Re: New Cam, Jeep will only run without TPS
 

I have tried setting the dist in several tooth positions. I've had no
success with, it runs the same regardless if I advance or retard the
crankshaft or the dist. I set the dist the way the mopar performance
Jeep engine guide and the chiltons manual both told me. It runs great
below 1800 RPM, purs like a kitten, but 1800+, it front and backfires
sometimes. From what I understand, the PCM advances and retards the
timing and the fuel.

philthy wrote:
> you have to set the timing gears bac to straight up and then you have to
> properly resync the dist(.need factory manual for procedure) and get the dist
> rotor past #1 cylinder tower of the dist.cap to get it in the correct place
> even if it means spinning oil pump drive a hair and it should drop in
>
> "L.W.(Bill) ------ III" wrote:
>
> > I am a total loss as to how it would run without the Crankshaft
> > Position Sensor. It should default into the safe mode, with no spark
> > advance. Maybe you have your distributor installed in such a way so that
> > it's Cam Position Sensor somehow takes over??????? What's the timing
> > light show, initial and total?
> > God Bless America, Bill O|||||||O
> > mailto:-------------------- http://www.----------.com/
> >
> > jeepinacreek wrote:
> > >
> > > I recently put a new cam in my 1997 Jeep Wrangler 4.0L. I figured it
> > > was a great mod with out totaly stroking the motor. After completing
> > > the buildup and starting it for the first time, I thought great it
> > > runs. Then I ran up and it starting backfiring at around 1800+ RPM.
> > > This has been my battle for the last three months.
> > >
> > > A little about my Jeep;
> > > Doug thorley header
> > > bored out 62mm throttle
> > > MSD ignition
> > > New catalatic convertor, Flowmaster 50 exhaust Cold air intake 4in
> > > Curry Enterpise lift 33in tires, 4:10 gears, lockers
> > >
> > > What I have done to fix this so far;
> > > -Took it the dealer, they wouldn't touch it.
> > > -I currently have timing chain retarded -5 degree's due to pinging, cut
> > > down on backfiring.
> > > -I also had it advanced +5 degree's, caused a lot more backfiring.
> > > -I also ran the cam at TDC with no advance or timing. This is the
> > > original way I built it.
> > > -Changed TPS
> > > -Changed spark plugs, wires, cap, rotor, and coil. Currently run MSD
> > > ignition which I disconnected and the Jeep barely ran. Connected it
> > > back up and seems to be the only thing keeping it running. So I know
> > > the MSD works -changed O2 sensors -changed fuel pump and filters in
> > > tank, gas cap to.
> > > -Changed fuel injecters to 21LB injectors, stock is around 23.5LB -Put
> > > an air/fuel ratio gauge on it.
> > >
> > > So my latest attempt to get this thing running right truely has me
> > > scratching my head, I left the TPS wire connected disconnected, drove
> > > it and it runs fine. No backfire at 1800+ RPM, it doesn't surge,
> > > hesitate or ping or miss or run rich. It runs great, I can drive it on
> > > the freeway now.
> > >
> > > I am on my last leg with this thing. Anyone have any ideas or
> > > suggestions?????? Please help or i may put the stock cam back in.

