My 300 hits a wall when accelerating.

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SinCityLocal
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My 300 hits a wall when accelerating.

Post #1 by SinCityLocal » Sun Jul 22, 2018 1:56 pm

I don't have a tachometer yet, so I don't know exactly where it happens. I have a 95 F-150 EFI 300 5 speed. It pulls strong until it flattens out. My guess is 3800-4000 rpm range. More accelerator seems to do nothing. I bought this truck cheap because it had a cracked head. Replaced it and the radiator, and have been driving it for about 6 months. Is this a typical characteristic of the EFI 300, or is there something wrong that I need to look for?

pmuller9
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Re: My 300 hits a wall when accelerating.

Post #2 by pmuller9 » Sun Jul 22, 2018 2:34 pm

Peak horsepower is around 3400 rpm

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THE FRENCHTOWN FLYER
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Re: My 300 hits a wall when accelerating.

Post #3 by THE FRENCHTOWN FLYER » Sun Jul 22, 2018 3:57 pm

All 300s, carbed or EFI start to "nose over" at 4000RPM. The best improvement to start out with is a freer flowing exhaust system / muffler.
FORD 300 INLINE SIX - THE BEST KEPT SECRET IN DRAG RACING

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MechRick
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Re: My 300 hits a wall when accelerating.

Post #4 by MechRick » Mon Jul 23, 2018 12:15 am

Mine's all done at 4400, and that's a ported head with stock valves. Nature of the (stock) beast...
1994 F150, 4.9L/ZF 5 speed, C-Vic police driveshaft
EFI head w/mild port work, 3 angle valve job
1996 long block, stock pistons, ARP rod bolts
Stock cam, aluminum cam gear
Hedman header, full mandrel bent duals, crossover, super turbos
http://fordsix.com/forum/viewtopic.php?f=2&t=73244
Bronco II with a 2.3L swap http://fordsix.com/forum/viewtopic.php?f=13&t=72863
1988 F250 2x4, 460 ZF 5 speed.

1986F150six
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Re: My 300 hits a wall when accelerating.

Post #5 by 1986F150six » Thu Jul 26, 2018 11:31 am

Mine [stock] makes nothing but additional noise after ~3000 rpms. :lol:

Harte3
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Re: My 300 hits a wall when accelerating.

Post #6 by Harte3 » Thu Jul 26, 2018 1:56 pm

Mine jumps to 4000 rpm as easily as 3000 rpm but the rate starts to slow down at about 4500 rpm and hits the wall at 5000 rpm. That is on a mild/moderate build.
'83 F150 300, 0.030 over, Offy DP, Holley 4160/1848-1 465 cfm, Comp Cam 260H. P/P head, EFI exhaust manifolds, Walker Y Pipe, Super Cat, Turbo muffler, Recurved DSII, Mallory HyFire 6a, ACCEL Super Stock Coil, Taylor 8mm Wires, EFI plugs.

SinCityLocal
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Re: My 300 hits a wall when accelerating.

Post #7 by SinCityLocal » Thu Aug 16, 2018 11:27 pm

I recently got and installed a tach cluster. Boy was I way off with my rpm estimate. Tonight, I went for a drive and found that my issue starts at 2500 rpm like clockwork. Pushing past 3000 is nerve racking because it takes so long to get just to that point. It's hard for me to believe this is a fuel issue, but I'm open to any suggestions for where to start my search. The plugs are new and gapped at .044 with new wires, cap and rotor.

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THE FRENCHTOWN FLYER
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Re: My 300 hits a wall when accelerating.

Post #8 by THE FRENCHTOWN FLYER » Fri Aug 17, 2018 9:12 am

Melted / plugged catalytic converter?
FORD 300 INLINE SIX - THE BEST KEPT SECRET IN DRAG RACING

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B RON CO
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Re: My 300 hits a wall when accelerating.

Post #9 by B RON CO » Sat Aug 18, 2018 9:00 pm

Hi, I like the clogged exhaust idea. I would also make sure the distributor timing is set properly and is advancing as it should. Good luck
B RON CO. Still workin' on it!

1933 Ford Pickup - 59A Flathead V8
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