upper end dead spot
TECH Senior Member
Joined: Nov 2001
Posts: 9,246
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From: Troy, AL
Re: upper end dead spot Need more details. What RPMs are we talking about (you didn't state your transmission, tire size, or gearing.) Any Autotap data? Can you describe in more detail about the dead spot? Do it all the time? Any changes made recently?
Adkoonerstrator
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From: Deep in the seedy underworld of Koonerville
Re: upper end dead spot This is just a guess since you didn't give us much info. <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />
Do you have an automatic with 3.23 gears? If so a nice 3500+ stall will get rid of that dead spot. <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />
John
Do you have an automatic with 3.23 gears? If so a nice 3500+ stall will get rid of that dead spot. <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />
John
Thread Starter
On The Tree
Joined: Apr 2002
Posts: 127
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From: tampa florida
Re: upper end dead spot sorry, about the lack of info.it's a 98z ls1,six speed,factory 3.42.current mods are whisper lid,holly air filter,hpp3,flowmaster cat back,spec-stag 2 clutch assy,msd wires,hurst comp+ shifter,egr mod,ram air mod,maf housing mod/porting.during the porting process,the power grinder came apart and cut a noticaeable area in the housing.the final result i was not happy with.could this be causing my dead spot.as far as my rpm range at that time,i'm just starting 4th gear.i know it's not high,it's right befor the traps. thanks for any help you can give me. ed f
TECH Senior Member
Joined: Nov 2001
Posts: 9,246
Likes: 3
From: Troy, AL
Re: upper end dead spot Ok, assuming you're not talking about the normal loss of acceleration from shifting into 4th...
Could be that you damaged your MAF sensor. Did it seem to have this dead spot before the port job? Do you have any Autotap data? That would really help. We could see if you're leaning out for any reason or if you're getting some knock retard.
Could be that you damaged your MAF sensor. Did it seem to have this dead spot before the port job? Do you have any Autotap data? That would really help. We could see if you're leaning out for any reason or if you're getting some knock retard.
"All Motor 9 Second club member"
iTrader: (60)
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From: On the Bumper!
Re: upper end dead spot It sounds like the cat over temp feature causing the flat/dead spot. Several others were having something similar happen. It's almost like a plugged fuel filter. It was eliminated by using LS1 edit and choosing False under cats catagory. Apparently the PCM goes pig rich under WOT to help cool the cats down. Here is the link and I hope it helps out. Good luck.
https://ls1tech.com/ubb/cgi-bin/ulti...&f=24&t=002933
https://ls1tech.com/ubb/cgi-bin/ulti...&f=24&t=002933
Thread Starter
On The Tree
Joined: Apr 2002
Posts: 127
Likes: 0
From: tampa florida
Re: upper end dead spot thanks for all the help.i did find the problem,a bad hhp3 programer!with stock performance tuning the problem was resolved.check out my post,shifting point/dead spot problem solved.i also give a 1-800 number to call hypertech,no more long distance calls.
