How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site. Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Daniel Wilson Your Own Question
Daniel Wilson
Daniel Wilson,
Category: Ford
Satisfied Customers: 5564
Experience:  Owner at DJ Wilson
Type Your Ford Question Here...
Daniel Wilson is online now
A new question is answered every 9 seconds

99 F350 7.3 Diesel....Has very little power...Will barely

This answer was rated:

99 F350 7.3 Diesel....Has very little power...Will barely pull out of it's own track from start....Seems to have a little more power after getting up to speed and shifting in to higher gear

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

Thank You

Chad Farhat

ASE Certified Technician

lets start here and we go from there

Customer: replied 1 month ago.
I'm doing fine other than having a broken truck....Oddly, there is no check engine light because there are some codes..The codes that I feel are relevant to this problem are P1670--P1247--P1248--P1211....The O/D light is not flashing and I do not know how long it's been for Trans servicing and the truck is used as needed but not always for towing
Ok let's work on ,can you run a pin point test if send you
DTC p1670
Please read most possible cause here for p1211 , you need to start with p1211
Check these fuses that is the schematics
Customer: replied 1 month ago.
I will try to run pinpoint tests when I get a chance but my experience has been that at a certain point, I either don't have the right scan tool or I cannot find something they are talking about.
Well try to do as much , if want to guess m pcm issue atbyear and mileage but we need testing this fault it could all listed ,sorry wish I can give a exact answer but will be a guess and you end up throwing parts at it ,start with p1211Read below how to get back in touch when u doPlease Use The Stars on Top of Your screen To Rate me so I can be compensated for my time and resources .
If more help is needed just reply back and we can continue
You can copy the link page and pasted in your browser and will open up the conversation between us for any follow up questions you may have in this issue.
I'm online Daily from 7 AM till late Eastern Time Zone .Thank You ***** Certified Technician
Customer: replied 1 month ago.
Please read and rewrite your last response....It's pretty garbled and doesn't make much sense.
Sorry ,
At this time that is all I know on it ,so I will opt out of your question and open it for other expert so they can help you further on it ,please do not reply back to me since it will lock the question back to me and other experts will not see to help you further .
Thank you .

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?


Customer: replied 1 month ago.
The fuel filter was recently changed. The last oil change I do not know about because the truck was recently purchased, but it is full on the dipstick

Alright. Are you using a scan tool that can read the sensors, or just a code reader?

Customer: replied 1 month ago.
I have a Genysis scan tool

Ok, the next thing to do is check fuel pressure at the fuel filter housing. Do you have a fuel pressure gauge?

Customer: replied 1 month ago.
I will get to it as soon as I can

You'll want to see abou 55 psi at the housing


Customer: replied 1 month ago.
I do not see an access port on the filter 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

Customer: replied 1 month ago.
I used the filter drain pipe to check pressure.....I have exactly 55 psi

Ok perfect. Using your scanner, Monitor the ICP pressure with the key on and the engine off. Does it read 0 psi?

Customer: replied 1 month ago.
I will check that today and let you know....Do you know what ICP stands for?
Injection control pressure. Your truck runs fuel into the injectors and runs high pressure oil on top of the injectors. That high pressure oil system operates a poppet valve in the injector which is used to control the fuel pressure. The p1211 says the injection control pressure cannot be controlled correctly by the computer, so we have either a fuel or ICP (high pressure oil) pressure problem. It looks like the fuel pressure is ok, so now we look at the injection control pressure system.
Customer: replied 1 month ago.
Here are the values.....ICP fluctuating in the 550 psi range / ICP voltage is .90V
With the engine NOT running, correct?
Customer: replied 1 month ago.
Sorry...I didn't read your post thoroughly enough.....With the engine OFF (not running) and switch on the ICP is 0
Customer: replied 1 month ago.
6Bucs...Are you still with me?

Ok perfect and about 550 at idle? Is that on a cold or warm engine?

Customer: replied 1 month ago.
550 on cold 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.

Customer: replied 1 month ago.
ICP @ hot / Idle = 470 ICP @ Hot / Open Throttle = 2000 IPR Percentage Duty Cycle @ Hot / Open Throttle = 19%
Customer: replied 1 month ago.
6Bucs? Are you on vacation?
Customer: replied 1 month ago.
I would really like to get this truck problem solved and behind me....Is there any way we can expedite this interaction and make it move a little more often and/or quicker?

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

Daniel Wilson,
Category: Ford
Satisfied Customers: 5564
Experience: Owner at DJ Wilson
Daniel Wilson and 4 other Ford Specialists are ready to help you

I tried calling. Let me know the best times to reach you EST.

Customer: replied 27 days ago.
I will get into the procedures you suggested on Monday....I will need you to give me some more info on where and how to do the tests....One thing I noticed that I'm wondering about is you are saying the the fuel pressure should be 75-85 psi. If you read the previous contacts, then you know the last expert said it was supposed to be 55 psi, which it was. Which is it? A good time to contact me by phone would be between 10 and 6 M-F

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.


