New PMD still Problems...

[Burning oil]

I change my bet to grounds. Where are you taping in for fuel gauge?

 

[buddy]

What would be really useful for you is to purchase or find an OBD1 to USB ALDL cable so you can hook the truck up to a computer. And Download the free GMTDScan scanner software to evaluate your idle timing and fuel rates. cables can be found for $60 I think, a great investment.

 

[Caskey]

If you have pressure you likely dont have a fuel sock problem. And if you have constant pressure even during sputtering is not an OPS issue.

So checking IP input and return with clear line is a good next step.

So anyone have a pic of this hose so i know im doing the right none? Im

I change my bet to grounds. Where are you taping in for fuel gauge?

I wish i could i could tell ya but i have no clue. Where should i look for it?

 

[Burning oil]

I wish i could i could tell ya but i have no clue. Where should i look for it?

Trace the hose or wire from gauge to the sender or other end of hose.

 

[bison]

So anyone have a pic of this hose so i know im doing the right none? Im
I wish i could i could tell ya but i have no clue. Where should i look for it?

Here ya go

 

[Caskey]

What would be really useful for you is to purchase or find an OBD1 to USB ALDL cable so you can hook the truck up to a computer. And Download the free GMTDScan scanner software to evaluate your idle timing and fuel rates. cables can be found for $60 I think, a great investment.

Can you get me a link to this? Ill order it today.

 

[buddy]

http://www.amazon.com/dp/B001NQGLIA/?tag=jhuntlink-20

or the source from that link is http://www.aldlcable.com/

And the software is from engh motors. The pay software is awesome, allows you to shut off injection to cylinders, set the timing, and do other types of functions. But you can get all the sensor readings with the free version. Engh also sells cable in a package with the pay version of the software

Also check to make sure you dont still have an Optical Sensor filter on the harness that plugs into the OS. If you do remove it.

 

[jrsavoie]

Tell me more about this optic sensor filter. I thought that was the replacement part that heath sells to reduce fish biting. I bought one for the Tahoe.

 

[Caskey]

http://www.amazon.com/dp/B001NQGLIA/?tag=jhuntlink-20

or the source from that link is http://www.aldlcable.com/

And the software is from engh motors. The pay software is awesome, allows you to shut off injection to cylinders, set the timing, and do other types of functions. But you can get all the sensor readings with the free version. Engh also sells cable in a package with the pay version of the software

Also check to make sure you dont still have an Optical Sensor filter on the harness that plugs into the OS. If you do remove it.

How do i check to see if i have that? Im sure i do since my truck is stock all around.

 

[buddy]

Just go look at the harness going to the OS, its a little black box with wires coming out to connectors. Its not necessary in most trucks. It is used to filter power to the OS. It has a Bypass capacitor between the PCM 5V reference power and ground wires, as well as an inline resistor. This is common for ICs on the end of long wires that can pick up EMI, or create inductance. Some peoples alternators can cause a lot of EMI, as well as PMD on the IP, but if you relocated it that helps.

 

[Turbine Doc]

Just tested again and had no problems at idle stayed 5-6 psi. Rollin down the road at did fine. I got it to sputter while hooked up to the guage and didnt see a drop pressure. So back to square one. Next i will take the fuel filter off and check it for clog etc. How do i check my fuel sock?>

Can you expand on this a little, especially the did fine part, did you see gauge move while driving or possibly was the hose pinched while driving and the reading was "dead headed" to a fixed reading it happened to me is why I ask, and led me to some additional troubleshooting pain.

A dirty sock did me in just as described above, could be electrical as well, so it merits checking both out, on my snotty sock, I could clear it by removing the inlet line of the lift pump & blowing back towards the tank thru it, with the tank fill cap off (don't want to swell the tank) 3-5 psi is all u need, which will temporarily clear the sock & sock bypass of snot, e3asy enough to do if your electrical trouble shooting does not reveal anything

 

[Caskey]

Can you expand on this a little, especially the did fine part, did you see gauge move while driving or possibly was the hose pinched while driving and the reading was "dead headed" to a fixed reading it happened to me is why I ask, and led me to some additional troubleshooting pain.

