Re: Lost top end power in 88 Cherokee 4.0.
 

Plug wires can do this, but they will usually give you some backfiring along
with the bogging down.

Earle

"Mike Romain" <romainm@sympatico.ca> wrote in message
news:4659a194$0$3020$9a6e19ea@unlimited.newshostin g.com...
> Ok, I am on a fishing expedition for likely things to check.
>
> Our 88 Cherokee with the 4.0 has lost power above half throttle. It
> goes fine up to that point, then just bogs, no matter what gear it is
> in. It has been neglected for 4 years as far as tuning goes due to me
> not being up to it.
>
> I first changed out the 'very' dirty distributor cap and rotor which
> made starting 'much' faster and smoother.
>
> I then changed the gas filter because it was once again rusted to the
> rot point after about 8 years.
>
> Air filter is new.
>
> I cleaned the connections on the TPS and IAC and verified the TPS
> doesn't have any 'dead' spots with my meter.
>
> I cleaned the CPS and coil connections also.
>
> No joy on any of that.
>
> I have been having some cold idle issues and have been thinking on
> cleaning the IAC, but don't know if that will have a top end effect or
not.
>
> I am also thinking on unplugging the EGR just to make sure it isn't
> blown vacuum wise because it only bogs under throttle when things like
> the EGR are active.
>
> Any other ideas?
>
> Mike
> 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> 88 Cherokee 235 BFG AT's
> Canadian Off Road Trips Photos: Non members can still view!
> Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
> (More Off Road album links at bottom of the view page)

Re: Lost top end power in 88 Cherokee 4.0.
 

Plug wires can do this, but they will usually give you some backfiring along
with the bogging down.

Earle

"Mike Romain" <romainm@sympatico.ca> wrote in message
news:4659a194$0$3020$9a6e19ea@unlimited.newshostin g.com...
> Ok, I am on a fishing expedition for likely things to check.
>
> Our 88 Cherokee with the 4.0 has lost power above half throttle. It
> goes fine up to that point, then just bogs, no matter what gear it is
> in. It has been neglected for 4 years as far as tuning goes due to me
> not being up to it.
>
> I first changed out the 'very' dirty distributor cap and rotor which
> made starting 'much' faster and smoother.
>
> I then changed the gas filter because it was once again rusted to the
> rot point after about 8 years.
>
> Air filter is new.
>
> I cleaned the connections on the TPS and IAC and verified the TPS
> doesn't have any 'dead' spots with my meter.
>
> I cleaned the CPS and coil connections also.
>
> No joy on any of that.
>
> I have been having some cold idle issues and have been thinking on
> cleaning the IAC, but don't know if that will have a top end effect or
not.
>
> I am also thinking on unplugging the EGR just to make sure it isn't
> blown vacuum wise because it only bogs under throttle when things like
> the EGR are active.
>
> Any other ideas?
>
> Mike
> 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> 88 Cherokee 235 BFG AT's
> Canadian Off Road Trips Photos: Non members can still view!
> Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
> (More Off Road album links at bottom of the view page)

Re: Lost top end power in 88 Cherokee 4.0.
 

Plug wires can do this, but they will usually give you some backfiring along
with the bogging down.

Earle

"Mike Romain" <romainm@sympatico.ca> wrote in message
news:4659a194$0$3020$9a6e19ea@unlimited.newshostin g.com...
> Ok, I am on a fishing expedition for likely things to check.
>
> Our 88 Cherokee with the 4.0 has lost power above half throttle. It
> goes fine up to that point, then just bogs, no matter what gear it is
> in. It has been neglected for 4 years as far as tuning goes due to me
> not being up to it.
>
> I first changed out the 'very' dirty distributor cap and rotor which
> made starting 'much' faster and smoother.
>
> I then changed the gas filter because it was once again rusted to the
> rot point after about 8 years.
>
> Air filter is new.
>
> I cleaned the connections on the TPS and IAC and verified the TPS
> doesn't have any 'dead' spots with my meter.
>
> I cleaned the CPS and coil connections also.
>
> No joy on any of that.
>
> I have been having some cold idle issues and have been thinking on
> cleaning the IAC, but don't know if that will have a top end effect or
not.
>
> I am also thinking on unplugging the EGR just to make sure it isn't
> blown vacuum wise because it only bogs under throttle when things like
> the EGR are active.
>
> Any other ideas?
>
> Mike
> 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> 88 Cherokee 235 BFG AT's
> Canadian Off Road Trips Photos: Non members can still view!
> Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
> (More Off Road album links at bottom of the view page)

