350HO Tuning
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Joined: May 2003
Posts: 10
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From: KS
Car: 1500 Chyeene W/T
Engine: GMPP350/330
Transmission: Probuilt 4l60e 'Road Race'
350HO Tuning
All started when I dropped a GMPP 350/330 into a 1500 chevy...
Started with a custom chip which was basically blindly programmed... used 55lb inj @ 14psi (i know, not enough fuel) and 350TB on the GMPP TBI intake.
From there I bored the intake to 2" and installed a 454 with 68lb and a new chip from CFM-Tech supposedly made and pretuned specifically for this motor.
Took it into a mechanic to fix my high fuel pressure (due to a walbro pump install) and he ended up tearing off my 454 and reverting back to a stock 350, old chip, and 55lb. Oh, and he also told me not to touch it ever again. Of course, the fuel pressure was still set at 17psi when I got it back.
Sense then I stupidly misplaced my CFM-tech chip and so I'm stuck with the original. As of now i'm running a 454TB with 55lb injectors at 15psi.... needless to say it'll surge at idle and has some horrible dead spots that'll cause a backfire/ping if you give too much gas.
This come after replacing spark plugs, installing nology hotwires, 02, coolent sensor, and a brand new Probuilt 4l60E Road Race transmission - vacuum modulated. Also fixed the fuel pressure by installing an AFPR (not hooked to vac) on my frame rail and "Ting" into my return line to bleed off that extra few PSI before reaching the TBI FPR.
I know enough that no amount of timing advancement or fuel pressure adjustment will let the computer compensate... or am i wrong? Can I half *** get this thing close through PSI, timing, and reverting to the 350TB it was programmed for? If its possible I'd love to try before jumping into programming my own chips...
I really don't have the cash to start investing in a new hobby at the moment... If I find somebody with the same setup as me, can I use their bin and have somebody burn it for me?
Hopefully I can get by with FP and timing tweaks.. >_< but I KNOW that 55lb injectors just aren't going to cut it unless i crank up the pressure.... which I'm assuming he programmed the chip to use stock PSI...? Or does the computer not care?
Thank you!
Started with a custom chip which was basically blindly programmed... used 55lb inj @ 14psi (i know, not enough fuel) and 350TB on the GMPP TBI intake.
From there I bored the intake to 2" and installed a 454 with 68lb and a new chip from CFM-Tech supposedly made and pretuned specifically for this motor.
Took it into a mechanic to fix my high fuel pressure (due to a walbro pump install) and he ended up tearing off my 454 and reverting back to a stock 350, old chip, and 55lb. Oh, and he also told me not to touch it ever again. Of course, the fuel pressure was still set at 17psi when I got it back.
Sense then I stupidly misplaced my CFM-tech chip and so I'm stuck with the original. As of now i'm running a 454TB with 55lb injectors at 15psi.... needless to say it'll surge at idle and has some horrible dead spots that'll cause a backfire/ping if you give too much gas.
This come after replacing spark plugs, installing nology hotwires, 02, coolent sensor, and a brand new Probuilt 4l60E Road Race transmission - vacuum modulated. Also fixed the fuel pressure by installing an AFPR (not hooked to vac) on my frame rail and "Ting" into my return line to bleed off that extra few PSI before reaching the TBI FPR.
I know enough that no amount of timing advancement or fuel pressure adjustment will let the computer compensate... or am i wrong? Can I half *** get this thing close through PSI, timing, and reverting to the 350TB it was programmed for? If its possible I'd love to try before jumping into programming my own chips...
I really don't have the cash to start investing in a new hobby at the moment... If I find somebody with the same setup as me, can I use their bin and have somebody burn it for me?
Hopefully I can get by with FP and timing tweaks.. >_< but I KNOW that 55lb injectors just aren't going to cut it unless i crank up the pressure.... which I'm assuming he programmed the chip to use stock PSI...? Or does the computer not care?
Thank you!
