Another 7.3 no start..

littleredstroker · May 9, 2014

New ipr in, no difference. Gonna Crack a plug in one of the heads and see if I can tell if it's even pumping oil. .

Sent from my SAMSUNG-SM-G900A using Tapatalk

PSD POWER007 · May 10, 2014

Pull the valve cover and check for oil pouring out around the base of the injector. Bad oring would be my guess.

littleredstroker · May 10, 2014

PSD POWER007 said:
Pull the valve cover and check for oil pouring out around the base of the injector. Bad oring would be my guess.

Possible. Not ruling that out, but these of rings have maybe 5k miles on them , 15k on the injectors themselves. I guess that's as probable as a crapped adrenaline with 20k

Sent from my SAMSUNG-SM-G900A using Tapatalk

TyCorr · May 10, 2014

No scangauge? Is it building icp? The poormans gauge? Listen. The truck will wing over effortlessly and as hpo comes up the cranking will slow as the starter labors to crank an hpop full of oil. Id crack a line or head fitting BEFORE I started checking injectors.

littleredstroker · May 10, 2014

TyCorr said:
No scangauge? Is it building icp? The poormans gauge? Listen. The truck will wing over effortlessly and as hpo comes up the cranking will slow as the starter labors to crank an hpop full of oil. Id crack a line or head fitting BEFORE I started checking injectors.

yes, same number comes up on the scangauge, 65xxx psi. duty cycle climbs up to 90%in just a few seconds just like before. It never changes tone while cranking cranks fast and easy never slows down, never smokes. It just isn't building hpo pressure. It honestly sounds exactly like its out of oil, which is not the case...

littleredstroker · May 10, 2014

I guess I never noticed the LPO pressure... i will have to check that tonight when i get off work. LPOPs usually go out like this ? ive always had good oil pressure.

edit: It doesn't make sense for resivior to be full tho..

wchsnowremoval · May 10, 2014

I have seen icp show crazy psi and duty cycles when the Idm fuse blew.

wchsnowremoval · May 10, 2014

It may have the oil pressure and the fuel to work but no communication from Idm to command injects to fire. Just a thought.

littleredstroker · May 10, 2014

wchsnowremoval said:
It may have the oil pressure and the fuel to work but no communication from Idm to command injects to fire. Just a thought.

If Idm wasn't working , It wouldn't buzz on the buzz test right

Sent from my SAMSUNG-SM-G900A using Tapatalk

ghohouston · May 10, 2014

Correct

TERRCO · May 11, 2014

Maybe I missed it but were you getting smoke? Are you getting any fuel to the injectors?

2000wa250 · May 11, 2014

Only time I've ever seen those kind of numbers on my scan gauge (psi wise) were with an unplugged ICP sensor. Have you tried unplugging the sensor and cranking it so the pcm defaults and calls for the injectors to fire?

My thinking here is your ICP sensor **** the bed, and is sending out a voltage the pcm/scan gauge doesn't know how to interpret. No signal from ICP sensor = no command to fire. If res is staying full there's two really only three options.... hpo leak (external would be obvious, internal is limited to o rings), pump is shot (oil is never leaving the res) or ICP is bad/pcm isn't commanding sticks to fire. Need to verify that pcm is sending the fire signal. Pull a vc and have someone crank while you listen. Should hear solenoids clicking. Or unplug ICP sensor and see if that changes anything.

Depending on what you find easier, you can either pull the hpop or pull sticks to test for the first two options. Personally only time I've had a no start because of o rings the res would not stay full if truck was warm and sat for a decent amount of time.

To test hpop pull it out, cover the intake hole with your finger (small hole to the 4-5 o'clock of the drive) and turn the pump over. If pump is dead, there will be zero suction. This is really obvious if you throw a pair of latex gloves on when you test it and cover the hole with your thumb.

Fwiw my money is on no command to fire injectors.

Sent from my SCH-I545 using Tapatalk

littleredstroker · May 11, 2014

2000wa250 said:
Only time I've ever seen those kind of numbers on my scan gauge (psi wise) were with an unplugged ICP sensor. Have you tried unplugging the sensor and cranking it so the pcm defaults and calls for the injectors to fire?

My thinking here is your ICP sensor **** the bed, and is sending out a voltage the pcm/scan gauge doesn't know how to interpret. No signal from ICP sensor = no command to fire. If res is staying full there's two really only three options.... hpo leak (external would be obvious, internal is limited to o rings), pump is shot (oil is never leaving the res) or ICP is bad/pcm isn't commanding sticks to fire. Need to verify that pcm is sending the fire signal. Pull a vc and have someone crank while you listen. Should hear solenoids clicking. Or unplug ICP sensor and see if that changes anything.

Depending on what you find easier, you can either pull the hpop or pull sticks to test for the first two options. Personally only time I've had a no start because of o rings the res would not stay full if truck was warm and sat for a decent amount of time.

To test hpop pull it out, cover the intake hole with your finger (small hole to the 4-5 o'clock of the drive) and turn the pump over. If pump is dead, there will be zero suction. This is really obvious if you throw a pair of latex gloves on when you test it and cover the hole with your thumb.

Fwiw my money is on no command to fire injectors.

Sent from my SCH-I545 using Tapatalk

Once again, if that was the case wouldn't the injectors not buzz with a buzz test if the signal wasn't coming through...

TERRCO said:
Maybe I missed it but were you getting smoke? Are you getting any fuel to the injectors?

Zero fuel. No smoke.

Sent from my SAMSUNG-SM-G900A using Tapatalk

wchsnowremoval · May 11, 2014

I would try to swap in a known good idm. Correct me if I'm wrong but I believe the buzz test is performed through a different part of the Idm then when it's commanded to "run".The icp pressure would bleed off it the Idm where commanding the injectors on while cranking.

2000wa250 · May 11, 2014

littleredstroker said:
Once again, if that was the case wouldn't the injectors not buzz with a buzz test if the signal wasn't coming through...

Zero fuel. No smoke.

Sent from my SAMSUNG-SM-G900A using Tapatalk