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Power valve problems.? or #363851 07/01/09 08:06 PM 07/01/09 08:06 PM
Joined: Feb 2006 Posts: 188 Murrayville, Illinois, usa S scotts66charger OP member
scotts66charger OP member S Joined: Feb 2006 Posts: 188 Murrayville, Illinois, usa	We have a 440 with lots of tweeks done to it (aprox 425 HP). Have a 750HolleyDP on it. we moved from an elevation of 4000 feet to 300 foot. I've had problems ever since. Changed the front jets to bigger, and got rid of most of the hesitation in the launch, but now have a bad Bad miss fire (maybe backfire) after I hammer it in 1st gear (well in all gears (auto trans). Do you think the power valve might be bad?

Re: Power valve problems.? or [Re: scotts66charger] #363852 07/01/09 08:25 PM 07/01/09 08:25 PM
Joined: Nov 2003 Posts: 36,040 Lincoln Nebraska R RapidRobert Circle Track
RapidRobert Circle Track R Joined: Nov 2003 Posts: 36,040 Lincoln Nebraska	Quote: Do you think the power valve might be bad? I would check your plugs/wires live every 24 hour block of time like it's your last day on earth

Re: Power valve problems.? or [Re: scotts66charger] #363853 07/01/09 09:14 PM 07/01/09 09:14 PM
Joined: Apr 2007 Posts: 1,261 ILL mark7171 pro stock
mark7171 pro stock Joined: Apr 2007 Posts: 1,261 ILL	If nothings leaking in the carb , backfires are usually timming. are you driving a race car with no vacuum advance ?

Re: Power valve problems.? or [Re: mark7171] #363854 07/02/09 12:50 AM 07/02/09 12:50 AM
Joined: Jan 2003 Posts: 9,826 las vegas 70AARcuda master
70AARcuda master Joined: Jan 2003 Posts: 9,826 las vegas	try a larger squirter... Tony 70 AARCuda Vitamin C 71 Dart Swinger 360 10.318 @ 128.22(10-04-14 Bakersfield) 71 Demon 360 10.666 @122.41 (01-29-17 @ Las Vegas) 71 Duster 408 (10.29 @ 127.86 3/16/19 Las Vegas)

Re: Power valve problems.? or [Re: 70AARcuda] #363855 07/03/09 12:18 PM 07/03/09 12:18 PM
Joined: Feb 2006 Posts: 188 Murrayville, Illinois, usa S scotts66charger OP member
scotts66charger OP member S Joined: Feb 2006 Posts: 188 Murrayville, Illinois, usa	The carb is not leaking. The engine runs very well when Im just cruzing around, so I dont know about the plug wires. If it runs good, (and if the plug wires were bad, wouldnt it run bad all the time?). This sounds dumb, what whats a squirter?

Re: Power valve problems.? or [Re: scotts66charger] #363856 07/03/09 12:46 PM 07/03/09 12:46 PM
Joined: Jan 2003 Posts: 32,935 Grand Prairie,Texas stumpy I Win
stumpy I Win Joined: Jan 2003 Posts: 32,935 Grand Prairie,Texas	Sqirter=Acclerator pump.

Re: Power valve problems.? or [Re: scotts66charger] #363857 07/03/09 03:33 PM 07/03/09 03:33 PM
Joined: Nov 2003 Posts: 36,040 Lincoln Nebraska R RapidRobert Circle Track
RapidRobert Circle Track R Joined: Nov 2003 Posts: 36,040 Lincoln Nebraska	Quote: If it runs good, (and if the plug wires were bad, wouldnt it run bad all the time?). This sounds dumb, what whats a squirter? There are no dumb questions only unasked ones. You didn't change anything after the move ex the jets? I think a plug/wire(s)were marginal & happened to cross the line just coincidentally after you moved unless you inadvertently jostled something during the jet change & yes a plug/wire(s) can seem OK but cannot handle the increased required voltage of full throttle. And you didn't change the timing at all? live every 24 hour block of time like it's your last day on earth

Re: Power valve problems.? or [Re: scotts66charger] #363858 07/03/09 03:45 PM 07/03/09 03:45 PM
Joined: Jul 2007 Posts: 531 Virginia J JimG mopar
JimG mopar J Joined: Jul 2007 Posts: 531 Virginia	Quote: This sounds dumb, what whats a squirter? To elaborate on Stumpy's reply: the accelerator pump circuit has two easily-changeable items available as a tuning aid - the pump cam and the "squirter", or the accelerator pump discharge nozzle. Various cams are available with different profiles that allow you to tailor the pump shot to throttle position. Bog when you nail it? You need a cam that will give the most volume of gasoline. Stumble when you slightly depress the throttle? You might need a cam that gives most of it's shot in the beginning of throttle movement, like a blue #427 cam. Change to a cam with more volume but don't change the nozzle and fuel will squirt at the same flow rate, but for a longer duration. Discharge nozzles come in various orfice diameters. You'll find that they're numbered. A #35 nozzle has an orfice diameter of .035". Increase the size of the discharge nozzle but don't change the cam, and fuel will squirt at an increased flow rate, but for a shorter duration (because the additional flow exhausts the pump sooner). Cams change the duration and profile of accelerator pump discharge. Discharge nozzles change the flow rate. There are also larger accelerator pumps available. Jim

Re: Power valve problems.? or [Re: JimG] #363859 07/06/09 01:12 AM 07/06/09 01:12 AM
Joined: Feb 2006 Posts: 188 Murrayville, Illinois, usa S scotts66charger OP member
scotts66charger OP member S Joined: Feb 2006 Posts: 188 Murrayville, Illinois, usa	Wow,lots of info. I will read through them all again, and try what you have posted. Thanxs again to you ALL for the help !! Rev. scott.

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