Results 1 to 11 of 11
Thread: Symptoms...
-
02-03-2006, 02:05 PM #1
- Join Date
- Aug 2005
- Location
- Thornton, CO
- Posts
- 23,773
Red Tint Jewelcoat- 2008 Trailblazer SS
Symptoms...
New 402 iron block
Patriot Stage III LS6 heads
TSP Giant cam --- 248/254 629/622 113
FAST LSx 90/90
Morel lifters, stock rockers
Car runs.
Backfires at idle.
Hesitates terribly in lower RPM's.
Not a strong as it should be, but runs smooth above 3500 RPM's.
Lower RPM's...it has shot fire when it hesitates.
Replaced O2's, cleaned MAF, reset computer. Same issues.
New problem....stainless headers started glowing after about 3 minutes at 1300 RPM's.
Ideas??
-
02-03-2006, 02:40 PM #2
- Join Date
- Aug 2005
- Location
- Aurora Colorado
- Age
- 60
- Posts
- 302
Sounds like a timing problem, have you done your full blown tune?
If your headers are glowing I would say it is deffentaly a timing problem.
-
02-03-2006, 02:44 PM #3
- Join Date
- Nov 2005
- Location
- Port St. John, FL
- Posts
- 530
Red & Dk Gray- 2002 WS6, '08 G8 GT
Exhaust or Intake Backfire?
Black Sooty exhaust?
How is the idle?, other than the lope of that huge cam?
Lower RPM's...it has shot fire when it hesitates
Do you have an off idle stumble when you get on the gas? Late Timing
SES codes?
What's your fuel pressure at idle?
Glowing headers? Excessive heat, indicates fuel burning in headers.
An rich condition with late ignition timing, so far without more info??
Sounds like a bad tune;
Late ignition timing,
Very rich.
or
Crank Sensor bad or not properly positioned, hooked up
Stupid Question I have to ask??? You did get it tuned after you put he engine in right?
-
02-03-2006, 03:11 PM #4
- Join Date
- Aug 2005
- Location
- Thornton, CO
- Posts
- 23,773
Red Tint Jewelcoat- 2008 Trailblazer SS
There is a base tune on it. Done by a shop owner that knows his stuff.
SES light is on...not sure which code right now. I had reset the computer.
The only one I had seen previous was P0300. Expecting that one though.
What about WAY lean....would that cause red hot headers and all the stumbling?
I believe I may have located a large vacuum leak....I don't think my intake is sitting down on the heads all the way. I messed up on the install of the valley cover bolts. I put the stock LS1 ones back on.
Gonna pull the intake off tomorrow and hope to god it isn't cracked.
Backfire is exhaust.
Hasn't ran long enough to determine if the exhaust is sooty...
Idle seems okay....does kill itself off sometimes though.
Crank sensor....that would have thrown a code if it wasn't learned right?
Probably gonna do the relearn anyways.2008 Trailblazer SS
Yank PTB3600, Kooks 1 7/8" LT's, 4" intake, E-fans, Magnaflow, Sonnax kit, tranny cooler, tune.
Lowered, HID's, tinted.
1999 Pontiac Trans Am WS.6 #1747 SOLD
531.1 RWHP 481.3 FT/Pounds all motor.
-
02-03-2006, 04:02 PM #5
- Join Date
- Nov 2005
- Location
- Port St. John, FL
- Posts
- 530
Red & Dk Gray- 2002 WS6, '08 G8 GT
What about WAY lean....would that cause red hot headers and all the stumbling
#7 is about the Glowing Headers, I especially like #8! I've always been reluctant to recommend a very aggressive Cam, and/or monster heads for anything less than all out racing.
-
02-03-2006, 04:12 PM #6
- Join Date
- Aug 2005
- Location
- Thornton, CO
- Posts
- 23,773
Red Tint Jewelcoat- 2008 Trailblazer SS
Good read.
Thanks!
-
02-03-2006, 05:10 PM #7Originally Posted by RainMan
-
02-04-2006, 05:29 AM #8Originally Posted by Mr. Luos
Originally Posted by Mr. Luos
Edit: SpellingLast edited by Street Lethal; 02-04-2006 at 05:31 AM.
-
02-04-2006, 06:41 AM #9
- Join Date
- Aug 2005
- Location
- Thornton, CO
- Posts
- 23,773
Red Tint Jewelcoat- 2008 Trailblazer SS
Originally Posted by Street Lethal
I have the stock LS1 valley cover bolts on there.
Going to swap those out today and see if that helps.
Talking with the shop that built the motor yesterday, and he seemed to think it was vacuum related. He started asking my some questions...and the valley cover bolts was one of them.
-
02-04-2006, 07:16 AM #10Originally Posted by Mr. Luos
BTW, that's one hell of a cam you selected. Do you know the tuner well? Credible?
-
02-04-2006, 07:26 AM #11
- Join Date
- Aug 2005
- Location
- Thornton, CO
- Posts
- 23,773
Red Tint Jewelcoat- 2008 Trailblazer SS
Yes he is. He has been tuning some of the stronger cars in Colorado.
I planned on getting out there today and checking on a couple little things. Plugs, the possible vacuum leak, etc....
The shop that built the motor seemed to think it was going way lean. But it acts way rich.
I really need to just eat the cost of a wideband.
Thread Information
Users Browsing this Thread
There are currently 1 users browsing this thread. (0 members and 1 guests)
Similar Threads
-
P0740 (no symptoms help)
By Letzride in forum Automatic TransmissionReplies: 5Last Post: 05-22-2014, 05:26 PM -
symptoms of a problem
By ncschall in forum General HelpReplies: 7Last Post: 02-07-2011, 07:09 PM -
Help: Cam symptoms
By Lunatikgixxer in forum Internal EngineReplies: 17Last Post: 10-27-2010, 07:10 PM -
Help: Symptoms of bad maf sensor?
By LS1junkie18 in forum General HelpReplies: 14Last Post: 02-22-2010, 04:10 PM -
What are the Symptoms of a bad cam lobe
By Justin93 in forum Internal EngineReplies: 6Last Post: 04-16-2009, 12:08 AM
Bookmarks