Smoke, smoke and more smoke - no power, limp mode?, 45km max, 1500rpm max

[Turbine Doc]

Cat = soot trap, scrap it ASAP if U can Diesels don't get hot enough like a gasser for a catalyst core to burnoff the residual hydrocarbons post combustion, add in a bad injector or blowby or bad CDR dumping excessive oil especially in a S truck recipe for plugged cat.

I've been sans cat since 2000 my truck even at 2yrs old then & 37K miles was nearly plugged solid with crud, so get rid of the cat if U can.

If it must be there for appearance sake/inspections core it out then run a pipe thru the shell for best flow with the gutted shell around the pipe and plumb rest of exhaust to that, best however; especailly if going for max power at some point down the line is upgrade to a 4" replacement system with mandrel bent turbo downpipe and crossover pipe.

 

[Turbine Doc]

I am so glad I dont have a turbo!!!! As a newbie its all I can handle with the grounds, grounds, grounds, its all about them grounds!!!! Have I mentioned that woodchuck chuckin wood lately????

Night & day difference with that turbo on it, go with a non WG turbo like ATT and puter won't have a clue it's there but you will as it will gain 50+ Hp on that puppy.

 

[rooski]

Boy you are new at this

Need to spend some time in the TRL for details, quick primer though low power & lots of smoke = low boost, gauges are the friend here EGT & Boost @ minimum.

For quick test since you say 26" Hg from vac pump, plumb direct to the WG actuator on turbo and see if that holds turbo shut on test drive, yes you'll code but smoke should clear and power should be back toi a point, you'll probably limit to max fuel of 50 mm in limp mode provided you have healthy lift pump delivery. Mitey vac test WG actuator to make sure the diaphragm is working bad bellows there wont keep the WG shut under load but may allow it to stay shut @ idle power, ergo the need for gauges so you will know what boost is when driving.

WG should always be kept closed that is how boost is made with the GM turbo, when less boost is called for vac is bled off so less drive energy ported to the turbo slowing it for less boost, again deep detail for function is in the TRL.

PCM vs APP position vs IP & engine sensor feedback used to control fuel delivery for the 6.5, it is still a hydromechanical IP but puter inputs to fuel solenoid/PCM to command the delivery of IP to injectors which a wholly mechanical. 100K miles on injectors is "normal" life recommended could be a worn injector or 2 but lets confirm boost and lift pump delivery is where it needs to be.

Lift pump from tank to filter mgr to IP to injector is simple fuel path, unused fuel returned to tank, lift can purr fine but still be weak in total delivery at load (details how to check in TRL)

Gnds-Gnds-Gnds lifeblood of the electrical puter controlled 6.5 system again TRL has great info on that account, I know as I put it there

TRL is here http://www.thetruckstop.us/forum/showthread.php?13960-Sticky-6.2-and-6.5-Technical-Library also at top of main 6.5 forum

Hey, thanks... I understand the boost requirements and action. That's pretty straight forward. I have wired closed the wastegate, turbo spins over fine, yet black smoke like crazy and still no power. I fully expected to get the results you speak of but did not. basically there was no change.

I also understand the fuel path, but have yet to pressure check the LP. It appears good at simple flow test by opening the water valve and opening the bleed on filter top, but I only tested both during running, so fuel could be pulled along by IP somewhat. I do not have a way to check fuel pressure so \i will test without engine running to see if \i still get good flow.

I will be installing a boost guage this weekend as well.

 

[NVW]

When wiring the WG shut it has to be extremely tight as any movement will drop boost.

 

[rooski]

When wiring the WG shut it has to be extremely tight as any movement will drop boost.

you bet. stiff haywire wrapped a few times round to ensure it was like being bolted or welded in place.

 

[ak diesel driver]

might be carboned up and not sealing properly

 

[Turbine Doc]

X2 only takes a little cracked open of the WG on the GM-X turbos to lose boost which is why the prompt to straight plumb vac to the WGA on turbo, as full vac 100% closure permitting the WG flapper in turbo is fully seating

 

[rooski]

X2 only takes a little cracked open of the WG on the GM-X turbos to lose boost which is why the prompt to straight plumb vac to the WGA on turbo, as full vac 100% closure permitting the WG flapper in turbo is fully seating

makes sense. I will try that.
also cat gets burned this weekend via plasma cutter
I'm installing boost guage too.