Re: New Cam, Jeep will only run without TPS
 

I live in Albuquerque, NM. Why??
philthy wrote:
> are u in michigan by any chance???
>
> "L.W.(Bill) ------ III" wrote:
>
> > I am a total loss as to how it would run without the Crankshaft
> > Position Sensor. It should default into the safe mode, with no spark
> > advance. Maybe you have your distributor installed in such a way so that
> > it's Cam Position Sensor somehow takes over??????? What's the timing
> > light show, initial and total?
> > God Bless America, Bill O|||||||O
> > mailto:-------------------- http://www.----------.com/
> >
> > jeepinacreek wrote:
> > >
> > > I recently put a new cam in my 1997 Jeep Wrangler 4.0L. I figured it
> > > was a great mod with out totaly stroking the motor. After completing
> > > the buildup and starting it for the first time, I thought great it
> > > runs. Then I ran up and it starting backfiring at around 1800+ RPM.
> > > This has been my battle for the last three months.
> > >
> > > A little about my Jeep;
> > > Doug thorley header
> > > bored out 62mm throttle
> > > MSD ignition
> > > New catalatic convertor, Flowmaster 50 exhaust Cold air intake 4in
> > > Curry Enterpise lift 33in tires, 4:10 gears, lockers
> > >
> > > What I have done to fix this so far;
> > > -Took it the dealer, they wouldn't touch it.
> > > -I currently have timing chain retarded -5 degree's due to pinging, cut
> > > down on backfiring.
> > > -I also had it advanced +5 degree's, caused a lot more backfiring.
> > > -I also ran the cam at TDC with no advance or timing. This is the
> > > original way I built it.
> > > -Changed TPS
> > > -Changed spark plugs, wires, cap, rotor, and coil. Currently run MSD
> > > ignition which I disconnected and the Jeep barely ran. Connected it
> > > back up and seems to be the only thing keeping it running. So I know
> > > the MSD works -changed O2 sensors -changed fuel pump and filters in
> > > tank, gas cap to.
> > > -Changed fuel injecters to 21LB injectors, stock is around 23.5LB -Put
> > > an air/fuel ratio gauge on it.
> > >
> > > So my latest attempt to get this thing running right truely has me
> > > scratching my head, I left the TPS wire connected disconnected, drove
> > > it and it runs fine. No backfire at 1800+ RPM, it doesn't surge,
> > > hesitate or ping or miss or run rich. It runs great, I can drive it on
> > > the freeway now.
> > >
> > > I am on my last leg with this thing. Anyone have any ideas or
> > > suggestions?????? Please help or i may put the stock cam back in.

Re: New Cam, Jeep will only run without TPS
 

I live in Albuquerque, NM. Why??
philthy wrote:
> are u in michigan by any chance???
>
> "L.W.(Bill) ------ III" wrote:
>
> > I am a total loss as to how it would run without the Crankshaft
> > Position Sensor. It should default into the safe mode, with no spark
> > advance. Maybe you have your distributor installed in such a way so that
> > it's Cam Position Sensor somehow takes over??????? What's the timing
> > light show, initial and total?
> > God Bless America, Bill O|||||||O
> > mailto:-------------------- http://www.----------.com/
> >
> > jeepinacreek wrote:
> > >
> > > I recently put a new cam in my 1997 Jeep Wrangler 4.0L. I figured it
> > > was a great mod with out totaly stroking the motor. After completing
> > > the buildup and starting it for the first time, I thought great it
> > > runs. Then I ran up and it starting backfiring at around 1800+ RPM.
> > > This has been my battle for the last three months.
> > >
> > > A little about my Jeep;
> > > Doug thorley header
> > > bored out 62mm throttle
> > > MSD ignition
> > > New catalatic convertor, Flowmaster 50 exhaust Cold air intake 4in
> > > Curry Enterpise lift 33in tires, 4:10 gears, lockers
> > >
> > > What I have done to fix this so far;
> > > -Took it the dealer, they wouldn't touch it.
> > > -I currently have timing chain retarded -5 degree's due to pinging, cut
> > > down on backfiring.
> > > -I also had it advanced +5 degree's, caused a lot more backfiring.
> > > -I also ran the cam at TDC with no advance or timing. This is the
> > > original way I built it.
> > > -Changed TPS
> > > -Changed spark plugs, wires, cap, rotor, and coil. Currently run MSD
> > > ignition which I disconnected and the Jeep barely ran. Connected it
> > > back up and seems to be the only thing keeping it running. So I know
> > > the MSD works -changed O2 sensors -changed fuel pump and filters in
> > > tank, gas cap to.
> > > -Changed fuel injecters to 21LB injectors, stock is around 23.5LB -Put
> > > an air/fuel ratio gauge on it.
> > >
> > > So my latest attempt to get this thing running right truely has me
> > > scratching my head, I left the TPS wire connected disconnected, drove
> > > it and it runs fine. No backfire at 1800+ RPM, it doesn't surge,
> > > hesitate or ping or miss or run rich. It runs great, I can drive it on
> > > the freeway now.
> > >
> > > I am on my last leg with this thing. Anyone have any ideas or
> > > suggestions?????? Please help or i may put the stock cam back in.

