Morning everyone. I have a 2001 E-350 w/7.3. When I start the truck first thing or when engine is cooled down it starts fine. I checked the high pressure pump pressure and it is 500 - 600 psi start up great. But when engine warms and try to start it it has long crank before starting. I checked pressure and it is between 425 to0 450 and takes awhile for it to get to 500 or better. Is this a cause of the high pressure oil pump ? I changed the oil and still does same thing. All help is greatly appreciated as always.
Also I noticed that after engine is hot and I try to start it, while cranking the engine the oil gauge does not move. I don't know if it supposed to when you crank it or not.
I thought on other 7.3's I've worked on that the gauge builds up pressure

 

This is where an OBDII gauge would be helpful, like Torque Pro, AutoEnginuity, Scangauge, or the like. The numbers you would watch for are Injector Control Pressure (that high oil pressure you're already looking at) and Injector Pressure Regulator. That last one is the signal that controls the ICP, and you want to know if it's "pushing" the High Pressure Oil Pump to deliver more oil than normal, like cranking open the faucet.

If the IPR is higher than normal, there are two very common causes: Tired injector O-rings or tired injectors. The O-rings are a cheap experiment you can try before manning up with the Buck$Zooka for injectors. You can try the "Cody test". Pull the HPOP lines from both heads, then inject air into the heads through the open ports (rag around the air nozzle unless you like oil showers). Gurgling and using air? O-rings. No gurgle on either side? I'd spend a little money on an OBDII gauge before dropping real coin on sticks.

Even if this means added expense to this one fix, the OBDII gauge will pay for itself over and over again on an aging 15-year-old 7.3L. One computer hookup at the stealership is usually about $100, I hook up every time I drive (my drives are never less than 1/2 hour). I was on vacation one time and caught a problem "live" on the gauges before there were any significant symptoms. 1 hour with a wrench and I solved the problem - then drove on. Allowing the problem to progress during my vacation may very well have led to a damaged injector cup.

 

OT...Yo Tug, you mind posting up the tab holder/ Find el cheapo nexus 7 on clist, and want THAT holder. Tired of squinting the eyes, looking at the phone. Thank you sir.

 

Thanks Tugly. I did not mention but my IPR duty cycle is running at 65% while cranking.. Voltage is .85 for sensor and that is with the oil hot. When oil is cool then duty cycle is normal 14.5% . Makes no sense to me

 

I thought I sent that to you before, but my brain is pretty much the consistency of oatmeal right now.

It's an Arkon SM688, I found one on Amazon for about $30-$35 (with shipping). Here is a link that should be usable on a 2" touch screen (be sure to click the video to see some of the cool features):

[LINK]


This is consistent with O-rings or injectors.

 

When is the last time that you changed your fuel filter? Was it black? If you have not changed it in a while, considering doing so. If it is/was black, this would be consistent with o-rings going south...if you are only building 400-500 psi at 65% IPRDC then the fuel filter would likely be black.

How many miles are on your truck and what is the oil level? Is it using any oil?

 

Everything checks. I noticed that when I'm cranking the engine, I have no oil pressure while cranking then when it starts I have oil pressure. could this be a related problem??

 

That is normal on my 2002.


Next time you are about to start hot and expect the problem, pop the allen screw off the top of the HPOP reservoir. Oil should be within an inch of the top. Replace allen screw before attempting to start.


Sometimes the solenoid on the IPR will fail when hot. Next time be ready with a Big Gulp of ice, pour it on the IPR and let it soak and cool for a couple minutes. If it starts get yourself a new IPR, the solenoid is not available separately.

 

it's a brand new ipr and new hpop

 

Ok on with my problem...I put a brand new IPR in and it still is hard to start. It will not stay running until I pull the harness off of the pressure sensor. If I plug the sensor back in it almost shuts down and finally it does shut down. The sensor is new as well. Now I'm really at a loss.

 

Ok here's what all I've put on... HPOP , IPR valve , ICP sensor, Fuel Pump, Fuel filter
Now when I start the truck up it runs fine for about 1 minute then it shuts down like someone turned key off. I disconnect the icp sensor and it will run for about 10 to 20 minutes then it will shut off the same way. The only time it will throw a code is when it shuts down so scanning for codes means nothing. The fuel pressure reading after the pump is 65 psi so I know it is getting fuel. The cranking pressure is between 500 - 600 psi so I know the hpop is good. The hpop reservoir is within specs when it shuts down. Now I'm really at a loss.

