On the road and having some issues

[superstroked]

I am up in red river , NM at about 8500ft and I am having some issues that are all related I am sure. I have been running the spartan 275 tune which is an EGR off tune. At idle, the truck is not making boost like normal(usually about 3.o on the Dasdaq, now only like .4). Also, the truck will not make more than 25 lbs of boost at wot. From an idle taking off, it has some excessive rattle until it gets a little boost. Yesterday, it threw a turbo duty cycle code of some sort and like a dummy I just cleared it as I was not noticing any issues at the time so, I don't know what the code number was. I checked the boots on the intercooler and they were fine. Could this be an EGR issue? is it a VGT issue? Also, I have switched the tune back to the 125 tune which should be an EGR tune and when monitoring EGR, it never changes off of 0% even when it is fully warmed up. If you have had the problem or have an idea of what it could be, I would appreciate the help.

 

[Dzchey21]

Whats your vgt duty cycle when going down the road?

 

[superstroked]

Whats your vgt duty cycle when going down the road?

I will take it for a ride in a bit and report back...at idle it is like 95.00006 or something like that...I will let you know

 

[Dzchey21]

yup thats normal, just trying to see if you have a back pressure problem or something, might as well monitor back pressure too, almost sounds to me like the egr valve is stuck open some how

 

[superstroked]

The vgt drops steadily as boost builds and looks to be working fine...The EGR is what I am thinking too. Is there a way to manually close the egr valve or to get it unstuck at all? I mean, it is driveable like this but it sucks

 

[Dzchey21]

Not that i know of the best thing would be to go get a gasket from a local dealer and have a shop see if they can cut you a sheetmetal block off plate that is similar to the gasket, that would be the quick/easy way to do it.

You could try and take it off and clean it but i honestly am not that familiar with them, i just took it off and thru it in a tool box for storage, I could send you this one but it wouldnt be till tuesday till you got it...

 

[superstroked]

Is the EGR right on top in the front of the motor where the up pipe from the intercooler comes in. It looks like two torque screws hold it on?\

 

[Dzchey21]

thats the egr/mixer valve assembly


What you need to block off is where the upper egr cooler hooks into that, should be two bolts, or two nuts im not sure. looks like a little peice of flex pipe that hooks into it, wish i had some pictures to show you.

 

[superstroked]

I will check it out

 

[Dzchey21]

take a pic and post it or text it to me if you have to, ill give you my number if you need it

 

[superstroked]

Is the valve mix assembly what would go bad and and get stuck? I found what you were talking about, looks like 2-12mm nuts right? Did you just put the plate in the middle with two gaskets and bolt back on?

 

[Dzchey21]

yes thats basically the egr valve, that head that sit on the intake where the intercooler pipe is basically the mixer area for the exhaust gas to combine with the fresh air. so, basically you could be pushing boost back into the exhaust or the intake air is so diluted with hot egr gas that its not making boost, im not really sure which would happen first, probably depends on overall back pressure and overall boost, but you get where im going with it.

 

[BFT]

Do you need the plate that goes from the vertical cooler to the intake elbow? If so I might have my old one if you want.

Is your manifold gauge pressure (PSI) or boost reading .4 or up? Does it read negative when accelerating? If so then your EBP (exhaust back pressure sensor might be toast.

If not, then your EGRTA sensor, located on passenger side up pipe, is probably toast. It's pretty easy to do. I did mine in less then 1hr and on the road. A good way to see if this sensor is going bad is if your pyro gauge on your DD is acting wierd.

 

[superstroked]

MGP:I have seen it read negative .1 at idle only. Once accelerating, it is fine.
EGTRA: I have replaced the up-pipe sensor already, that doesn't seem to be an issue here because even on the 125 tune, the temps will get up to around 1500. I am almost 100% positive that the issue is with the EGR.

 

[Gearhead]

Are you sure it isn't just the altitude causing the MAP offset?

 

[superstroked]

Are you sure it isn't just the altitude causing the MAP offset?

I have thought the same thing but, have never had the truck up this high. The one thing that makes me thinking that it is the EGR is that it stays at 0% at all times and does not cycle at all when monitoring on the dasdaq.

 

[Gearhead]

Can you monitor EGR cooler outlet temp? If it isn't getting very hot then you aren't flowing any EGR and your valve is indeed closed.

 

[superstroked]

Can you monitor EGR cooler outlet temp? If it isn't getting very hot then you aren't flowing any EGR and your valve is indeed closed.

I will check and see

 

[superstroked]

I am starting to think it just may be the 9500 altitude....I will report back after I get home but, the check engine light has not come back on and I actually got some egr movement yesterday. I was monitoring actual and commanded EGR and they were fluid.

 

[jdgleason]

Its possible.... Ive been well above 9500 with no issue tho...