Best way to delete egr ??? any suggestion to override effects on cpu? i dont want it thinking something is wrong if it cant see the egr active.

no worries here on emission testing. the more we can put back in the ground will keep the economy going here in 'oil'-berta.


btw, all grounds have been r&r'd with a good scrub shine to ensure no funky milli-x errors with the cpu

 

[Turbine Doc]

Well best way is wholly going F intake with reflash to ignore the missing S (EGR) stuff.

In the interim until you can go there, put a shim under the EGR valve .050" thick or so too thin and it will blow out, learned this myself back in the day when I was still contending with S stuff.

In OBD-II's PCM does not monitor EGR valve position it monitors the changes in vac system pressure as applied to the EGR valve diaphragm via the firewall baro sensor which serves 2 function monitor for EGR purposes & baro pressure @ startup, which is why one can't just plug off vac lines on OBD-II S engines PCM has to see the changes to not set EGR system codes, blanking off the valve allows it to travel but not "pass gas" :O EGR gas that is .

Ahh one more thought S upper to lower intake has a crush gasket in center IIRC I have a photo of it in TRL pictures thread, if that is bad it will allow for full time flow of EGR gas and also smoke & low power you describe,>

Look in part point in TRL for the p/n also you can search for phrase "mystery gasket" and should be able to find it.

Still need to TS vac/boost system but if all is good there pull 6 bolts from upper and check condition of the crush gasket, mine was rusted & leaking back in the day.

Another quick power adder for the S trucks is to find a F PCM from truck graveyard with same config as you, trans, 2wd/4wd, same year if possible, 97+ years are theft deterrent PCM so will need to be a 98+ model & relearn the TD code on yours 97 may or may not work, also same axle gear ratio, S to F PCM swap will get rid of EGR codes as they don't have that junk, also will up max fuel rate from 56mm to 63mm reflash as I noted before reflash is way to go as all your trucks specifics are programmed in and 80+mm max fuel can be requested then from the IP.

 

[rooski]

Well best way is wholly going F intake with reflash to ignore the missing S (EGR) stuff.

In the interim until you can go there, put a shim under the EGR valve .050" thick or so too thin and it will blow out, learned this myself back in the day when I was still contending with S stuff.

In OBD-II's PCM does not monitor EGR valve position it monitors the changes in vac system pressure as applied to the EGR valve diaphragm via the firewall baro sensor which serves 2 function monitor for EGR purposes & baro pressure @ startup, which is why one can't just plug off vac lines on OBD-II S engines PCM has to see the changes to not set EGR system codes, blanking off the valve allows it to travel but not "pass gas" :O EGR gas that is .

Ahh one more thought S upper to lower intake has a crush gasket in center IIRC I have a photo of it in TRL pictures thread, if that is bad it will allow for full time flow of EGR gas and also smoke & low power you describe,>

Look in part point in TRL for the p/n also you can search for phrase "mystery gasket" and should be able to find it.

Still need to TS vac/boost system but if all is good there pull 6 bolts from upper and check condition of the crush gasket, mine was rusted & leaking back in the day.

Another quick power adder for the S trucks is to find a F PCM from truck graveyard with same config as you, trans, 2wd/4wd, same year if possible, 97+ years are theft deterrent PCM so will need to be a 98+ model & relearn the TD code on yours 97 may or may not work, also same axle gear ratio, S to F PCM swap will get rid of EGR codes as they don't have that junk, also will up max fuel rate from 56mm to 63mm reflash as I noted before reflash is way to go as all your trucks specifics are programmed in and 80+mm max fuel can be requested then from the IP.

oK, I know the mystery gasket location. Perhaps this is why I get the bucking when egr vac line is connected as well (?)

what does IIRC stand for. it is not listed in the TRL.

Also, reflashing the F truck PCM... dealer does this or what?

 

[Turbine Doc]

Acronyms list in TRL should have it IIRC = If I Remember Correctly

For reflashes dealer won't do it most times as you would be violation of the config taking EGR to non EGR sumthing most dealers won't do, also they would limit to stock performance levels. Several companines do reflashes I'm partial to the Heath reflash myself from Heath Diesel. Westers in Canada closest to you if buying from South of the border make sure they ship via US parcel post or you'll wind up with brokerage fees that can really up the cost.

