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Cutting out at 4200 rpm
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Author:  Dave95693 [ Sat Sep 10, 2011 9:35 pm ]
Post subject:  Cutting out at 4200 rpm

High performance 225 cutting out at 4200 rpm under load. Running a 750 holley with 67 jets in the front and 68 jets in the back. Changed to these from 65 jets in both sides. No change. Running a stock electronic ignition with orange box and an Accel coil. Runs the same with or without ballast resistor.
Runs the same with or without the voltage regulator. (dont ask) Runs the same off the battery at 12.6 volts or at 14 volts.

All grounds have been checked and paint stipped where attached.

Alternator is new and working correctly.

Problem seems to get worse the more I run the car although temp gauge never exceeds 180 degrees.

Any ideas?

Author:  raPoM [ Sat Sep 10, 2011 9:40 pm ]
Post subject: 

I wonder how the diaphram in your fuel pump is doing? I have also heard of similar problems with the newer orange boxes....

Author:  Dave95693 [ Sat Sep 10, 2011 9:43 pm ]
Post subject: 

I'm getting 5 psi at the fuel regulator which should be plenty. I too suspect the orange box as it is one of the pieces to the new ignition system I put in.

Thanks for the reply by the way.

Author:  Fopar [ Sat Sep 10, 2011 9:49 pm ]
Post subject: 

Do the HEI conversion and you will probably never look back.

Richard

Author:  Dave95693 [ Sat Sep 10, 2011 9:58 pm ]
Post subject: 

Howdy Richard. Yes that is a possibility. Since I have a Petronix II new in the box I want to try that first to see if it indeed changes. Mark Guzzi has me doing retorque and valve adjust to eliminate to close of valve clearances. So I have those to try in the morning. Too tired tonight. I've been working on this car for some time and am getting weary of turning wrenches on it.

Thanks for the response.

Dave

Author:  emsvitil [ Sat Sep 10, 2011 10:09 pm ]
Post subject: 

Does it maintain the 5psi at WOT?

I'm thinking you're draining the fuel bowl (pump can't keep up)

Let up (hold rpm, wait a bit for pump to fill bowl) and then refloor it.

Author:  Fopar [ Sat Sep 10, 2011 10:28 pm ]
Post subject: 

If the Petronix doesn't have a control module all you will change is the points and if you are using an electronic distributor only rule out pickup coil.

Richard

Author:  olafla [ Sun Sep 11, 2011 6:15 pm ]
Post subject: 

Double check all your ground connections, and you should also test with another coil. I had similar problems once, when a coil refused to perform when it got hot.

Olaf.

Author:  Dave95693 [ Tue Sep 13, 2011 11:33 am ]
Post subject: 

Thanks for all your thoughts.
As it turns out it was the orange ignitor box that was the problem. I pulled that on the distributor it came with, installed a Petronix II and all my problems vanished.


Thanks again fellas. You were all a great help.

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