Re: Lost top end power in 88 Cherokee 4.0.
 

Mike Romain <romainm@sympatico.ca> wrote:

> Ok, I am on a fishing expedition for likely things to check.
>
> Our 88 Cherokee with the 4.0 has lost power above half throttle.
> It goes fine up to that point, then just bogs, no matter what gear
> it is in. It has been neglected for 4 years as far as tuning goes
> due to me not being up to it.
>
> I first changed out the 'very' dirty distributor cap and rotor
> which made starting 'much' faster and smoother.
>
> I then changed the gas filter because it was once again rusted to
> the rot point after about 8 years.
>
> Air filter is new.
>
> I cleaned the connections on the TPS and IAC and verified the TPS
> doesn't have any 'dead' spots with my meter.
>
> I cleaned the CPS and coil connections also.
>
> No joy on any of that.
>
> I have been having some cold idle issues and have been thinking on
> cleaning the IAC, but don't know if that will have a top end
> effect or not.
>
> I am also thinking on unplugging the EGR just to make sure it
> isn't blown vacuum wise because it only bogs under throttle when
> things like the EGR are active.
>
> Any other ideas?

Look at simple things, it sounds like it might be starving for fuel?
Test fuel pressure and flow, consider clogged catalytic converter, look
for a stopped up fuel vent. You changed the fuel filter, is there
possibly another one, maybe in the tank?





--
XS11E, Killing all posts from Google Groups
The Usenet Improvement Project: http://blinkynet.net/comp/uip5.html

Re: Lost top end power in 88 Cherokee 4.0.
 

Mike Romain <romainm@sympatico.ca> wrote:

> Ok, I am on a fishing expedition for likely things to check.
>
> Our 88 Cherokee with the 4.0 has lost power above half throttle.
> It goes fine up to that point, then just bogs, no matter what gear
> it is in. It has been neglected for 4 years as far as tuning goes
> due to me not being up to it.
>
> I first changed out the 'very' dirty distributor cap and rotor
> which made starting 'much' faster and smoother.
>
> I then changed the gas filter because it was once again rusted to
> the rot point after about 8 years.
>
> Air filter is new.
>
> I cleaned the connections on the TPS and IAC and verified the TPS
> doesn't have any 'dead' spots with my meter.
>
> I cleaned the CPS and coil connections also.
>
> No joy on any of that.
>
> I have been having some cold idle issues and have been thinking on
> cleaning the IAC, but don't know if that will have a top end
> effect or not.
>
> I am also thinking on unplugging the EGR just to make sure it
> isn't blown vacuum wise because it only bogs under throttle when
> things like the EGR are active.
>
> Any other ideas?

Look at simple things, it sounds like it might be starving for fuel?
Test fuel pressure and flow, consider clogged catalytic converter, look
for a stopped up fuel vent. You changed the fuel filter, is there
possibly another one, maybe in the tank?





--
XS11E, Killing all posts from Google Groups
The Usenet Improvement Project: http://blinkynet.net/comp/uip5.html

Re: Lost top end power in 88 Cherokee 4.0.
 

