Power Loss Under Hard Acceleration

[garylmoore]

On a warm truck, if I get into the accelerator hard ( about 2200 rpm) the truck will stumble then come right back. When the engine is cold, I get the same problem on less acceleration. If I get it once, the truck is much more prone to get it a second time in the same drive.
When it happens, it is like the fuel has been taken away, but lift pump pressure and rpm do not change. The injection pump seems perfectly fine other than this problem.
Codes are
0234
1689 and1693
0230
0500
This problem has been happening for 2 years, this is the first time I have gotten the boost limit exceeded code. I read in other posts that fuel is cutoff when an over boost occurs and to check the wastegate line and make sure the wastegate is not stuck. Can I manually move the wastegate without removing the turbo? I cannot seem to find anything on the subject except that I need to check it.
The vehicle speed sensor fault only comes up during this particular situation. The sensor was replaced but it persists. It faults at no other time and my cruise control operates fine.
Thanks... Gary

 

[SnoKing]

500 is from spinning rear tires, my 2001.5 with DTT transmission always set that code. The wastegate works against a heavy spring, you might be able to remove the boost hose from the intake and apply some air to it and see if it moves or if the diaphragm is cracked/broken. At 30-35 psi it should be opening. Do you still have the little HY-35(auto transmission)?

 

[garylmoore]

I guess it is possible that I spun the wheels the day before in the rain, but this has happened so much, I bought a new speed sensor and installed it last year. I do not think it was from wheelspin in my case.
The transmission is a 47RE.
I will try putting some air into the WG actuator and see what happens.
Thank you.

 

[JR]

You have a lot of different things popping up there. Is your truck stock? Any programmers? It is a good idea to investigate each issue but the common denominator here could well be a communication issue. Have you checked your running voltage? Improper voltage does goofy things to these trucks. On the lift pump code is your lift pump OEM or aftermarket? If aftermarket thoroughly go through all connections and relays to make sure everything is clean (no corrosion) and tight. Same if it is stock for that matter, and Same with your VP. pull connectors apart and check for corrosion or broken pins. Two of your codes are communication errors - P0230 lift pump current too high/low, P1689 no communication between ECM and VP44. If I remember correctly the ecm is grounded to the block behind the starter. Give that a close look. If initial inspections don't reveal any obvious problems you may have to find someone with a scan tool that can hook up to your OBDII port and read live data while you go for a ride.

 

[garylmoore]

I don't normally check for codes unless the CEL is on, but the speed sensor fault is always there when I have this problem. I had a problem with the cruise failing some time ago and replaced the sensor on the diff, but have not changed the sensor on the transmission and not sure which sensor the fault is based upon.
I also noticed yesterday that the torque converter cycling has made it's first appearance on this truck. I checked for AC voltage some time ago and the alternator was borderline bad. So I bit the bullet and purchased a new alternator from Nations Parts. That should be here tomorrow. All battery cables and batteries are new. I do not think I have cleaned the ECM ground at this point, all others were done when new cabling was installed.
No programmer.
Fass Titanium lift pump.
Otherwise, stock truck.
When the truck defuels, I am hard into the throttle and always gaining speed, it does not do it if I am not into the pedal. The defueling is completely repeatable, mash the pedal and in ten seconds or so the truck will choke. Take the acceleration easy and there is no problem.
I had mentioned above that it happens at lower speeds when cold, then later figured out that was the TC cycling, the rpm drops with TC cycling, they do not drop with the hard acceleration defueling problem.
I have cleaned the connection on the Piston pump. I have not messed with the connections on the Fass but my LP fuel pressure has always shown rock steady on the gauge.
Thanks Gary

 

[JR]

It does sound like a sticky waste gate. Aside from testing it you could verify with a manual boost gauge if you have access to one. One method is to replace an intake bolt with one of these and run a manual gauge in the cab.

https://www.googleadservices.com/pa...BmomfT_k02Z4tnK2xXEMRpuMetnEUChsaAmJsEALw_wcB

 

[garylmoore]

Update on this old thread.. I still have original defueling problem. Removed the turbo\wastegate, actuator stuck, replaced actuator. Turbo body had a crack in it, replaced turbo. Map sensor tested ok. After replacing the actuator and the turbo, overboost codes have gone away, I thought I had it but...

