could this be the problem???? installed new TPS but think it was junk cause jeep stopped shifting all together. so as it stands the old TPS is back in and voltage for the tranny is good but engine is lacking just a little. simply put HELP!!!!!!
THANK YOU!!
ok acceleration fine deceleration fine idle fine however when at cruising speed with a steady foot on the gas pedal the Jeep spits sputters misses and sounds like s**t! any ideas?
1989 cheroke 4.0L renix automatic. and cruiser i have done the ground clean up gonna buy new wires like you suggested (was on the to do list anyways) adjusted the TPS however i cannot achieve proper voltage on both square and flat plug. could this be the problem???? installed new TPS but think it was junk cause jeep stopped shifting all together. so as it stands the old TPS is back in and voltage for the tranny is good but engine is lacking just a little. simply put HELP!!!!!!
THANK YOU!!
Member
Joined: Sep 2011
Posts: 248
Likes: 0
From: Oklahoma
Year: 1994
Model: Cherokee
Engine: 4.0
Originally Posted by daletucker
i know it has been virtually a month since anyone has replied to this post but if someone could help me with a relevant issue that would be great.
ok acceleration fine deceleration fine idle fine however when at cruising speed with a steady foot on the gas pedal the Jeep spits sputters misses and sounds like s**t! any ideas?
1989 cheroke 4.0L renix automatic. and cruiser i have done the ground clean up gonna buy new wires like you suggested (was on the to do list anyways) adjusted the TPS however i cannot achieve proper voltage on both square and flat plug. could this be the problem???? installed new TPS but think it was junk cause jeep stopped shifting all together. so as it stands the old TPS is back in and voltage for the tranny is good but engine is lacking just a little. simply put HELP!!!!!!
THANK YOU!!
ok acceleration fine deceleration fine idle fine however when at cruising speed with a steady foot on the gas pedal the Jeep spits sputters misses and sounds like s**t! any ideas?
1989 cheroke 4.0L renix automatic. and cruiser i have done the ground clean up gonna buy new wires like you suggested (was on the to do list anyways) adjusted the TPS however i cannot achieve proper voltage on both square and flat plug. could this be the problem???? installed new TPS but think it was junk cause jeep stopped shifting all together. so as it stands the old TPS is back in and voltage for the tranny is good but engine is lacking just a little. simply put HELP!!!!!!
THANK YOU!!
Newbie
Joined: Aug 2011
Posts: 29
Likes: 0
Well unfortunately mine has no tach. I know sad to say. However I can be going any speed really and let off the throttle enough to the load off the engine but maintain my speed and it'll do it. No matter my speed. Up to about 70-75-80 or so. Very confusing.
Newbie
Joined: Aug 2011
Posts: 29
Likes: 0
i can check and see but i do not think that i do. by indexed what per say do you mean? honestly i think it did start shortly after or right before i did my tune up. i put autozone (i know i know) duralast gold cap and rotor, bosch premium wire set, and i decided to try the E3 spark plugs. it is a little more peppy but the steady throttle issue is still there. so let me know what you got in mind i am all ears. well ears eyes hands feet and well i am all here and listening. LOL i'm sorry just got off work and feel goofy. thanks.
::CF Moderator::
Joined: Aug 2011
Posts: 43,971
Likes: 1,579
From: Prescott, Az
Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
Really should have an old distributor cap to cut up to verify this.
Make a mark straight down from #1 terminal of the cap to the dizzy housing. Bring the engine to #1 TDC using the harmonic balancer. Remove the dizzycap. Where is the rotor pointing in relation to the mark?
Make a mark straight down from #1 terminal of the cap to the dizzy housing. Bring the engine to #1 TDC using the harmonic balancer. Remove the dizzycap. Where is the rotor pointing in relation to the mark?
Newbie
Joined: Aug 2011
Posts: 29
Likes: 0
ok hey just an update real quickly. if you would like to check out his video i just recorded of the jeep going down the road listen to the ticking noise that is the crack in the exhaust manifold and it best accentuates the missing out noise i am talking about. it is really noticeable around the 30 second mark. and at the end i stop and take off with no hesitation. i am still looking for my old cap. i have an idea i just gotta dig. then off to the next hard part and that is getting the jeep to TDC. my harmonic balancer does not have very good markings if any at all. LOL