Mike Romain <romainm@sympatico.ca> wrote:

> Ok, I am on a fishing expedition for likely things to check.
>
> Our 88 Cherokee with the 4.0 has lost power above half throttle.
> It goes fine up to that point, then just bogs, no matter what gear
> it is in. It has been neglected for 4 years as far as tuning goes
> due to me not being up to it.
>
> I first changed out the 'very' dirty distributor cap and rotor
> which made starting 'much' faster and smoother.
>
> I then changed the gas filter because it was once again rusted to
> the rot point after about 8 years.
>
> Air filter is new.
>
> I cleaned the connections on the TPS and IAC and verified the TPS
> doesn't have any 'dead' spots with my meter.
>
> I cleaned the CPS and coil connections also.
>
> No joy on any of that.
>
> I have been having some cold idle issues and have been thinking on
> cleaning the IAC, but don't know if that will have a top end
> effect or not.
>
> I am also thinking on unplugging the EGR just to make sure it
> isn't blown vacuum wise because it only bogs under throttle when
> things like the EGR are active.
>
> Any other ideas?

Look at simple things, it sounds like it might be starving for fuel?
Test fuel pressure and flow, consider clogged catalytic converter, look
for a stopped up fuel vent. You changed the fuel filter, is there
possibly another one, maybe in the tank?





--
XS11E, Killing all posts from Google Groups
The Usenet Improvement Project: http://blinkynet.net/comp/uip5.html

Re: Lost top end power in 88 Cherokee 4.0.
 

Mike Romain <romainm@sympatico.ca> wrote:

> Ok, I am on a fishing expedition for likely things to check.
>
> Our 88 Cherokee with the 4.0 has lost power above half throttle.
> It goes fine up to that point, then just bogs, no matter what gear
> it is in. It has been neglected for 4 years as far as tuning goes
> due to me not being up to it.
>
> I first changed out the 'very' dirty distributor cap and rotor
> which made starting 'much' faster and smoother.
>
> I then changed the gas filter because it was once again rusted to
> the rot point after about 8 years.
>
> Air filter is new.
>
> I cleaned the connections on the TPS and IAC and verified the TPS
> doesn't have any 'dead' spots with my meter.
>
> I cleaned the CPS and coil connections also.
>
> No joy on any of that.
>
> I have been having some cold idle issues and have been thinking on
> cleaning the IAC, but don't know if that will have a top end
> effect or not.
>
> I am also thinking on unplugging the EGR just to make sure it
> isn't blown vacuum wise because it only bogs under throttle when
> things like the EGR are active.
>
> Any other ideas?

Look at simple things, it sounds like it might be starving for fuel?
Test fuel pressure and flow, consider clogged catalytic converter, look
for a stopped up fuel vent. You changed the fuel filter, is there
possibly another one, maybe in the tank?





--
XS11E, Killing all posts from Google Groups
The Usenet Improvement Project: http://blinkynet.net/comp/uip5.html

Re: Lost top end power in 88 Cherokee 4.0.
 

On May 27, 11:20 am, Mike Romain <roma...@sympatico.ca> wrote:
> Ok, I am on a fishing expedition for likely things to check.
>
> Our 88 Cherokee with the 4.0 has lost power above half throttle. It
> goes fine up to that point, then just bogs, no matter what gear it is
> in. It has been neglected for 4 years as far as tuning goes due to me
> not being up to it.
>
> I first changed out the 'very' dirty distributor cap and rotor which
> made starting 'much' faster and smoother.
>
> I then changed the gas filter because it was once again rusted to the
> rot point after about 8 years.
>
> Air filter is new.
>
> I cleaned the connections on the TPS and IAC and verified the TPS
> doesn't have any 'dead' spots with my meter.
>
> I cleaned the CPS and coil connections also.
>
> No joy on any of that.
>
> I have been having some cold idle issues and have been thinking on
> cleaning the IAC, but don't know if that will have a top end effect or not.
>
> I am also thinking on unplugging the EGR just to make sure it isn't
> blown vacuum wise because it only bogs under throttle when things like
> the EGR are active.
>
> Any other ideas?
>
> Mike
> 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> 88 Cherokee 235 BFG AT's
> Canadian Off Road Trips Photos: Non members can still view!
> Jan/06http://www.imagestation.com/album/pictures.html?id=2115147590
> (More Off Road album links at bottom of the view page)

What does exactly "then just bogs" mean? The Jeep does not go any
faster, or it stalls and stops? What precise noises/knocks and
symptoms, etc?