Re: New Cam, Jeep will only run without TPS
 

I live in Albuquerque, NM. Why??
philthy wrote:
> are u in michigan by any chance???
>
> "L.W.(Bill) ------ III" wrote:
>
> > I am a total loss as to how it would run without the Crankshaft
> > Position Sensor. It should default into the safe mode, with no spark
> > advance. Maybe you have your distributor installed in such a way so that
> > it's Cam Position Sensor somehow takes over??????? What's the timing
> > light show, initial and total?
> > God Bless America, Bill O|||||||O
> > mailto:-------------------- http://www.----------.com/
> >
> > jeepinacreek wrote:
> > >
> > > I recently put a new cam in my 1997 Jeep Wrangler 4.0L. I figured it
> > > was a great mod with out totaly stroking the motor. After completing
> > > the buildup and starting it for the first time, I thought great it
> > > runs. Then I ran up and it starting backfiring at around 1800+ RPM.
> > > This has been my battle for the last three months.
> > >
> > > A little about my Jeep;
> > > Doug thorley header
> > > bored out 62mm throttle
> > > MSD ignition
> > > New catalatic convertor, Flowmaster 50 exhaust Cold air intake 4in
> > > Curry Enterpise lift 33in tires, 4:10 gears, lockers
> > >
> > > What I have done to fix this so far;
> > > -Took it the dealer, they wouldn't touch it.
> > > -I currently have timing chain retarded -5 degree's due to pinging, cut
> > > down on backfiring.
> > > -I also had it advanced +5 degree's, caused a lot more backfiring.
> > > -I also ran the cam at TDC with no advance or timing. This is the
> > > original way I built it.
> > > -Changed TPS
> > > -Changed spark plugs, wires, cap, rotor, and coil. Currently run MSD
> > > ignition which I disconnected and the Jeep barely ran. Connected it
> > > back up and seems to be the only thing keeping it running. So I know
> > > the MSD works -changed O2 sensors -changed fuel pump and filters in
> > > tank, gas cap to.
> > > -Changed fuel injecters to 21LB injectors, stock is around 23.5LB -Put
> > > an air/fuel ratio gauge on it.
> > >
> > > So my latest attempt to get this thing running right truely has me
> > > scratching my head, I left the TPS wire connected disconnected, drove
> > > it and it runs fine. No backfire at 1800+ RPM, it doesn't surge,
> > > hesitate or ping or miss or run rich. It runs great, I can drive it on
> > > the freeway now.
> > >
> > > I am on my last leg with this thing. Anyone have any ideas or
> > > suggestions?????? Please help or i may put the stock cam back in.

Re: New Cam, Jeep will only run without TPS
 

I tried you idea of reseting the PCM and turning the key and not
starting and turning the throttle body. Didn't work. This time the was
a lot of backfiring at very low RPM's and front firing at high RPMS?
Any suggestions?

DougW wrote:
> Jeffrey DeWitt wrote:
> > Wonder how the engine runs with the WOT signal on all the time?
> >
> > The OP said the sensor was replaced, but maybe the new one was bad or
> > wrong? Is it possible to connect the sensor wrong?
>
> At least on the ZJ it's possible. :) The shaft and tangs have to be
> lined up. Thing is, if they arn't the throttle simply won't open.
> (or at least that's how the ZJ acts) Some vehicles require the TPS
> to be indexed by watching the voltage.
>
> In all cases it's a good idea to reset the computer and reprogram the
> range. Simply pull the battery off (or pull the fuses), have lunch,
> put the battery back on. turn the key to on, (engine not running)
> and slowly move the throttle between closed and wide open about
> five or six times. Holding it at the limits for a few seconds.
> Then turn the key off, start the car, and let it idle, drive it
> normally, and eventually hit the highway.
>
>
> Easy enough to test the TPS sensor. Just takes a volt meter.
> (backprobe. i.e. don't pierce the wires, just slide a pin/paperclip
> up the back of the connector)
>
> with ignition on, engine not running.
> Measure across the two outer wires. Should have 5 volts.
> Measure between the ground wire and the center wire.
> Throttle closed >200 milliVolts
> Throttle wide open <4.8 Volts
> As the throttle is moved between idle and WOT, the voltage
> should smootly increase with no dropouts or jumps.
>
> --
> DougW

Re: New Cam, Jeep will only run without TPS
 

I tried you idea of reseting the PCM and turning the key and not
starting and turning the throttle body. Didn't work. This time the was
a lot of backfiring at very low RPM's and front firing at high RPMS?
Any suggestions?

