tech questions: 93 wrangler, 93 gr cher
 

howdy y'all, two tech questions:

93 wrangler 4.0 ticking sound early in the
morning, only has happened a couple times. i want
to say cold weather ping, but it's been way colder
with no ping. it sounds like ignition or valve
train related? like every other revolution tick
sound. it went away after a couple minutes
driving, and then back to purring like a kitten.

93 grand cherokee 4.0 (buying for my wife) has a
hard time starting after it's sat for a while,
overnight not so bad, but a couple days and she
cranks for a while. i want to say fuel pump check
valve is draining back. sound about right? if this
is it, i might build a timer circuit to bump the
pressure before cranking.

--
Ben Jerew AKA PolarPuppy
ASE Certified Master Technician
New Country Lexus of Latham, NY, USA
Amateur Off-Roader 93 YJ 4.0l 3spd

Re: tech questions: 93 wrangler, 93 gr cher
 

MudPuppy76 did pass the time by typing:
> howdy y'all, two tech questions:
>
> 93 wrangler 4.0 ticking sound early in the
> morning, only has happened a couple times. i want
> to say cold weather ping, but it's been way colder
> with no ping. it sounds like ignition or valve
> train related? like every other revolution tick
> sound. it went away after a couple minutes
> driving, and then back to purring like a kitten.

Probably needs an oil change. The I6 isn't the worlds
most quiet engine when it's older. :) It could be
your getting a teeny crack in the exhaust pipe, that
will sound like a tick till the metal heats up and
seals it off. Eventually it will sound like a diesel
and you will have to replace it. (they all crack)
linky: http://members.cox.net/douglas.wilson/banks/


> 93 grand cherokee 4.0 (buying for my wife) has a
> hard time starting after it's sat for a while,
> overnight not so bad, but a couple days and she
> cranks for a while. i want to say fuel pump check
> valve is draining back. sound about right? if this
> is it, i might build a timer circuit to bump the
> pressure before cranking.

Either fuel pump check valve or fuel rail pressure
regulator has failed. Get a fuel pressure gauge and
check the rail. 32 psi at idle, take the hose off the
regulator and it should jump 3-4psi, turn the engine
off and the pressure should stay level for more than an
hour. To check which one is leaking you have to use
a special hose that can be clamped. Clamping the OEM
hoses isn't a good idea. At two days I wouldn't be worrying.
Just tell here to turn the key on, then off, wait a sec,
then on again, then start. You might need to replace the
fuel filter.


--
-- DougW -- 93 ZJ 4.0 http://members.cox.net/wilsond
HESCO Supercharger - 300W IASCA Stereo - Edelbrock IAS Shocks
Gibson Exhaust - rear DCpower - custom gauge install - Stillen Rotors
Banks Header - and BEER, in the fridge!

Re: tech questions: 93 wrangler, 93 gr cher
 

MudPuppy76 did pass the time by typing:
> howdy y'all, two tech questions:
>
> 93 wrangler 4.0 ticking sound early in the
> morning, only has happened a couple times. i want
> to say cold weather ping, but it's been way colder
> with no ping. it sounds like ignition or valve
> train related? like every other revolution tick
> sound. it went away after a couple minutes
> driving, and then back to purring like a kitten.

Probably needs an oil change. The I6 isn't the worlds
most quiet engine when it's older. :) It could be
your getting a teeny crack in the exhaust pipe, that
will sound like a tick till the metal heats up and
seals it off. Eventually it will sound like a diesel
and you will have to replace it. (they all crack)
linky: http://members.cox.net/douglas.wilson/banks/


> 93 grand cherokee 4.0 (buying for my wife) has a
> hard time starting after it's sat for a while,
> overnight not so bad, but a couple days and she
> cranks for a while. i want to say fuel pump check
> valve is draining back. sound about right? if this
> is it, i might build a timer circuit to bump the
> pressure before cranking.

Either fuel pump check valve or fuel rail pressure
regulator has failed. Get a fuel pressure gauge and
check the rail. 32 psi at idle, take the hose off the
regulator and it should jump 3-4psi, turn the engine
off and the pressure should stay level for more than an
hour. To check which one is leaking you have to use
a special hose that can be clamped. Clamping the OEM
hoses isn't a good idea. At two days I wouldn't be worrying.
Just tell here to turn the key on, then off, wait a sec,
then on again, then start. You might need to replace the
fuel filter.