Customer: replied 24 days ago.
My email is***@******.***

Thanks for the update. Did you get the publication I posted in the troubleshooting link?

Customer: replied 24 days ago.
I got the link but it went to a complete manual....Not sure exactly what part of that I need to look at.

Fuel pressure testing and injection control pressure testing for starters.

Customer: replied 24 days ago.
Have you read the codes and past interaction with the other tech....I ask this because some of the specs for the terms you mentioned have already been read and given with a scan tool.
Customer: replied 24 days ago.
I told you before that the fuel pressure is 55 psi and below are the ICP and the IPR values along with the date I originally posted this information19 September 2017 11:47
ICP @ hot / Idle = 470 ICP @ Hot / Open Throttle = 2000 IPR Percentage Duty Cycle @ Hot / Open Throttle = 19%

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.

Customer: replied 24 days ago.
I'm only at the shop until around 6p so you will need to call before that to get me....Sorry, but I'm not seeing these tests in the materials you sent....At some point in time, I heard that Diesels were preferable because maintenance is simple..."If they have fuel and air, they will run".....This seems a far sight more complicated than that.

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.

Customer: replied 24 days ago.
Also...We still haven't dealt with the fuel pressure discrepancy....6Bucs said it was supposed to be 55 psi and it was that exactly....You're saying it should be 75-85 psi....In my opinion, if you are correct, this indicates a problem....Why go any further in testing until we get the FP up....This may well be the problem.

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.

Customer: replied 22 days ago.
Any idea what kind of thread or device I need to apply shop air to the ICP sensor port?....I thought it was standard 1/4 pipe thread...But no, they've got to be contrary and make it something strange and different

Try a rubber tipped blow gun and hold it there firmly

Customer: replied 16 days ago.
I don't know if you were looking for a laugh or just didn't know but a rubber tipped blow gun is definitely not a good idea to apply shop air to the ICP port....It took me a half hour to wipe the oil that blew back off of my body....ha ha....However, I finally made a set up that would work in the ICP port. I applied shop air and didn't hear anything for a few seconds, then I heard something pop and then I heard what sounded like leaking air on the left side. I also decided to check the Control pressure, so I installed the 5000 psi gauge and it was about 1000 with 1.4 volts from the truck at idle. I then applied 12 volts and the pressure went up to over 4000 psi ....
Customer: replied 15 days ago.
Daniel.....Did you get my reply?

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.

Customer: replied 15 days ago.
I'm not sure I'm understanding this correctly, but you said the ICP should be at least 500 psi for the injectors to fire.....According to the scan tool, I have around 700 psi and according to the pressure gauge I installed in the ICP sensor port, I'm over 1000 psi. I'm not disagreeing with your belief that the injector leaks need to be repaired, but it looks to me like we're getting the pressure required to fire the injectors and that is not happening.

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?

Customer: replied 15 days ago.
That message is NOT accurate.....As I said, I'm reading 1000 on the mechanical gauge and around 700 on the scan tool from the ECM, that I presume in reading the sensor.

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...

Customer: replied 15 days ago.
Also, when I did the full throttle test, I only read 2000 psi.....I proved it is capable of 4000 plus with the 12volts to the IPR...I'm not sure what this says or whether it matters but it is.

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

Customer: replied 15 days ago.
I would gladly jump right in and change those injector seals if you or I was 100% sure that's what it was, but to me all things aren't pointing to that. Why am I not seeing 1000 psi on the scan tool @ idle or 4000+ @ open throttle?
Customer: replied 11 days ago.
Daniel? Are you still alive?

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.

Customer: replied 11 days ago.
Are you talking about the external o-rings

Yes the external o rings that seal the injectors on installation.

Customer: replied 10 days ago.
We will change them and let you know the outcome....

Thanks for the update. Let me know

Customer: replied 9 days ago.
I'm in the process of tearing it down to replace the seals and was thinking it would be a good idea to check the injectors while doing this to make sure they are all firing properly. One source said to check the temperature on the manifold while running to see if any of the cylinders are running cold...(Meaning the injector is not firing). I did this but I'm not real sure how accurate it is. It seemed as though the front cylinders ran cold and the rear ran hot. I also saw in the material you sent that the injector connectors can be pulled while the covers are off to see if there is a difference in running, but I'm a little puzzled about this because it seems to me that oil is going to fly everywhere with this high pressure system with the covers off.

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

Customer: replied 5 days ago.
In trying to resolve this issue as quickly and equitably as possible, I'm wanting to cover all bases and possibilities. With that in mind, I took the inter cooler pipes off the other day in process of removing the valve covers. After I removed the pipes, I decided to take the truck for a drive to see what would happen and experienced no difference in performance whatsoever. To me, that would seem to indicate we are getting no boost. This coupled with the fact that three of the four codes set are turbo related would seem to indicate turbo / boost issues. What do you think? What could cause this and/or how can this be checked?

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

Customer: replied 4 days ago.
Could you please rewrite your last reply......Some of it is missing or doesn't make sense

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.