On idle, what happens if you press accelerator until above half
throttle? Is there a loss of power?

If the fuel pressure is low, the engine can run fine upto a point,
until the demand for fuel exceeds the supply due to low pressure.

Re: Lost top end power in 88 Cherokee 4.0.
 

On May 27, 11:20 am, Mike Romain <roma...@sympatico.ca> wrote:
> Ok, I am on a fishing expedition for likely things to check.
>
> Our 88 Cherokee with the 4.0 has lost power above half throttle. It
> goes fine up to that point, then just bogs, no matter what gear it is
> in. It has been neglected for 4 years as far as tuning goes due to me
> not being up to it.
>
> I first changed out the 'very' dirty distributor cap and rotor which
> made starting 'much' faster and smoother.
>
> I then changed the gas filter because it was once again rusted to the
> rot point after about 8 years.
>
> Air filter is new.
>
> I cleaned the connections on the TPS and IAC and verified the TPS
> doesn't have any 'dead' spots with my meter.
>
> I cleaned the CPS and coil connections also.
>
> No joy on any of that.
>
> I have been having some cold idle issues and have been thinking on
> cleaning the IAC, but don't know if that will have a top end effect or not.
>
> I am also thinking on unplugging the EGR just to make sure it isn't
> blown vacuum wise because it only bogs under throttle when things like
> the EGR are active.
>
> Any other ideas?
>
> Mike
> 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> 88 Cherokee 235 BFG AT's
> Canadian Off Road Trips Photos: Non members can still view!
> Jan/06http://www.imagestation.com/album/pictures.html?id=2115147590
> (More Off Road album links at bottom of the view page)

What does exactly "then just bogs" mean? The Jeep does not go any
faster, or it stalls and stops? What precise noises/knocks and
symptoms, etc?

On idle, what happens if you press accelerator until above half
throttle? Is there a loss of power?

If the fuel pressure is low, the engine can run fine upto a point,
until the demand for fuel exceeds the supply due to low pressure.

Re: Lost top end power in 88 Cherokee 4.0.
 

On May 27, 11:20 am, Mike Romain <roma...@sympatico.ca> wrote:
> Ok, I am on a fishing expedition for likely things to check.
>
> Our 88 Cherokee with the 4.0 has lost power above half throttle. It
> goes fine up to that point, then just bogs, no matter what gear it is
> in. It has been neglected for 4 years as far as tuning goes due to me
> not being up to it.
>
> I first changed out the 'very' dirty distributor cap and rotor which
> made starting 'much' faster and smoother.
>
> I then changed the gas filter because it was once again rusted to the
> rot point after about 8 years.
>
> Air filter is new.
>
> I cleaned the connections on the TPS and IAC and verified the TPS
> doesn't have any 'dead' spots with my meter.
>
> I cleaned the CPS and coil connections also.
>
> No joy on any of that.
>
> I have been having some cold idle issues and have been thinking on
> cleaning the IAC, but don't know if that will have a top end effect or not.
>
> I am also thinking on unplugging the EGR just to make sure it isn't
> blown vacuum wise because it only bogs under throttle when things like
> the EGR are active.
>
> Any other ideas?
>
> Mike
> 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> 88 Cherokee 235 BFG AT's
> Canadian Off Road Trips Photos: Non members can still view!
> Jan/06http://www.imagestation.com/album/pictures.html?id=2115147590
> (More Off Road album links at bottom of the view page)

What does exactly "then just bogs" mean? The Jeep does not go any
faster, or it stalls and stops? What precise noises/knocks and
symptoms, etc?

On idle, what happens if you press accelerator until above half
throttle? Is there a loss of power?

If the fuel pressure is low, the engine can run fine upto a point,
until the demand for fuel exceeds the supply due to low pressure.