 

[rooski]

well, changed the mystery gasket tonight and now get limited rpm even when not in gear. seems to build pressure inside engine to a point and holds itself back from revving up all the way. i can get it to 2k rpm, lots and lots of smoke.
worse on power in gear than ever.
seems the gasket fixed something but left me with a more directed issue. sometimes worse is better??? narrowing it down possibly.
any thoughts???


found vac pot on turbo is leaking a bit
cutting out cat in the morning, installing boost guage in the morning, building tm in the afternoon to use til i get new vac pot. might leave tm on if i like it.
did not delete egr with plate but unhooked vac to see. with it hooked up i still get bucking but i think that has a bit to do with poor vac pot and possibly poor fuel delivery?? LP seems fine but may as well buy one of those too for peace of mind.

 

[rooski]

thanks for that. found in trl

looked at heath's pcm. not a bad deal to get away from egr system. keep it simple, right? get rid of the junk !
wanted to stay factory but factory seems to be the cause of alot of grief for me and others.

 

[Brooklyn Tow]

I am not interested in changing to a mechanical wastegate or anything else that takes away from factory setup, so please no responses of that nature.


Thanks in advance for your help !
:skep:

get rid of the junk !wanted to stay factory but factory seems to be the cause of alot of grief for me and others.

Quick learner..........:hello:

And WELCOME to DTR/TTS

 

[rooski]

Quick learner..........:hello:

And WELCOME to DTR/TTS

I guess I just think engineers have some knowledge. Also though, the govt boys tend to make them do things that turn out to be STUPID.

This is a good site. Lots of good guidance !

I am a believer...:thumbsup:

 

[Brooklyn Tow]

Collectively, there is not a better place for Good people (Little 6.5 family we are), Info, Diagnosis and sheer foward thinking, when it comes to the 6.5 TD.

Member Slim Shady is responsible for the creation of the A Team Turbo (ATT)......Where the GMx left off the ATT is just getting started.....with many benefits to go along with it than just boost.

You are in the right place!

 

[rooski]

Acronyms list in TRL should have it IIRC = If I Remember Correctly

For reflashes dealer won't do it most times as you would be violation of the config taking EGR to non EGR sumthing most dealers won't do, also they would limit to stock performance levels. Several companines do reflashes I'm partial to the Heath reflash myself from Heath Diesel. Westers in Canada closest to you if buying from South of the border make sure they ship via US parcel post or you'll wind up with brokerage fees that can really up the cost.

Just wanted to let you know, I cut out the cat, made a turbomaster from the original vac pot (using instructions from the post), and installed a boost guage.

RESULTS:
WOW, cat was plugged solid. It had about 1/4 to 1/2 inch of hard baked soot covering the insert. I had to chip it away to se the insert !

Can hear the Turbo whine very nicely now !

Boost pressure easily set up to max at 12 psi

Truck runs and drives absolutely fantastic now !

Tons of power like it's suppose to have with very little smoke even when you throw the hammer down hard.


Thanks to you and everyone else who chimed in to help out a newcomer.


Next step, delete the egr system. Vac pump works so egr currently hooked up as is supposed to be with wastegate vac line plugged off.

Maybe drive it a bit to clean it out further and get some fun out of it, then look into some other good mods.

Very happy. Bought the truck thinking I might get lucky with the issue being small, which in fact it was after all. Got a steal of a deal. $1500

:agreed:

 

[Chief915]

Great news..... Glad you've got it fixed.

Like BrooklynTow said, everyone here will help you out with whatever you need.

Don't be afraid to ask questions.

 

[Brooklyn Tow]

Great news..... Glad you've got it fixed.

Like BrooklynTow said, everyone here will help you out with whatever you need.

Don't be afraid to ask questions.

Or make a few NON OEM modifications......VERY Glad you found and eliminated your issue, you must feel like you won the lottery.....Gotta love when a plan comes together!

Enjoy Rooski.....If your not addicted yet, 1 or 2 more Mods should do the trick....You'll be a full blown Junkie in no time!:thumbsup::hihi::agreed::rof::hello:

 

[Turbine Doc]

Well GM screwed the pooch on many things on these limiting the power & durability, that and beancounters wanting to save some $$$ vs making best truck they could have made. Glad you have got it to run better now get ready for some non OEM mods. More collective been there done that & still doing it 6.2/6.5 know-how than any otherplace on the web it right here.