--
-- DougW -- 93 ZJ 4.0 http://members.cox.net/wilsond
HESCO Supercharger - 300W IASCA Stereo - Edelbrock IAS Shocks
Gibson Exhaust - rear DCpower - custom gauge install - Stillen Rotors
Banks Header - and BEER, in the fridge!

Re: tech questions: 93 wrangler, 93 gr cher
 

MudPuppy76 did pass the time by typing:
> howdy y'all, two tech questions:
>
> 93 wrangler 4.0 ticking sound early in the
> morning, only has happened a couple times. i want
> to say cold weather ping, but it's been way colder
> with no ping. it sounds like ignition or valve
> train related? like every other revolution tick
> sound. it went away after a couple minutes
> driving, and then back to purring like a kitten.

Probably needs an oil change. The I6 isn't the worlds
most quiet engine when it's older. :) It could be
your getting a teeny crack in the exhaust pipe, that
will sound like a tick till the metal heats up and
seals it off. Eventually it will sound like a diesel
and you will have to replace it. (they all crack)
linky: http://members.cox.net/douglas.wilson/banks/


> 93 grand cherokee 4.0 (buying for my wife) has a
> hard time starting after it's sat for a while,
> overnight not so bad, but a couple days and she
> cranks for a while. i want to say fuel pump check
> valve is draining back. sound about right? if this
> is it, i might build a timer circuit to bump the
> pressure before cranking.

Either fuel pump check valve or fuel rail pressure
regulator has failed. Get a fuel pressure gauge and
check the rail. 32 psi at idle, take the hose off the
regulator and it should jump 3-4psi, turn the engine
off and the pressure should stay level for more than an
hour. To check which one is leaking you have to use
a special hose that can be clamped. Clamping the OEM
hoses isn't a good idea. At two days I wouldn't be worrying.
Just tell here to turn the key on, then off, wait a sec,
then on again, then start. You might need to replace the
fuel filter.


--
-- DougW -- 93 ZJ 4.0 http://members.cox.net/wilsond
HESCO Supercharger - 300W IASCA Stereo - Edelbrock IAS Shocks
Gibson Exhaust - rear DCpower - custom gauge install - Stillen Rotors
Banks Header - and BEER, in the fridge!

Re: tech questions: 93 wrangler, 93 gr cher
 

MudPuppy76 <"<moc.rr.pacyn"@"pupralop"> proclaimed:
> howdy y'all, two tech questions:
>
> 93 wrangler 4.0 ticking sound early in the morning, only has happened a
> couple times. i want to say cold weather ping, but it's been way colder
> with no ping. it sounds like ignition or valve train related? like every
> other revolution tick sound. it went away after a couple minutes
> driving, and then back to purring like a kitten.
>
> 93 grand cherokee 4.0 (buying for my wife) has a hard time starting
> after it's sat for a while, overnight not so bad, but a couple days and
> she cranks for a while. i want to say fuel pump check valve is draining
> back. sound about right? if this is it, i might build a timer circuit to
> bump the pressure before cranking.
>

Quick diagnostic on the ZJ would be to turn the key on, wait a coupla
seconds. If it starts right away then, the fuel system is losing
pressure somewhere. On the 93 don't know if there is also a fuel
rail check valve.

Re: tech questions: 93 wrangler, 93 gr cher
 

MudPuppy76 <"<moc.rr.pacyn"@"pupralop"> proclaimed:
> howdy y'all, two tech questions:
>
> 93 wrangler 4.0 ticking sound early in the morning, only has happened a
> couple times. i want to say cold weather ping, but it's been way colder
> with no ping. it sounds like ignition or valve train related? like every
> other revolution tick sound. it went away after a couple minutes
> driving, and then back to purring like a kitten.
>
> 93 grand cherokee 4.0 (buying for my wife) has a hard time starting
> after it's sat for a while, overnight not so bad, but a couple days and
> she cranks for a while. i want to say fuel pump check valve is draining
> back. sound about right? if this is it, i might build a timer circuit to
> bump the pressure before cranking.
>

Quick diagnostic on the ZJ would be to turn the key on, wait a coupla
seconds. If it starts right away then, the fuel system is losing
pressure somewhere. On the 93 don't know if there is also a fuel
rail check valve.

