Need codes, but my vote is for the IPR or the HPOP pressure sensor on the cylinder head rail.

 

Went to the local stealership and had the codes pulled. What codes? Not a damn one. And as typical, took mechanic for a ride and it we could not duplicate the problem until just as we went into the shop parking lot. Then it kicked so hard, I thought it was going to tear the rear end out.

Without codes, they wanted to do about $700 of test. Screw that idea. I have always been leary of the fuel pump on it since I busted the fuel tank. Damn, my cost on the pump was $300.00. Going to have it installed in the morning. If it is not that, I will change the sensor on the head. It is cheaper than the IPR. That mother cost $300 too.

It has got to be one of the three. I will check the nut in the morning. I did not think about that one. Thanks for that clue.

Well hell, there went my brush bar and Harley Headlamps.

 

Hmmmmmmm, throttle position sensor? You could buy a new one, bolt it in and try it out for a LOT less than $700.00!!!

 

You know for a few hundred dollars you could just buy your own AE if you have a laptop.

Would the TPS make it jerk that hard Dan? I've never had one act up, I just always assumed if it did it would mimmick someone acting crazy with the pedal or not give a response.

Any dash lights come on of flash when it does this Paul? Did you not get any codes, or just not get any important ones? P0603 might indicate a short to ground even though the book will just say it's a KAM error from disconnecting the batteries or needing to clean the terminals.

 

Chris, they did a deep scan with Ford's Diesel scanner. I stood there and watched it go through all of the paces from testing with key off to with it running. There is no codes there.

I did not think we had a TPS, other than the one on the pedal. That though did cross my mind though.

There is only three sensors left after this. I have replaced all of them, including a few solenoids since last summer. I am running out of ideas now. There is no dash light on or flashing. The kick did not even set off the CEL. That is why I am so puzzled about it. Everything points to fuel.

I do have a laptop. Where can I get a program and adapter that would work with it?

 

ITP has the best deal on the AE. AutoEnginuity PC Scan Tool (USB)

The advantage to this is you can monitor and record live data for these different sensors, so even if it does not throw a code, you can look to see if a sensor acts up when the truck does this. For instance you can select ICP pressure, IPR duty cycle %, TPS % and if one of those numbers jumps or drops significantly when the truck does this you can narrow down your search.

I'm not much on auto transmissions, but is there a chance you've got a tranny issue? Does the fluid in there look good and is it full? Engine oil full and clean? Battery connections and grounds all in good shape?

 

I really doubt it now that I think about it. Seems more likely the engine would either run right or idle, but no jerking.
.
Buying AE would be the better option right now.

 

The enine idles just fine. When cold, it responds with the idle up. I also checked with a volt meter on start up when cold. Once it starts, I have a voltage reading of 11.4 until the glow plugs kick off, then it is up to 14.2 to 14.4.

I am having the fuel pump put on it today. If that does not help, I will replace the other two sensors. After that, hell, I don't know.

I did look at the scan web site. Thanks for that. Since I have a good laptop, I will call them. I need to make sure that it will run on Vista.

 

I can tell you that AE does work with Vista. That's what I have on my laptop.

 

I just re-read this entire thread and no mention of checking the IPR.
A sticky valve inside the IPR will make it jerk hard like that because the HPOP oil pressure is uncontrolled.

 

The HPOP is continuously being changed as the engine is running.
It is supplied by the LPOP, then the oil goes through the HPOP to the injectors and from there the oil vents out the side of the injectors to drain back into the sump.
No only way for the oil to get returned to the HPOP is through the LPOP.
So simply changing the oil in the truck will "change" the oil in the HPOP.
You drain the reservior to get out that last drop of old stuff, but it won't be any dirtier than what was in the pan.

 

Dang Paul, haven't you spent enough on that truck lately? I'm pretty sure any thing with the ICP or IPR causing surging rough running will at least show that 1211 code if not more. That's a simple above/below desired pressure code and should trip anytime more or less oil pressure is called for, but not met.
If the fuel pump was failing, I would think you would notice it more when accelerating rather than cruising. I don't know if a VSS would cause that with out setting a code, doubt it. Same goes with a transmission slipping. The surging then stumbling engine sure sounds like a fuel supply issue. Wonder if air is getting in the fuel supply enough to cause the stumbles? Also, what does your dash gauges do when it stumbles? If they go dead, you may have an electrical problem causing the stumbling.

 

Yeah Barry, I sure have. Just got it back. I will find out that a surge/stumble with no codes is caused by the low pressure fuel pump. I just pulled that mighty handle and flushed another $400.00 at her. Truck is getting as bad as that daughter of mine, always with that hand out.

I have not noticed anything else going on. I just get in a low rpm cruise and the stumble, then surge, then stumble starts. Also, there is no power at all. That 7.3 should sink me in the seat when i nail it in 4th gear. 4th is like overdrive, nothing.

 

Update:

Well, I guess I should have did what Mark suggested in December. He told me to swap out the fuel pump. His reason, I busted the fuel tank back in January and there was a possibility that the pump had sucked trash, plastic or the junk from the road into it. I did not do his suggestion. I did not see anything wrong with the pickup tube when I swapped the tank.

I called back to the shop. They dropped my tank before putting the new pump on as they wanted to flush the lines. My mechanic told me that there was no trash in the line but the drop tube had a split above the filter. They replaced the pickup unit, then installed the new pump. He also told me that he dumped a lot of trash out of the pump.

Now, the first drive. Well, the WOW FACTOR is not there yet, but I know the fuel system is full of air. I ran it through several 40 mph zone in O/D with the rpm at the 1700 range, moving it up and down from 1500 to 1900, no stumple, no surge. It does seem to respond better. Actually it will break the rear tires loose on a wet road in third gear if you punch it from about 40. So maybe Mark was right. The next few days will tell.

If it is fixed, next job is to drill the manafold, drill the turbo housing and install the temp and vacuum gauge and put my BD chip back in.

 

Man I hope that fixes you up.