intermittent stalling

[quote:a8fa377faf="fireball2889"]i have a Jeep Cherokee with 126,000 miles with a 4.0L inline 6. my problem is while driving sometimes between 10- 30 mph the rpms will suddently drop back to idle without me letting of the gas pedal, but if u push the gas pedal down farther the rpms will kick up and the truck will go again i have replaced the tps sensor and the air temperature sensor and cleaned the entire throttle body and have had the fuel system professionally cleaned and these have made the problem a little bit better however i have no clue as to what is causeing this problem

Thx
Matt[/quote:a8fa377faf]

Hey Matt,
What year is that Cherokee? You describe an idle issue. Does the vehicle actually stall? Let me know!

Chris

[quote:2fb8ec6dc1="carundell"][quote:2fb8ec6dc1="fireball2889"]i have a Jeep Cherokee with 126,000 miles with a 4.0L inline 6. my problem is while driving sometimes between 10- 30 mph the rpms will suddently drop back to idle without me letting of the gas pedal, but if u push the gas pedal down farther the rpms will kick up and the truck will go again i have replaced the tps sensor and the air temperature sensor and cleaned the entire throttle body and have had the fuel system professionally cleaned and these have made the problem a little bit better however i have no clue as to what is causeing this problem

Thx
Matt[/quote:2fb8ec6dc1]

Hey Matt,
What year is that Cherokee? You describe an idle issue. Does the vehicle actually stall? Let me know!

Chris[/quote:2fb8ec6dc1]

Hey Chris
its a 1997 and it doesnt stall but while driving it will just drop back to idle for no apparent reason but ive been tinkering and if u put an octane booster or a fuel cleaner in it, it will only hesitate slightly then go instead of dropping back to idle

[quote:7668e475ac="fireball2889"][quote:7668e475ac="carundell"][quote:7668e475ac="fireball2889"]i have a Jeep Cherokee with 126,000 miles with a 4.0L inline 6. my problem is while driving sometimes between 10- 30 mph the rpms will suddently drop back to idle without me letting of the gas pedal, but if u push the gas pedal down farther the rpms will kick up and the truck will go again i have replaced the tps sensor and the air temperature sensor and cleaned the entire throttle body and have had the fuel system professionally cleaned and these have made the problem a little bit better however i have no clue as to what is causeing this problem

Thx
Matt[/quote:7668e475ac]

Hey Matt,
What year is that Cherokee? You describe an idle issue. Does the vehicle actually stall? Let me know!

Chris[/quote:7668e475ac]

Hey Chris
its a 1997 and it doesnt stall but while driving it will just drop back to idle for no apparent reason but ive been tinkering and if u put an octane booster or a fuel cleaner in it, it will only hesitate slightly then go instead of dropping back to idle[/quote:7668e475ac]

Hey Matt,
Interesting problem .... I would start w/ some of the basics first ........ check tune up, a clogged fuel filter etc ....... some other things would be a faulty O2 sensor. Is your check engine light on or flashing? if so most major auto parts suppliers offer a free scan. If you do this please post back w/ the codes and their description. Let me know!

Chris

[quote:febd901713="carundell"][quote:febd901713="fireball2889"][quote:febd901713="carundell"][quote:febd901713="fireball2889"]i have a Jeep Cherokee with 126,000 miles with a 4.0L inline 6. my problem is while driving sometimes between 10- 30 mph the rpms will suddently drop back to idle without me letting of the gas pedal, but if u push the gas pedal down farther the rpms will kick up and the truck will go again i have replaced the tps sensor and the air temperature sensor and cleaned the entire throttle body and have had the fuel system professionally cleaned and these have made the problem a little bit better however i have no clue as to what is causeing this problem

Thx
Matt[/quote:febd901713]

Hey Matt,
What year is that Cherokee? You describe an idle issue. Does the vehicle actually stall? Let me know!

Chris[/quote:febd901713]

Hey Chris
its a 1997 and it doesnt stall but while driving it will just drop back to idle for no apparent reason but ive been tinkering and if u put an octane booster or a fuel cleaner in it, it will only hesitate slightly then go instead of dropping back to idle[/quote:febd901713]

Hey Matt,
Interesting problem .... I would start w/ some of the basics first ........ check tune up, a clogged fuel filter etc ....... some other things would be a faulty O2 sensor. Is your check engine light on or flashing? if so most major auto parts suppliers offer a free scan. If you do this please post back w/ the codes and their description. Let me know!

Chris[/quote:febd901713]

Hey Chris
no my check engine light is not flashing the truck has brand new fuel fiter, O2 sensor, spark plugs, distributer cap and rotor, and a high flow k&n filter that i just cleaned. ive gone through all the basics and still hasnt fixed it every professionnal mechanic around here cant figure it out.