DougW wrote:
> Jeffrey DeWitt wrote:
> > Wonder how the engine runs with the WOT signal on all the time?
> >
> > The OP said the sensor was replaced, but maybe the new one was bad or
> > wrong? Is it possible to connect the sensor wrong?
>
> At least on the ZJ it's possible. :) The shaft and tangs have to be
> lined up. Thing is, if they arn't the throttle simply won't open.
> (or at least that's how the ZJ acts) Some vehicles require the TPS
> to be indexed by watching the voltage.
>
> In all cases it's a good idea to reset the computer and reprogram the
> range. Simply pull the battery off (or pull the fuses), have lunch,
> put the battery back on. turn the key to on, (engine not running)
> and slowly move the throttle between closed and wide open about
> five or six times. Holding it at the limits for a few seconds.
> Then turn the key off, start the car, and let it idle, drive it
> normally, and eventually hit the highway.
>
>
> Easy enough to test the TPS sensor. Just takes a volt meter.
> (backprobe. i.e. don't pierce the wires, just slide a pin/paperclip
> up the back of the connector)
>
> with ignition on, engine not running.
> Measure across the two outer wires. Should have 5 volts.
> Measure between the ground wire and the center wire.
> Throttle closed >200 milliVolts
> Throttle wide open <4.8 Volts
> As the throttle is moved between idle and WOT, the voltage
> should smootly increase with no dropouts or jumps.
>
> --
> DougW

Re: New Cam, Jeep will only run without TPS
 

I tried you idea of reseting the PCM and turning the key and not
starting and turning the throttle body. Didn't work. This time the was
a lot of backfiring at very low RPM's and front firing at high RPMS?
Any suggestions?

DougW wrote:
> Jeffrey DeWitt wrote:
> > Wonder how the engine runs with the WOT signal on all the time?
> >
> > The OP said the sensor was replaced, but maybe the new one was bad or
> > wrong? Is it possible to connect the sensor wrong?
>
> At least on the ZJ it's possible. :) The shaft and tangs have to be
> lined up. Thing is, if they arn't the throttle simply won't open.
> (or at least that's how the ZJ acts) Some vehicles require the TPS
> to be indexed by watching the voltage.
>
> In all cases it's a good idea to reset the computer and reprogram the
> range. Simply pull the battery off (or pull the fuses), have lunch,
> put the battery back on. turn the key to on, (engine not running)
> and slowly move the throttle between closed and wide open about
> five or six times. Holding it at the limits for a few seconds.
> Then turn the key off, start the car, and let it idle, drive it
> normally, and eventually hit the highway.
>
>
> Easy enough to test the TPS sensor. Just takes a volt meter.
> (backprobe. i.e. don't pierce the wires, just slide a pin/paperclip
> up the back of the connector)
>
> with ignition on, engine not running.
> Measure across the two outer wires. Should have 5 volts.
> Measure between the ground wire and the center wire.
> Throttle closed >200 milliVolts
> Throttle wide open <4.8 Volts
> As the throttle is moved between idle and WOT, the voltage
> should smootly increase with no dropouts or jumps.
>
> --
> DougW

Re: New Cam, Jeep will only run without TPS
 

I haven't put the timing gear back to TDC on the timing marks. Its suck
a pain in the ass with the motor installed and 16 bucks for a gasket.
I've done it three times now, the little things have been adding up for
a while. Anyway, I tried to put the dist past the no.1 post. It has
always lined up on the post or to far ahead of the post and doesn't
start or runs real rough.

