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Hi, I'm Chad. Welcome to JustAnswer. I'm reviewing your question and I will be posting your reply ASAP.
Hey how are you
you must have check engine light ,is it on or flashing ?
is the O/D button flashing on the shifter ?
when was trans serviced last ?
how many miles, do you use it for towing service ?
Please let me know
ASE Certified Technician
lets start here and we go from there
Hello, different expert here. My name is James.
Code P1670 can be set as a ghost code. The P1211 is the one that will help get your truck running properly. Before going through the pinpoint test, can you tell me when the oil was last changed, if it is full on the dipstick, and when the fuel filter was serviced last?
Alright. Are you using a scan tool that can read the sensors, or just a code reader?
Ok, the next thing to do is check fuel pressure at the fuel filter housing. Do you have a fuel pressure gauge?
You'll want to see abou 55 psi at the housing
Ok, some don't have the Schrader at the filter housing. If not, disconnect the fuel lines at the heads, one at a time and check pressure there. At the heads you should have 30 psi minimum
Ok perfect. Using your scanner, Monitor the ICP pressure with the key on and the engine off. Does it read 0 psi?
Ok perfect and about 550 at idle? Is that on a cold or warm engine?
I apologize. My last response did not post.
Please check the icp at hot idle, then run it at wide open throttle at the rev limiter when hot and post the icp pressure and the ipr percentage.
Hi ,my name is***** will be glad to help. Pressure test the high pressure rail with shop air and listen for air leaks under the valve covers.... If so reseal the injectors. If okay try 12 volts to the IPR and see if you have over 3000 PSI ICP pressure with a 5000 PSI gauge in the ICP port. If that is okay it means the HPOP is good. Then verify the ICP sensor and IPR are good. Check your fuel pressure and verify it is in specs of around 75-85 PSI and there are no leaks or restrictions. Let me know
I tried calling. Let me know the best times to reach you EST.
that is the minimum or low end of the specs. What is your e mail? Ill send over all your test info.
Click on this link and you will have all that you need in detail. Ill call again Monday.
Thanks for the update. Did you get the publication I posted in the troubleshooting link?
Fuel pressure testing and injection control pressure testing for starters.
calling you now
with the IPR disconnected and 12 volts applied and a 5000 PSI mechanical guage in the ICP sensor port you should see full HPOP pressure over 3000PSI for a good pump. Before this test be sue there are no leaking injector o rings by applying shop air to the ICP sensor port and listen for air leaking under the valve covers. Run through the IPR test . If okay try disconnecting the ICP and see if it defaults to 725 PSI as it should. All these tests are in the publication I sent. Let me know the results.
Maybe that was true 25 years ago and prior but these engines have electronic controls now and are much more advanced Pages 28-30, pages 71-73, the schematics, the theory and operation of the fuel system, the fuel regulator location and specs, etc.
I have this same engine in my road service truck. I have an update pressure regulating spring in my filter housing and getting between 80-90 PSI. However, If you look at the guide I posted, it gives a test flow chart to go through and then goes over the next step depending on the results. 30 PSI fuel supply is the Min spec so if you dont have air in the system and have 55 PSI, that is sufficient to start. What you dont have is 500 PSI Min that the ECM needs to see from the ICP sensor to allow or command the injectors to fire. Verify engine speed signal as well to the ECM. First troubleshoot the low ICP pressure.
Try a rubber tipped blow gun and hold it there firmly
Hi James, I was out on the road yesterday. Sorry for the delay. There should be no leaks in the high pressure rail so if air is leaking under the valve cover it will need to be repaired. 4000 PSI is a good sign and indicates your pump (HPOP) is good and the IPR seems to be functioning.
If comparing ICP pressure from the mechanical gauge and what the ICP sensor is sending to the ECM, Do the values match? cranking the engine with the ICP sensor unplugged will cause the ECM to use default programmed values for ICP pressure. It is the ICP sensor message that tells the ECM what the pressure is.... Is that message to the ECM accurate?
Let me know what the scan tool reads for default with the sensor plugged in and also unplugged.... Unplugged should be a default programmed value and plugged in obviously what the sensor is sending to the ECM...
It proves the pump is good but either the IPR is not responding or getting improper signal from the ECM. The ECM uses the ICP sensor info to command the IPR position.
Also with leaks the pressures will not hold or be consistant
Hi, sorry for the delay, I dont know why your response did not go to my in box until this last one.
The ECM controls the IPR position but even with a good pump, leaks in the high pressure rail/injector o rings will not allow pressure to maintain causing low ICP pressure.
Yes the external o rings that seal the injectors on installation.
Thanks for the update. Let me know
Thanks for the update. There will be some oil splash at idle but only if there is a bad injector leak should it make too much of a mess.
Put some cardboard up as a shield
Thanks for the update. Check the EBP sensor on the tube connected to the passenger side exhaust manifold as if that tub is leaking or the sensor is bad or wiring the ECM will not command the turbo for boost and boost will be cut back. Also if the port to that tube fitting in the manifold is blocked it wont send manifold pressure to the sensor. Let me know
I am referring to the Exhaust back pressure sensor. The tube for it is connected to the passenger side exhaust manifold and the sensor is mounted at the end of the tube at the front of the engine towards the passenger side. If that tube is leaking or the sensor is bad or wiring the ECM will not command the turbo for boost and boost will be cut back. Also if the port to that tube fitting in the manifold is blocked it wont send manifold pressure to the sensor.