Notices
Tuning, Diagnostics, Electronics, and Wiring HP Tuners | EFILive | Hand Held Programmers | Stand Alone PCM's | Electronics | Wiring Diagrams

Need EXPERIENCED opinion on Fuel Issue.

Thread Tools
 
Search this Thread
 
Old 08-07-2011, 10:06 PM
  #11  
TECH Fanatic
 
Suburbazine's Avatar
 
Join Date: Feb 2009
Location: Baton Rouge, LA
Posts: 1,635
Likes: 0
Received 1 Like on 1 Post
Default

Originally Posted by 1quikzz
Hey guys, so I have a 2001 Sierra ( see sig) Engine is as follows...

2003 6.0L LQ4
Comp 222/224 cam (LS6 Springs)
Ported/Polshed/milled .015 Heads
Shorty headers
8.1 injectors

I'm have a issue after the truck was Professionally tuned, with it running rough, stalls/sputters when hot, a/c on kills engine. My tuner is thinking its an issue with fuel vaporization in the rail, possibly because I'm running the 4.8 return style intake as opposed to the LQ4 returnless style? Anyone experienced this? or something similar? Is this a tuning issue or a hardware issue. Its driving me nuts, because otherwise the truck runs so strong.

Any insight?

Thanks.
The voice of experience here, check your spark plugs. I had the same issues on my engine and the tuner and I spent HOURS tuning it trying to figure out why it died at idle under any load and ran lean and stumbled on accel, yet ran just fine at higher RPM. I replaced all the injectors, the fuel rail, the timing chain, the O2's. Last ditch effort, I changed the perfectly good plugs. I was using Bosch Fusion +4's, put in a set of A/C Delco plugs and off she went without a hiccup.

That reminds me, I have a free set of Bosch Fusion +4's for a GM 5.3 for anyone that wants them.

Last edited by Suburbazine; 08-07-2011 at 10:11 PM.
Old 08-07-2011, 10:56 PM
  #12  
Teching In
Thread Starter
 
1quikzz's Avatar
 
Join Date: Feb 2009
Location: Bowmanville, Ontario
Posts: 36
Likes: 0
Received 0 Likes on 0 Posts
Default

Would running EGR on it cause these issues by chance? maybe I should delete it
Old 08-07-2011, 10:56 PM
  #13  
TECH Fanatic
 
Suburbazine's Avatar
 
Join Date: Feb 2009
Location: Baton Rouge, LA
Posts: 1,635
Likes: 0
Received 1 Like on 1 Post
Default

Originally Posted by 1quikzz
Would running EGR on it cause these issues by chance? maybe I should delete it
I doubt it but you never know.
Old 08-23-2011, 09:42 PM
  #14  
Teching In
Thread Starter
 
1quikzz's Avatar
 
Join Date: Feb 2009
Location: Bowmanville, Ontario
Posts: 36
Likes: 0
Received 0 Likes on 0 Posts
Default

Tried deleteing the EGR no Change, any one have personal experience with the xr 275hr. my idle is set to 900 rpm and seems to high? the thing runs like complete **** once its hot, Im sure its a tuning issue, but I dont know how I can verify that. I feel like it should run so much smoother than it does.
Old 08-23-2011, 09:50 PM
  #15  
TECH Fanatic
iTrader: (11)
 
sprayedenali's Avatar
 
Join Date: Dec 2009
Location: Birmingham, AL
Posts: 1,573
Likes: 0
Received 0 Likes on 0 Posts
Default

not the fuel rails at all........
Old 08-23-2011, 10:00 PM
  #16  
TECH Regular
 
blackcash's Avatar
 
Join Date: Aug 2008
Location: Ontario, Canada
Posts: 400
Received 0 Likes on 0 Posts
Default

Tuners blame mechanical issues. Mechanics blame tune issues. I'd start looking for vacuum leaks, ignition system faults then if if you find no issues there, it's the tune.

EDIT - Just seen your from my neck of the woods. That's the problem, I don't know of a single reputable competent tuner around. And the mediocre at best guys charge north of $500. A ******* joke.

Last edited by blackcash; 08-23-2011 at 10:06 PM.
Old 08-24-2011, 09:50 PM
  #17  
Teching In
Thread Starter
 
1quikzz's Avatar
 
Join Date: Feb 2009
Location: Bowmanville, Ontario
Posts: 36
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by blackcash
Tuners blame mechanical issues. Mechanics blame tune issues. I'd start looking for vacuum leaks, ignition system faults then if if you find no issues there, it's the tune.

EDIT - Just seen your from my neck of the woods. That's the problem, I don't know of a single reputable competent tuner around. And the mediocre at best guys charge north of $500. A ******* joke.
Where abouts you located. I'm a GM Tech, so I know for sure its nothing mechanical, I've done every ounce of work to this thing myself aside from the tune.

Its to the point where I want to give him one last chance to get it done right, or ask for my money back and go with someone state side.
Old 08-24-2011, 11:28 PM
  #18  
TECH Resident
iTrader: (8)
 
02'Z71ONDUBZ''s Avatar
 
Join Date: Feb 2009
Location: Tahlequah/Norman, OK
Posts: 797
Likes: 0
Received 0 Likes on 0 Posts
Default

Have him email you a copy of the tune and a log, post it here and someone will be able to diagnose the issue. Sounds like the issue starts once it goes into closed loop fueling. Have you checked your trims to see if your o2's are working properly?
Old 08-25-2011, 12:09 AM
  #19  
TECH Junkie
iTrader: (9)
 
Gadgetized's Avatar
 
Join Date: Jan 2010
Location: Rochester, NY
Posts: 3,095
Likes: 0
Received 3 Likes on 3 Posts
Default

Did it ever run properly after the tune? Who tuned it?
Old 08-25-2011, 12:59 AM
  #20  
TECH Senior Member
iTrader: (27)
 
GMCtrk's Avatar
 
Join Date: Jul 2004
Location: Dallas
Posts: 12,275
Received 17 Likes on 17 Posts
Default

I'd start by checking your fuel pressure on the rail at idle and while driving. Has the fuel pump ever been changed?

Secondly, a cam that small in a 6.0 should not be hard to tune at all, and it should idle quite smoothly around 650 rpm.


Quick Reply: Need EXPERIENCED opinion on Fuel Issue.



All times are GMT -5. The time now is 12:55 PM.