philthy wrote:
> you have to set the timing gears bac to straight up and then you have to
> properly resync the dist(.need factory manual for procedure) and get the dist
> rotor past #1 cylinder tower of the dist.cap to get it in the correct place
> even if it means spinning oil pump drive a hair and it should drop in
>
> "L.W.(Bill) ------ III" wrote:
>
> > I am a total loss as to how it would run without the Crankshaft
> > Position Sensor. It should default into the safe mode, with no spark
> > advance. Maybe you have your distributor installed in such a way so that
> > it's Cam Position Sensor somehow takes over??????? What's the timing
> > light show, initial and total?
> > God Bless America, Bill O|||||||O
> > mailto:-------------------- http://www.----------.com/
> >
> > jeepinacreek wrote:
> > >
> > > I recently put a new cam in my 1997 Jeep Wrangler 4.0L. I figured it
> > > was a great mod with out totaly stroking the motor. After completing
> > > the buildup and starting it for the first time, I thought great it
> > > runs. Then I ran up and it starting backfiring at around 1800+ RPM.
> > > This has been my battle for the last three months.
> > >
> > > A little about my Jeep;
> > > Doug thorley header
> > > bored out 62mm throttle
> > > MSD ignition
> > > New catalatic convertor, Flowmaster 50 exhaust Cold air intake 4in
> > > Curry Enterpise lift 33in tires, 4:10 gears, lockers
> > >
> > > What I have done to fix this so far;
> > > -Took it the dealer, they wouldn't touch it.
> > > -I currently have timing chain retarded -5 degree's due to pinging, cut
> > > down on backfiring.
> > > -I also had it advanced +5 degree's, caused a lot more backfiring.
> > > -I also ran the cam at TDC with no advance or timing. This is the
> > > original way I built it.
> > > -Changed TPS
> > > -Changed spark plugs, wires, cap, rotor, and coil. Currently run MSD
> > > ignition which I disconnected and the Jeep barely ran. Connected it
> > > back up and seems to be the only thing keeping it running. So I know
> > > the MSD works -changed O2 sensors -changed fuel pump and filters in
> > > tank, gas cap to.
> > > -Changed fuel injecters to 21LB injectors, stock is around 23.5LB -Put
> > > an air/fuel ratio gauge on it.
> > >
> > > So my latest attempt to get this thing running right truely has me
> > > scratching my head, I left the TPS wire connected disconnected, drove
> > > it and it runs fine. No backfire at 1800+ RPM, it doesn't surge,
> > > hesitate or ping or miss or run rich. It runs great, I can drive it on
> > > the freeway now.
> > >
> > > I am on my last leg with this thing. Anyone have any ideas or
> > > suggestions?????? Please help or i may put the stock cam back in.

Re: New Cam, Jeep will only run without TPS
 

I haven't put the timing gear back to TDC on the timing marks. Its suck
a pain in the ass with the motor installed and 16 bucks for a gasket.
I've done it three times now, the little things have been adding up for
a while. Anyway, I tried to put the dist past the no.1 post. It has
always lined up on the post or to far ahead of the post and doesn't
start or runs real rough.

philthy wrote:
> you have to set the timing gears bac to straight up and then you have to
> properly resync the dist(.need factory manual for procedure) and get the dist
> rotor past #1 cylinder tower of the dist.cap to get it in the correct place
> even if it means spinning oil pump drive a hair and it should drop in
>
> "L.W.(Bill) ------ III" wrote:
>
> > I am a total loss as to how it would run without the Crankshaft
> > Position Sensor. It should default into the safe mode, with no spark
> > advance. Maybe you have your distributor installed in such a way so that
> > it's Cam Position Sensor somehow takes over??????? What's the timing
> > light show, initial and total?
> > God Bless America, Bill O|||||||O
> > mailto:-------------------- http://www.----------.com/
> >
> > jeepinacreek wrote:
> > >
> > > I recently put a new cam in my 1997 Jeep Wrangler 4.0L. I figured it
> > > was a great mod with out totaly stroking the motor. After completing
> > > the buildup and starting it for the first time, I thought great it
> > > runs. Then I ran up and it starting backfiring at around 1800+ RPM.
> > > This has been my battle for the last three months.
> > >
> > > A little about my Jeep;
> > > Doug thorley header
> > > bored out 62mm throttle
> > > MSD ignition
> > > New catalatic convertor, Flowmaster 50 exhaust Cold air intake 4in
> > > Curry Enterpise lift 33in tires, 4:10 gears, lockers
> > >
> > > What I have done to fix this so far;
> > > -Took it the dealer, they wouldn't touch it.
> > > -I currently have timing chain retarded -5 degree's due to pinging, cut
> > > down on backfiring.
> > > -I also had it advanced +5 degree's, caused a lot more backfiring.
> > > -I also ran the cam at TDC with no advance or timing. This is the
> > > original way I built it.
> > > -Changed TPS
> > > -Changed spark plugs, wires, cap, rotor, and coil. Currently run MSD
> > > ignition which I disconnected and the Jeep barely ran. Connected it
> > > back up and seems to be the only thing keeping it running. So I know
> > > the MSD works -changed O2 sensors -changed fuel pump and filters in
> > > tank, gas cap to.
> > > -Changed fuel injecters to 21LB injectors, stock is around 23.5LB -Put
> > > an air/fuel ratio gauge on it.
> > >
> > > So my latest attempt to get this thing running right truely has me
> > > scratching my head, I left the TPS wire connected disconnected, drove
> > > it and it runs fine. No backfire at 1800+ RPM, it doesn't surge,
> > > hesitate or ping or miss or run rich. It runs great, I can drive it on
> > > the freeway now.
> > >
> > > I am on my last leg with this thing. Anyone have any ideas or
> > > suggestions?????? Please help or i may put the stock cam back in.

