No power and won't make boost unless in high gear and over 2000 RPM

[JHawk]

I drove it home and parked it. Restarted later and it came up with a low turbo boost code. This was about 2 weeks ago. Reset the code and has never returned. With my smarty on it, it will fog black smoke. Took the smarty program out and put back to stock. Idles fine, but won't even spin the tires. Revs slow too. Running down road, high EGTs just trying to get it up to speed limit. Then after it goes over 2k to 2200, it will make 28 pounds of boost and go. Right now I have my Edge hooked up so the gauges work. Took intake hose off and turbo is spinning. It seems fine checking for play and spins freely by hand. I also put new fuel filters in it about 2000 miles ago.

Sure acts like an electronic problem to just start like that.

Any suggestions?

 

[cerberusiam]

What year truck and particlurs about it? Trans, miles, last filter changes, etc?

Check air and fuel filters, change them if there is any doubt.

 

[JHawk]

2006 5. 9 6 speed

all filters changed and checked. Ran fine when parked. Started back up 15 min later and then trouble found.

 

[cerberusiam]

What transmission?

Have you put a good code reader on it to see if there is any thing there?

Just as a test, disconnect both batteries. Take a pair of jumpr cables and tie ONLY the GROUND cables together and let it sit for 30 minutes to completely discharge any internal memory store. Essentially, reboot the ECU and see if it makes a difference.

 

[Motorhead]

What transmission?

Looks like he has a G56

 

[JHawk]

yes, G56.

That makes no sense. Tie the ground cables together that are already connected on the truck by battery cable???

 

[JHawk]

do you mean tie the positive cables together for reboot?

 

[JR]

Not sure how your checking your codes but sometimes doing the key trick doesnt always reveal the problem you may want to have it checked with a good scan tool. Codes make troubleshooting a little easier to narrow the search down. Your symptoms sound like a definite map sensor issue, except the part where it takes off and makes power at high rpm. I have seen a few bad injection pumps that had a dead spot in it and would make no power until above a certain rpm. Check all power and ground connections. Make certain BOTH batteries are maintaining proper voltage, improper voltage does wierd things to these trucks. Check your plug connection on your vp to make sure its clean and tight. If everythings fine up to that point, since you originally had a low boost code I would eliminate the possibility of a map sensor issue. I dont know if your familiar with Chips website but here is a link. It would be beneficial to read the entire page but most of the way down he talks about diagnosing a faulty map sensor/signal.

http://m. bluechipdiesel.com/site/vp44diagnostichelp.html







Ok, scratch that whole post. . I was just in the 2nd gen forum, somehow got into the 3rd gen without realizing it. Oops.

 

[cerberusiam]

No, ground cables. The ground cables at each battery are already grounded to the chassis. Tying them together completes the circuit and drains the power out of any capacitors or volatile memory areas in the computers.

The positive cables feed the power and are not grounded, connecting them will do nothing. Just remove the positive cables from the batteries and make sure they don't touch the posts.

Check your plug connection on your vp to make sure its clean and tight.

Your in the 3rd gen forum talking about an 06, don't think a VP is on the parts list. The part about MAP sensor problems does cross into the CR's though. That and an FCA, a messed up ECU, a bad fan clutch among other things will cause the same symptoms.

And, on an 06 the key trick does not work reliably either. Needs a good scanner to check for sure.

 

[JHawk]

Let it sit all day with the positive cables off and the negative cables together with jumper cables. Still nothing...

I am checking the codes with a scanner. Also, my Edge system detects codes and erases them too. I unplugged the fan and got 2 codes. Hooked it back up and erased the codes. That was the only codes in the system. Now there are now.

 

[Cosmo]

Can we get an admin to delete the P. O. S. filter? Thanks...


I've never heard of hooking the negative p0sts together. That seems silly. I have heard of disconnecting the p0sitive cables and touching them to ground, though.


Is your wastegate stuck open? Intake boot torn/loose?

 

[JHawk]

I thought the same thing with the wastegate. Not to say that something isn't holding it open some. I thing it does move under high RPM. It has been a while since I checked it. This is on ongoing fix. Good thing I have another vehicle to drive. I am about to the point of pulling the turbo off and checking it out.

 

[cerberusiam]

It makes 28 lbs of boost at times, WG is not stuck shut or open. WG is electronically controlled but can be bypassed by crimping the boost reference line shut. Try pulling and cleaning the MAP sensor or replacing it as another test. They will intermitently hang in a range and not code while totally messing up the fueling curves.

 

[Prairie Dog]

Can we get an admin to delete the P. O. S. filter? Thanks...

X2. Who ever did this went way overboard or just doesn't know what they're doing.

 

[LNaugle]

Unplug the edge and try driving it. Just putting it to zero won't help.

 

[JHawk]

I have taken everything off and put it back to stock. That is even worse. Will not run past 1500. Sounds like it is in limp mode. Checked wastegate and it is free. Even put vise grips on the hose. I swapped the map sensor from another truck.

I am thinking that it has a bad ECM. Can't swap the ECM from the other truck with the VIN coding they have. I know because I tried it...

 

[cerberusiam]

It is an 06 and some of them had issues with the ECM's. Have you had a chance to check rail pressure yet? If it won't rev stock it is possible something is causing low rail pressure and the ECU cannot compensate correctly.

 

[JHawk]

No I haven't. But, when I put my smarty on it it won't hardly rev and blows tons of black smoke. Smells rich. Acts like pump timing is off.

How do I check the rail pressure?

 

[cerberusiam]

Sounds like the injection timing is off on it. Low rail pressure will cause it to do that, the ECU extends event to try to compensate and you get too much fuel late in the combustion cycle.

You need a gauge or a scanner to read rail pressure. A scanner will use the OE rail pressure sensor which may be bad. An afternarket gauge will use its own sensor and will tell you if the stock sensor is bad. Might wan tto check the PRV and see if it is popped and leaking badly also.

 

[JHawk]

What is PRV?

Where do you hook a gauge up to check pressure?