Matt,
Wow, this even gets more interesting! Some more questions then. When you say it goes "back to idle" does it feel like more of a loss of power? ie: lack of fuel or spark? At any time do you loose any dash or other electrical items?

I really wish I could view some of the scan data from those other techs! Any chance they would be willing to share info/email w/ me? Let me know!

Chris

[quote:51f934ac45="carundell"]Matt,
Wow, this even gets more interesting! Some more questions then. When you say it goes "back to idle" does it feel like more of a loss of power? ie: lack of fuel or spark? At any time do you loose any dash or other electrical items?

I really wish I could view some of the scan data from those other techs! Any chance they would be willing to share info/email w/ me? Let me know!

Chris[/quote:51f934ac45]

Hey Chris
the one mechanic that did almost all the work was the head mechanic at firestone here but transferred to georgia so there no chance and the other mechanic i use doesnt have a scan tool however even the dealer told me they had no clue what was going on with it. when it drops to idle its like there no power but the second u push the gas far enough down the rpms jump up most of the time smoothly but sometimes theres like 3 clunks coming from the front of the tranny or the back of the motor any chance those clunks could be bad motor mounts? and could a bad idle air controler cause the whole problem? been doing lots of research and so far the only thing i was able to come up with was either the pcm or iac sensor however what doesnt make sense with the iac is the fact that it revs up like normal and settles back to 800 rpms after starting. the tranny was rebuilt 2 years ago. had the internal gas fuel filter replaced is there another fuel filteron these vehicles i may have missed?

[quote:52f8576569="fireball2889"][quote:52f8576569="carundell"]Matt,
Wow, this even gets more interesting! Some more questions then. When you say it goes "back to idle" does it feel like more of a loss of power? ie: lack of fuel or spark? At any time do you loose any dash or other electrical items?

I really wish I could view some of the scan data from those other techs! Any chance they would be willing to share info/email w/ me? Let me know!

Chris[/quote:52f8576569]

Hey Chris
the one mechanic that did almost all the work was the head mechanic at firestone here but transferred to georgia so there no chance and the other mechanic i use doesnt have a scan tool however even the dealer told me they had no clue what was going on with it. when it drops to idle its like there no power but the second u push the gas far enough down the rpms jump up most of the time smoothly but sometimes theres like 3 clunks coming from the front of the tranny or the back of the motor any chance those clunks could be bad motor mounts? and could a bad idle air controler cause the whole problem? been doing lots of research and so far the only thing i was able to come up with was either the pcm or iac sensor however what doesnt make sense with the iac is the fact that it revs up like normal and settles back to 800 rpms after starting. the tranny was rebuilt 2 years ago. had the internal gas fuel filter replaced is there another fuel filteron these vehicles i may have missed?[/quote:52f8576569]

Hey Matt,
Yeah we can pretty much rule out the IAC as it has no effect on the throttle when your driving. Did the dealer also scan it when it was there?

Give me a day for some research and I'll get back to ya!

Chris

[quote:2becef234e="carundell"][quote:2becef234e="fireball2889"][quote:2becef234e="carundell"]Matt,
Wow, this even gets more interesting! Some more questions then. When you say it goes "back to idle" does it feel like more of a loss of power? ie: lack of fuel or spark? At any time do you loose any dash or other electrical items?

I really wish I could view some of the scan data from those other techs! Any chance they would be willing to share info/email w/ me? Let me know!

Chris[/quote:2becef234e]

Hey Chris
the one mechanic that did almost all the work was the head mechanic at firestone here but transferred to georgia so there no chance and the other mechanic i use doesnt have a scan tool however even the dealer told me they had no clue what was going on with it. when it drops to idle its like there no power but the second u push the gas far enough down the rpms jump up most of the time smoothly but sometimes theres like 3 clunks coming from the front of the tranny or the back of the motor any chance those clunks could be bad motor mounts? and could a bad idle air controler cause the whole problem? been doing lots of research and so far the only thing i was able to come up with was either the pcm or iac sensor however what doesnt make sense with the iac is the fact that it revs up like normal and settles back to 800 rpms after starting. the tranny was rebuilt 2 years ago. had the internal gas fuel filter replaced is there another fuel filteron these vehicles i may have missed?[/quote:2becef234e]

Hey Matt,
Yeah we can pretty much rule out the IAC as it has no effect on the throttle when your driving. Did the dealer also scan it when it was there?

Give me a day for some research and I'll get back to ya!

Chris[/quote:2becef234e]

Chris
they never scanned it i never asked them to not for $60 when they werent even sure they would be able to pick anything up because there was no check engine light however i think it has to do with the fuel or air mixture. it acts like its surging could it be a fuel pump going out or the tranny messing up