Re: tech questions: 93 wrangler, 93 gr cher
 

MudPuppy76 <"<moc.rr.pacyn"@"pupralop"> proclaimed:
> howdy y'all, two tech questions:
>
> 93 wrangler 4.0 ticking sound early in the morning, only has happened a
> couple times. i want to say cold weather ping, but it's been way colder
> with no ping. it sounds like ignition or valve train related? like every
> other revolution tick sound. it went away after a couple minutes
> driving, and then back to purring like a kitten.
>
> 93 grand cherokee 4.0 (buying for my wife) has a hard time starting
> after it's sat for a while, overnight not so bad, but a couple days and
> she cranks for a while. i want to say fuel pump check valve is draining
> back. sound about right? if this is it, i might build a timer circuit to
> bump the pressure before cranking.
>

Quick diagnostic on the ZJ would be to turn the key on, wait a coupla
seconds. If it starts right away then, the fuel system is losing
pressure somewhere. On the 93 don't know if there is also a fuel
rail check valve.

Re: tech questions: 93 wrangler, 93 gr cher
 

MudPuppy76 <"<moc.rr.pacyn"@"pupralop"> wrote:
> 93 grand cherokee 4.0 (buying for my wife) has a
> hard time starting after it's sat for a while,
> overnight not so bad, but a couple days and she
> cranks for a while. i want to say fuel pump check
> valve is draining back. sound about right? if this
> is it, i might build a timer circuit to bump the
> pressure before cranking.

Put a gauge on it and monitor bleeddown pressure overnight. If it is
your pump checkball, then I would think you would want to replace the
pump - esp. if it is a high mileage unit, rather than insert a homemade
timer into the FP circuit. The pump should run Key On anyway. Its the
operation of the injectors during cranking that bleed the fuel line of
air when you have a fuel drainback problem, not fuel pressure alone.

And incase this is just coincidence that the engine only has trouble on
extended sits --- the 4.0 of that era had problems with its crank
sensor. Not sure if it was still a problem part by 1993 though. Their
output level would weaken at cranking speeds and cause either a no
start or a long crank. Just something to think about,

Toyota MDT in MO

Re: tech questions: 93 wrangler, 93 gr cher
 

MudPuppy76 <"<moc.rr.pacyn"@"pupralop"> wrote:
> 93 grand cherokee 4.0 (buying for my wife) has a
> hard time starting after it's sat for a while,
> overnight not so bad, but a couple days and she
> cranks for a while. i want to say fuel pump check
> valve is draining back. sound about right? if this
> is it, i might build a timer circuit to bump the
> pressure before cranking.

Put a gauge on it and monitor bleeddown pressure overnight. If it is
your pump checkball, then I would think you would want to replace the
pump - esp. if it is a high mileage unit, rather than insert a homemade
timer into the FP circuit. The pump should run Key On anyway. Its the
operation of the injectors during cranking that bleed the fuel line of
air when you have a fuel drainback problem, not fuel pressure alone.

And incase this is just coincidence that the engine only has trouble on
extended sits --- the 4.0 of that era had problems with its crank
sensor. Not sure if it was still a problem part by 1993 though. Their
output level would weaken at cranking speeds and cause either a no
start or a long crank. Just something to think about,

Toyota MDT in MO

Re: tech questions: 93 wrangler, 93 gr cher
 

MudPuppy76 <"<moc.rr.pacyn"@"pupralop"> wrote:
> 93 grand cherokee 4.0 (buying for my wife) has a
> hard time starting after it's sat for a while,
> overnight not so bad, but a couple days and she
> cranks for a while. i want to say fuel pump check
> valve is draining back. sound about right? if this
> is it, i might build a timer circuit to bump the
> pressure before cranking.

Put a gauge on it and monitor bleeddown pressure overnight. If it is
your pump checkball, then I would think you would want to replace the
pump - esp. if it is a high mileage unit, rather than insert a homemade
timer into the FP circuit. The pump should run Key On anyway. Its the
operation of the injectors during cranking that bleed the fuel line of
air when you have a fuel drainback problem, not fuel pressure alone.

And incase this is just coincidence that the engine only has trouble on
extended sits --- the 4.0 of that era had problems with its crank
sensor. Not sure if it was still a problem part by 1993 though. Their
output level would weaken at cranking speeds and cause either a no
start or a long crank. Just something to think about,

Toyota MDT in MO