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Discussion Starter · #1 ·
I have decided my problem is a lack of volume. My Carter strip pump has a problem that I can't see when I open it up but it is not supplying what it did a few races ago. What pumps have you tried and what do you think about them? I am trying to decide if I should get another Carter or try something else.
 

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Discussion Starter · #3 ·
Its my dads car and he is running a 327 with a 284 .458 lift lunati cam, RPM intake and 650 DP. The car ran 13.80's at 98 mph the first time we ran it. The next week it would only run 14.40's with a lean pop at 5000 rpm. We have checked every thing from the tank to the carb and found nothing. Last week we bypassed the filter and reg. with no change. I have over jetted trying to get it to run rich but the plugs are white and I still get a lean pop. The pump makes 8 psi at idle but drops to about 4 when I gas it. It does seem to be getting worse with each pass.
 

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4 psi @ w.o.t doesn't seem too bad. Kinda wierd that it's getting worse. I was running a Holley mechanical pump. Had a problem with fuel starvation, but it was the carb, not the pump. Is it possible maybe the filter is clogged? I wouldn't run the car too much in that condition, it could burn a valve. I'm going to think on this a bit and I'll post if I think of something else.
 

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Discussion Starter · #6 ·
We put my gauge on after the car slowed down. When the rpm would get to 4000 the psi would drop to 3. We checked the filter first and it was fine. We dropped the tank and found the sock had pulled together and we took it off. This helped the pressure drop but E T was still off. Vent line is clear and no bad bends in the fuel line. There is no blockage in any off the line and at this point I have no regulator or filter and the floats are high. The ET is off 1/2 second and the 60' is off a tenth. The 60' is what puzzles me the most and is why I am thinking fuel pump.
 

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Discussion Starter · #7 ·
I know more than one person has an idea about mech. fuel pumps. I am at a wall here. Any body out there.
 

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In my 70 chevelle with a 383 I was hitting 13.3's with a stock pump and 5/16 fuel line with no problems. I tried a holley street pump with same results. The 383 is now in my 67 Camaro hitting low 12's at 110 still with the holley street pump and 5/16 line with no problems.

In my other Camaro I have an Edelbrock race mechanical pump, 6 valve design, 1/2" fuel line to pump 3/8 to carb. Hits 11.6's at 117 with no problems.

Since your times are down across the board, you engine is down on power for another reason.

Lonnie

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70 Chevelle 15.01 @96
67 Camaro street strip 11.63 @117.6
67 Camaro daily driver 12.10 @110.6
www.geocities.com/lonnie67_1966

[This message has been edited by Lonnie67 (edited 07-15-2001).]
 

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Discussion Starter · #9 ·
Thanks for the examples. I have a bad lean problem that came out of nowhere. I went back into the pump today and found that one of the inlet valves may be letting fuel push back to the tank. I was able to suck air back through the inlet but I could not blow air back through the outlet.
 

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I run the Edelbrock 6 valve mechanical pump on a big block with nitrous and it feeds it all fine.
The spring in your fuel pump could be weak causing the pump pushrod to float at higher RPM.
Get a new fuel pump and a Moroso Hollow fuel pump pushrod.

[This message has been edited by Bob Tiley (edited 07-16-2001).]
 

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Check your float levels, primary and secondary.
I think 3 lbs of pressure is too low.
I am running a high volume pump from Summit
454 5/16 line, Holley 750, no problems.
 

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Discussion Starter · #13 ·
Thanks for the input. We went with the Carter pump in order to have more fuel than we needed and regulate it. From the times listed here we are going to try a stock pump, its alot cheaper.
 

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Haven't drag raced since the mid 70's, but then I had a 69 Camaro with an LT1 350, M22, off-road Z28 cam, Edelbrock Tarantula intake (I know, I know, I'm dating myself here....) a 750 DP Holley, 4.88 gear, and whatever size fuel line came stock on a 69 Z28 Camaro. Ran 11.90's. Used only an AC mechanical pump that was OEM on the L79 327. Never had any fuel starvation problems.

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Bill Pritchard
69 SS396 Convertible
"Life is short; eat dessert first." - Ogden Nash
My low tech web page
 
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