 

A No Start or Hard Start - When Warm/Hot is almost always the IPR. But, I see you have replaced the IPR. Hopefully OEM.

The next place to seek would be oil in the fuel bowl which you state you have no oil in the Fuel Bowl..

You say "The cranking pressure is between 500 - 600 psi so I know the hpop is good"

That is not an indication of a good HPOP by itself. The ICP should steadily climb throughout cranking upwards to 2,000 or more psig if the engine is not starting.

Also, check to ensure the Tin Nut is secure on the pintail of the IPR. And, if your feeling board, check to ensure there is OMES = 10.2 - 10.6 While it's not likely you got one bad out of the box, it does happen.

With that said, If all this leads to no issues. The next step is to Air test the HPOS.

AIR TESTING THE HPO SYSTEM

Tools: Adaptor (M12 1.5 - Same as Fuel Port), Air Compressor capable of maintaining 90-100 psig, Adaptors which will allow connection to the M12 1.5.

1. Selecting either the Right or Left Head, Remove the M12 1.5 Bolt or the ICP and insert the M12 1.5 Adaptor.

2. Connect Shop Air and allow to run uninterrupted. The entire HPO System will fill with the air. Eventually it will find either a natural or problem area to escape. Problem areas will be much louder and distinctive.

3. Listen closely to each valve cover. Air leaking into the valve cover is escaping by way of an O-Ring, Loose Injector, or other Anomaly which is preventing the building of HP in the HPO System.

4. Repeat on other Head as some will only present problem area’s when pressure is at its greatest at the shortest distance, sometimes requiring both heads to be tested.

With any assumed anomalies, you should remove both valve covers and witness oil from the deflectors as being uniform and look closely at the injector base as one may be loose or an O-Ring is failing or, has failed allowing oil to escape and not build pressure in the HPO System..

Some parameters which will assist as Mr. Tugly states above would be:

Tools: OBD-II On-Board Diagnostics, Phase 2 Vehicle Media Communications Unit (Scanner)

1. Select the parameters indicated from the Scan Tool parameter list and monitor while cranking engine.

Data List Monitoring Parameter:

V-PWR 10.5 VDC Minimum. (The CMP may fall out of the PCM circuit if vehicle voltage falls below 10.5v).

RPM 100 RPM Minimum (0 - CMP Suspect)
ICP 500 PSI or 3.4 MPAM Minimum the ICP should steadily climb during cranking. This indicates a healthy HPOP depending upon how high it climbs.

ICPv (KOEO) Spec 0.20v - 0.30v

FUEL PW: 1 MS - 6 MS (<1 / >6 IDM Suspect)

V-PWR - If indicating a low voltage condition, check battery voltage, charging system or power and ground circuits to the PCM.

DC% - Cranking NTE 20% / 65% is closed. (IPR Suspect)

2. RPM - Low RPM could be an indication of starting / charging system problems **

3. No RPM indicated with the engine cranking - could be CMP circuit fault, check for DTC’s.

4. ICP - A minimum of 500 PSI (3.4 mPa) is required before the injectors are enabled. No or low oil in the reservoir, system leakage, injector O-Rings, or faulty IPR could cause pressure loss.
Note: If no RPM signal is received, IPR duty cycle will default to 14%

5. FUEL PW - Even though a 1 to 6 mS FUEL PW is shown, it’s possible the IDM did not receive the signal due to a CI or FDCS circuit fault or internal IDM failure.

6. MAT: Manifold Air Temperature The PCM uses this signal to adjust fuel and timing.

7. VFD (Volume Fuel Desired)

8. MFD (Mass Fuel Desired)

 

I think the run for a minute and cutting off is the truck not getting a CPS reading.

Out of curiousity, what weight oil do u run?

 

Well did manage to get it figured out. It turned out to be the IDM. Didn't throw codes and it was my last resort but running perfectly now. Thanks for all your help in trying to resolve this issue.

 

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