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Wierd idle, no low end power, and acts wierd at high speeds

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Old Jul 7, 2002 | 04:35 PM
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RallySport92RS's Avatar
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Wierd idle, no low end power, and acts wierd at high speeds

When I start my car up cold, the idle is at 1500rpm, when I start it warm, it goes to 1500 and slowly falls to about 300, then varies from 300-700 rpm.
When I hit the gas from a stop, there is absolutely no low end power anymore, it picks up after 40km/h, but until then it's very slow.
And when Im going about 100km/h and i floor it, it bogs down and doesnt move for about 3 seconds, then takes off quickly.
Anyone have any suggestions to help me out? i just had the LT1 cam installed and I did the AFPR mod and turned the screw 2 full turns from the bottom. Also, while doing the AFPR my friend slipped and hit my distributor and Im not sure where it should be so could this have messed it all up?
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Old Jul 7, 2002 | 09:03 PM
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From: Richmond, Virginia
Get a timing light and readjust your ignition timing. After fixing your timing, you may want to play with your fuel pressure, to see what works best for you. and as always, start looking into a custom chip.
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Old Jul 8, 2002 | 02:33 AM
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Motopsyco's Avatar
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From: Plainwell, Mi U.S.A.
Car: 89 firebird, 03 Avalanche z71
Engine: 5.0 stock (for now)
Transmission: 700R4 auto
Axle/Gears: stock 2.73 for now
what is the afpr mod and turning what screws, im always interested in bi engine mods, so what is it, and whats it do?, thanx
--Stormr
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Old Jul 8, 2002 | 08:43 AM
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https://www.thirdgen.org/newdesign/tech/tbi-afpr.shtml

That is the location of a how to, to convert your existing regulator to an adjustable one. Or you can buy a new one from a number of aftermarket companies. When you turn the screw one way the pressure is increased, and the other way it is decrease. This can be used for mild adjustments of fuel pressure. Personally I bought an aftermarket one, but many on these boards have done the conversion.
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Old Jul 8, 2002 | 08:56 AM
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RallySport92RS's Avatar
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The tab that sticks out of the fuel pressure regulator came out when I adjusted mine, was it supposed to??
the screw and the tab are all together and they're possible to turn, but when I drilled out the whole pressed in cap the entire thing popped out.
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Old Jul 8, 2002 | 09:16 AM
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I thought that the only thing that was suppose to come off of the original regulator was the cap over the screw.

"Step nine: Now to make that threaded shaft movable and furthermore, adjustable easily. You will have noticed the shaft does not move. Flip the cup over and take note of the pressed in cap in the hole on the bottom of the cup. This must be drilled out. Its pressed in there quite well, and is not easy just to pull out. I and others have had to completely drill out the cap.
Be carefull so as to not exert too much pressure as it is possible to knock out the metal peice that is pressed into the cup on the bottom in which the cap sits "

This is step 9. read the bottom part, is this what happened?
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Old Jul 8, 2002 | 10:15 AM
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Yeah I think thats what happened because I was left with 2 parts, the cup (with nothing in it) and then the metal piece with the screw attatched, which wasnt in it the cup
Would this do all those problems I was asking about before?
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Old Jul 8, 2002 | 11:40 AM
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im not sure if that is what caused the problem, but you probably arent able to adjust your fuel pressure appropriately. So i would advise getting another regulator from a junkyard and trying again, or just get any aftermarket one that is already adjustable. Good luck.
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Old Jul 8, 2002 | 12:28 PM
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RallySport92RS's Avatar
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Thanks for the luck! I already ordered a new one and Im having my mechanic install it and adjust my timing tomorrow.
I hope it all works out or I'll be back with more questions lol
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