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HybridZ

Major Flat Spot Question!!!!


alsil

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OK, I took the Z out to Sears Point last Wednesday, and I wound up finding a HUGE flat spot I didn't have before, just after 1/3 throttle. Now here's a bit of detail that's important:

 

1995 Ford 5.0 motor

Edelbrock Performer Intake

Edelbrock Performer Carb, 600CFM

Adjustable fuel pressure regulator

Carter Electric Fuel pump

 

Here's what I'm thinking. The Fuel pump was putting out 13psi without the regulator. The regulator is set at 3.5 psi I think. Now to me, that seems really low. Should be like 5psi to keep up with the engine, right?

So what I'm thinking is I'm going to start the pump (key on) and let it fill the filter and the fuel bowl. Then I'm going to turn it off and pop the top of the carb and check the level. If it's low, then I know the pressure is too low.

Now my real question, is that if the fuel bowl runs low, wouldn't the car pop? Wouldn't I get a lean pop through the carb if the secondaries open and no fuel mixes with it? I checked my air valve (a weighted throttle blade above the actual secondaries to regulate how much air goes through, supposed to only let as much air as the engine needs through) and it seems to work fine (it's not stuck at least).

The only other thing I can think of is that there's something stuck in my jets and I need to rebuild the carb.

As far as NON carb issues that might give me a flat spot, I'm going to check my timing (although it's an MSD Billet setup, shouldn't EVER need to mess with it), and check my plugs.

Anyone have any ideas? I want to bring my Z out to Sears Point November 13th to run it again if I can get it going.

And yes, I know I should be running a Holley if I want to race!!!!! Just don't want to be messing with it every time I drive it!

Thanks

Al

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Well I found the problem with the bogging. took a bit of screwing around, first I didn't see any problem with the carb....

 

1. Took out the Air Valve

2. Turned fuel regulator to 4.5 psi (the float boals were a bit shallow)

3. Fixed the timing (not advanced enough)

 

Guess that all the driving the day of Sears it had been backing off all day. I should have brought my timing light like the old days, I would have figured it out. the dist bolt was a little tiny bit loose, so it was slowly losing timing (DOH! frown.gif )

Oh well........next time.

Going out November 13th.....anyone wanna come? :D

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