A dirty sock did me in just as described above, could be electrical as well, so it merits checking both out, on my snotty sock, I could clear it by removing the inlet line of the lift pump & blowing back towards the tank thru it, with the tank fill cap off (don't want to swell the tank) 3-5 psi is all u need, which will temporarily clear the sock & sock bypass of snot, e3asy enough to do if your electrical trouble shooting does not reveal anything

Now that you say it it might have been pinched. When i pulled the line off after the test it had fuel in it. Could that cause a bad reading?

 

[Turbine Doc]

Should have some fuel in bottom end but not full of fuel, you'll want to see same sort of pulsations while driving that you see at idle with hood open, if not then your hose quite possibly is pinched, it's worth checking out.

 

[Caskey]

Should have some fuel in bottom end but not full of fuel, you'll want to see same sort of pulsations while driving that you see at idle with hood open, if not then your hose quite possibly is pinched, it's worth checking out.

Yeah i guess i will go do the test again. Anyway i can make sure that doesnt happen again?

 

[Turbine Doc]

Just be careful how you route the hose, out the back of the fender there is a gap by the hood lift spring/support, that lets you run it under the hood, and run it into the cab with the window down, and go for a drive, you should be able to tell right away, your gauge should move at idle with hood down like it did with hood up.

Then when on highway when you punch it, you should see the pressure drop from your steady state pressure reading to some point below that, if pressure drops to 0 you have fuel delivery issues. we need to know what pressures are at steady state and when you punch APP to the floor

 

[Caskey]

Just be careful how you route the hose, out the back of the fender there is a gap by the hood lift spring/support, that lets you run it under the hood, and run it into the cab with the window down, and go for a drive, you should be able to tell right away, your gauge should move at idle with hood down like it did with hood up.

Then when on highway when you punch it, you should see the pressure drop from your steady state pressure reading to some point below that, if pressure drops to 0 you have fuel delivery issues. we need to know what pressures are at steady state and when you punch APP to the floor

How many times should i turn the t valve? i did 4 the last time and it filled with diesel.

 

[jrsavoie]

Just go look at the harness going to the OS, its a little black box with wires coming out to connectors. Its not necessary in most trucks. It is used to filter power to the OS. It has a Bypass capacitor between the PCM 5V reference power and ground wires, as well as an inline resistor. This is common for ICs on the end of long wires that can pick up EMI, or create inductance. Some peoples alternators can cause a lot of EMI, as well as PMD on the IP, but if you relocated it that helps.

Is that the same part I bought to cure the fishbite on the 95 Tahoe?
To eliminate it, Do you just cut the box out and splice it back in?
Which vehicles can you safely eliminate it?

 

[Turbine Doc]

Full open filter mgr drain on the hose but there should be a small dead air space between the gauge and the drains fuel column, the fuel should not compress all the air in the line, what kind of a gauge are you using ?, it won't hurt the reading to have it full of fuel unless the gauge is not capable of handling fluids

 

[bison]

Full open filter mgr drain on the hose but there should be a small dead air space between the gauge and the drains fuel column, the fuel should not compress all the air in the line, what kind of a gauge are you using ?, it won't hurt the reading to have it full of fuel unless the gauge is not capable of handling fluids

some times the manual gauges are hard to read properly cuz of the needle flutter.
A snubber on the gauge will be way more accurate.

 

[Caskey]

Full open filter mgr drain on the hose but there should be a small dead air space between the gauge and the drains fuel column, the fuel should not compress all the air in the line, what kind of a gauge are you using ?, it won't hurt the reading to have it full of fuel unless the gauge is not capable of handling fluids

The guage is capable its the exact one that is suggested in the ip ops trouble shotting thread.

some times the manual gauges are hard to read properly cuz of the needle flutter.
A snubber on the gauge will be way more accurate.

Snubber? Sorry im 19 and still learning stuff what is that?