Results 1 to 20 of 21
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06-20-2011, 06:42 PM #1
- Join Date
- Jun 2011
- Location
- tasmania
- Posts
- 6
alantic silver- 99 vt calais ls1
Strange flat spot or surge at 1800 to 2/2500 rpm
Hi there got a Vt Calais 99 mod Ls1 auto
Anyway notice this bloody flat spot replaced
O2 sensors
Tps
Fuel filter
Cleaned maf
And cleaned all the earth cables to the body
Still have plugs and leads to do which will be this wk but it will rev and idle so maybe not that!
I have noticed if u use auto lik a manual and go through the gears problem gone or if it's cold in the morning it's gone this is really getting to me now as it isn't giving me any codes . it will rev out all the way and idle lik a gem but what is this 200 to 500 rpm I'm losing its lik a choke then comes bak I've notice if I keep acc throught it it seem to get worst or go past it but I think it causes pinging aswell any help would be goodLast edited by muzza304; 06-20-2011 at 06:58 PM.
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06-20-2011, 07:40 PM #2
- Join Date
- Jan 2009
- Location
- North Jersey
- Posts
- 11,496
Phantom Black Metallic- 2004 GTO M6
How is your fuel pump? Have you checked your fuel pressure?
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06-20-2011, 07:50 PM #3
- Join Date
- Jun 2011
- Location
- tasmania
- Posts
- 6
alantic silver- 99 vt calais ls1
Seems ok revving all the way out but worth a look it feels electrical to me as soon as it hot it's happens maybe coolet sensor I dunno all guess,s now
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06-20-2011, 08:20 PM #4
- Join Date
- Jan 2009
- Location
- North Jersey
- Posts
- 11,496
Phantom Black Metallic- 2004 GTO M6
Check your coolant sensor then. Check the harness going to your coolant sensor as well.
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06-22-2011, 07:47 PM #5
- Join Date
- Feb 2010
- Location
- Springfield, Missouri, United
- Posts
- 221
Maroon- 2000 z28 6 speed
Check your coils!! they can cut out at certain RPM.
2001 B4C Totaled 4/25/11
2000 Z28 M6 Cammed N' Slammed (SVT KLR)
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06-23-2011, 01:11 AM #6
- Join Date
- Jun 2011
- Location
- tasmania
- Posts
- 6
alantic silver- 99 vt calais ls1
Ok well spk plugs and leads replaced but still has hesitation but it's moved up revs around 2000 to 2300 but only now and then so I stopped car after hot and checked coil and found 8 and 6 are sparking on the coil bolts which make me think that's the problem as it revs fine after the cough moment so stay tuned as saving for coil at moment
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06-23-2011, 06:41 AM #7
- Join Date
- Mar 2007
- Location
- NC
- Posts
- 421
NBM- 1998Z28
Your probally running 2.73 rear gears. I always noticed a flat spot when I ran that gear ratio back when the car was stock. If thats the case a set of 3.73s will take care of it. If you really want to get going get you a 3200 Vigalante convertor.
TSP 347 SB, TSP Stage 2.5 PRC LS6, TSP MS4, Performabuilt Stage 2 4L60E, Yank PT4000, 4.11s, Fast 90/90, FTRA Cold air intake+all the free mods, Dynatech Supermaxx Exaust System, DMH Cutouts, Hooker Catback/FTRA Tips. Tuned by RPM/Garner NC. 11.28@119
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06-23-2011, 07:57 AM #8
- Join Date
- Feb 2010
- Location
- Springfield, Missouri, United
- Posts
- 221
Maroon- 2000 z28 6 speed
coils can act different at idle to RPM range. they can become weak enough to almost clip out when the sparking is required faster. plus you only checked 2
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06-23-2011, 07:06 PM #9
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06-24-2011, 04:41 AM #10
- Join Date
- Feb 2010
- Location
- Springfield, Missouri, United
- Posts
- 221
Maroon- 2000 z28 6 speed
I'm thinking coils too
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06-26-2011, 07:13 AM #11
- Join Date
- Jun 2011
- Location
- tasmania
- Posts
- 6
alantic silver- 99 vt calais ls1
well took coils off and checked for any signs of hot spots but relised ths problem is when hot or cold im lost now im thnking still should replace coils just costing a heap now anyone else with ideas
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06-26-2011, 04:23 PM #12
- Join Date
- Jan 2009
- Location
- North Jersey
- Posts
- 11,496
Phantom Black Metallic- 2004 GTO M6
Replace coils 6 and 8 and keep us posted.
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09-09-2011, 08:13 AM #13
- Join Date
- Jun 2011
- Location
- tasmania
- Posts
- 6
alantic silver- 99 vt calais ls1
ok ended up getting a tuner to look at ls1 and found 2 injectors blocked up and seals cracking ended up being an easily fix hope this helps
and coils are fine cheers for the help anyway
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09-09-2011, 11:16 AM #14
- Join Date
- Jan 2009
- Location
- North Jersey
- Posts
- 11,496
Phantom Black Metallic- 2004 GTO M6
Good to hear. Enjoy that Holden!!!
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09-09-2011, 01:07 PM #15
- Join Date
- Aug 2010
- Location
- Oklahoma City, Oklahoma
- Posts
- 1,807
sebring silver- Y2K SS CAMARO
damn and i was just about to say take it to a tuner
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09-13-2011, 12:05 PM #16
Trying to learn, Isn't a tuner basically a mechanic who specializes in troubleshooting complex fuel injection? cars not just LS-1's but all fuel injection cars can prove hard to find where faults are without tons of experience with certain cars ect?
Now basically they charge what mechanics charge ?
Cracking seals indicates heat and age deteriation so with these complex systems now 13 years and older other injected cars older troubleshooting can be the main issues?
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09-14-2011, 03:20 AM #17
- Join Date
- Nov 2010
- Location
- Upstate Ny
- Posts
- 88
- 99 Formula
disconnect your maf and drive around and wait till it get up to operating temp to make your decision , i have to replace my maf , only hiccups at 1500-2000 when up shifting and driving easy but its so annoying and noticeable . I disconnected the maf and drove it , perfectly fine and no misfires and runs great .
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09-14-2011, 08:45 AM #18
Now that makes no sense to me at all i figure that the maf is looking for a density quanity quality of air ?
To me it would say that ecm senses no air as its unplugged it would just idle maybe or shutdown maybe, thats the difficulty of computer controlled fuel injected cars from just my 2 cents worth?
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09-14-2011, 10:48 AM #19
- Join Date
- Jan 2009
- Location
- North Jersey
- Posts
- 11,496
Phantom Black Metallic- 2004 GTO M6
These cars can run with a disabled MAF on their "Speed Density" programming from the factory. If I recall, though, the car cannot run past a certain RPM. Someone will give better info soon.
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09-14-2011, 12:31 PM #20
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