Truck is still defueling at approximately 2000 rpm or under hard acceleration.

Only 2 codes left are the 1689 and 1693, loss of communication to transfer pump. Mechanic checked fuel supply from lift pump, lots of fuel, no air. All grounds have been cleaned, all battery cables replaced with new, new Interstate batteries. Mechanic is checking wiring at this time. Other than the defueling, the injection pump seems just fine, no hard starts no other strange behavior.
Could this have anything to do with the TPS?
Any other suggestions on where to look?
Thanks.. Gary

 

[JR]

P1689 is not about the transfer pump. It is related to the VP44 and more often than not caused by a failure of the fpcm.

Here's some good reference material for you.

This symptom is RARELY caused by an electrical problem with the Injection Pump. It can be a mechanical issue inside the pump caused by WVO or Biodiesel damage or even a blown head gasket. First, be sure that there is no air in the fuel supply and no relevant codes by doing the appropriate tests. If a relevant code exists, like a 336 or 1690, replace the crank sensor first to be sure to eliminate it as the cause of the skip. If you have a 251, 253, 1688 or 1689 code these only pertain to the Injection Pump and are strong indications the electronics in the VP44 are BAD, and that the pump is bad

https://www.bluechipdiesel.com/troubleshooting-quick-reference

 

[SnoKing]

P1689 - No Communication Between ECM & Injection Pump Module

Control board in VP-44 is TU.

 

[garylmoore]

P1689 is not about the transfer pump. It is related to the VP44 and more often than not caused by a failure of the fpcm.

Here's some good reference material for you.
https://www.bluechipdiesel.com/troubleshooting-quick-reference

I am sure the transfer pump is good, pressure has been checked and it holds steady when the problem occurs.
By TPS I am talking about the throttle position sensor ( I should have said APS?), if I may possibly have a dead spot. It seems to repeatedly fall off in the same spot in the RPM range.
I realize I am down to the wiring, the IP or the ECM. I just want to make sure that I do not replace one or both and still have the problem.

 

[garylmoore]

P1689 - No Communication Between ECM & Injection Pump Module

Control board in VP-44 is TU.

I got ya here.. but I need to be sure if it is the IP, or the ecm, the cable between and that it is not in the Apps.

 

[JR]

You mentioned transfer pump, I was just clarifying.

If you are a DIYer and follow the steps on Blue Chips website, you can't go wrong on a diagnosis. They nailed the VP44 system down to a science years ago.
Need to do due diligence, be methodical, and don't hesitate to call them for help if you need. Super friendly people.

 

[garylmoore]

I am sure the transfer pump is good, pressure has been checked and it holds steady when the problem occurs.
By TPS I am talking about the throttle position sensor ( I should have said APPS), if I may possibly have a dead spot. It seems to repeatedly fall off in the same spot in the RPM range.
I realize I am down to the wiring, the IP or the ECM. I just want to make sure that I do not replace one or both and still have the problem.

 

[SnoKing]

You mentioned transfer pump, I was just clarifying.

If you are a DIYer and follow the steps on Blue Chips website, you can't go wrong on a diagnosis. They nailed the VP44 system down to a science years ago.
Need to do due diligence, be methodical, and don't hesitate to call them for help if you need. Super friendly people.

Very good advice from JR, Blue Chips has a very good trouble shooting procedure on their web site.
https://www.bluechipdiesel.com/troubleshooting-1

If the stuff above does not help, then call them.

SnoKing

 

[garylmoore]

I finally solved these problems and there ended up being more than one. For the overboost code, the wastegate was frozen, when the turbo and the wastegate were removed, there was also a crack in the turbo housing, the turbo and wastegate were replaced. That got rid of all the codes except the 1689. I purchased a pump from Thoroughbred Diesel, 2 year warranty at a very reasonable price. That solved the 1689 code. All together about $2900 total including the diagnostics and labor for a local shop. It is a wad of money, but the truck runs great and all codes are gone.
Thoroughbred Diesel and KO Truck and RV in Rockford Illinois did a great job for me. I was going to do the job myself, but a recent move made my garage unavailable.
Thank you for all the good advice.. Gary