Re: New Cam, Jeep will only run without TPS
 

I haven't put the timing gear back to TDC on the timing marks. Its suck
a pain in the ass with the motor installed and 16 bucks for a gasket.
I've done it three times now, the little things have been adding up for
a while. Anyway, I tried to put the dist past the no.1 post. It has
always lined up on the post or to far ahead of the post and doesn't
start or runs real rough.

philthy wrote:
> you have to set the timing gears bac to straight up and then you have to
> properly resync the dist(.need factory manual for procedure) and get the dist
> rotor past #1 cylinder tower of the dist.cap to get it in the correct place
> even if it means spinning oil pump drive a hair and it should drop in
>
> "L.W.(Bill) ------ III" wrote:
>
> > I am a total loss as to how it would run without the Crankshaft
> > Position Sensor. It should default into the safe mode, with no spark
> > advance. Maybe you have your distributor installed in such a way so that
> > it's Cam Position Sensor somehow takes over??????? What's the timing
> > light show, initial and total?
> > God Bless America, Bill O|||||||O
> > mailto:-------------------- http://www.----------.com/
> >
> > jeepinacreek wrote:
> > >
> > > I recently put a new cam in my 1997 Jeep Wrangler 4.0L. I figured it
> > > was a great mod with out totaly stroking the motor. After completing
> > > the buildup and starting it for the first time, I thought great it
> > > runs. Then I ran up and it starting backfiring at around 1800+ RPM.
> > > This has been my battle for the last three months.
> > >
> > > A little about my Jeep;
> > > Doug thorley header
> > > bored out 62mm throttle
> > > MSD ignition
> > > New catalatic convertor, Flowmaster 50 exhaust Cold air intake 4in
> > > Curry Enterpise lift 33in tires, 4:10 gears, lockers
> > >
> > > What I have done to fix this so far;
> > > -Took it the dealer, they wouldn't touch it.
> > > -I currently have timing chain retarded -5 degree's due to pinging, cut
> > > down on backfiring.
> > > -I also had it advanced +5 degree's, caused a lot more backfiring.
> > > -I also ran the cam at TDC with no advance or timing. This is the
> > > original way I built it.
> > > -Changed TPS
> > > -Changed spark plugs, wires, cap, rotor, and coil. Currently run MSD
> > > ignition which I disconnected and the Jeep barely ran. Connected it
> > > back up and seems to be the only thing keeping it running. So I know
> > > the MSD works -changed O2 sensors -changed fuel pump and filters in
> > > tank, gas cap to.
> > > -Changed fuel injecters to 21LB injectors, stock is around 23.5LB -Put
> > > an air/fuel ratio gauge on it.
> > >
> > > So my latest attempt to get this thing running right truely has me
> > > scratching my head, I left the TPS wire connected disconnected, drove
> > > it and it runs fine. No backfire at 1800+ RPM, it doesn't surge,
> > > hesitate or ping or miss or run rich. It runs great, I can drive it on
> > > the freeway now.
> > >
> > > I am on my last leg with this thing. Anyone have any ideas or
> > > suggestions?????? Please help or i may put the stock cam back in.