running out of power up high
Thread Starter
Member
Joined: Feb 2001
Posts: 138
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From: windsor Ont. Canada
running out of power up high
I race my friend in his 4.7L dodge dakota, and sadly it was a close race. Off the line I took him easily but when i hit about 4000 the power just started to die off and he caught back up. But when my car shifted into second at 5500(and dropped to 3000) it practally jumped ahead 10ft instantly, and then i took him. Does this mean that the fuel pump is bad, or going. Or mabye a lean out up high. But it never did it before. Please help, I should be able to walk away from one of those.
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82 Z28 have LG4-305"
Rebuilt heads-3 angle valve job,ported and gasket matched. comp cam xtreme energy 262 edelbrock performer, chevy 1.6:1 roller rockers,MSD6AL, rebuilt carb,15x4" K&N
3"flowmaster american thunder, Mac high flow cat,headman headers,
700-R4--B&M shift kit, B&M tranny cooler.
Sub-frame connectors, boxed lower control arms and torque arm. 1.5" front sway bar, new BFgoodrich radial T/A's--215/65 front 255/60 rear
RADIO-- premier Deh-p300
2-10"kicker SPLs,ZR240,premier 434x(4 way), custom built fiberglass box for subs. pioneer 6X9 & 4X6, grant GT steering wheel
------------------
82 Z28 have LG4-305"
Rebuilt heads-3 angle valve job,ported and gasket matched. comp cam xtreme energy 262 edelbrock performer, chevy 1.6:1 roller rockers,MSD6AL, rebuilt carb,15x4" K&N
3"flowmaster american thunder, Mac high flow cat,headman headers,
700-R4--B&M shift kit, B&M tranny cooler.
Sub-frame connectors, boxed lower control arms and torque arm. 1.5" front sway bar, new BFgoodrich radial T/A's--215/65 front 255/60 rear
RADIO-- premier Deh-p300
2-10"kicker SPLs,ZR240,premier 434x(4 way), custom built fiberglass box for subs. pioneer 6X9 & 4X6, grant GT steering wheel
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Joined: Jan 2000
Posts: 19,660
Likes: 311
Black,
It's possible that the fuel pump is failing. A fuel delivery problem can also be caused by a clogging fuel filter, restricted fuel line from crimped steel lines or hoses, a sharply bent hose, or a clogged pickup screen in the fuel tank. With a mechanical pump, you can usually blow the lines backward with compressed air to help clear the pickup screen. Inspect the lines for damage and kinks. Change the fuel filter, fill the carburetor and start the engine with the fuel line removed and placed in a container. The pump should deliver a quart of fuel per minute.
It's also possible you have weak spark energy that won't ignite the mixture reliably at those speeds. This could be from a weak coil, failing wires, excessive plug gaps, worn rotor or distributor cap, heavily rusted reluctor and/or pickup coil, or a failing HEI module.
It's also possible that the valve springs are weak, and cannot prevent the valves from floating at higher engine RPMs. Factory valve springs are really bad about this. They are soft enough that they won't wear out a cam lobe, but also don't control the valves very effectively. 4,000-4,500 RPM is a very common point of failure with this phenomenon. It jsut gets worse as the engine speed increases.
It would suck to lose to a "Nopar". I hope I never find out what that's like.
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Later,
Vader
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If you want to beat the World, it might reach up and pull you down...
Adobe Acrobat Reader
It's possible that the fuel pump is failing. A fuel delivery problem can also be caused by a clogging fuel filter, restricted fuel line from crimped steel lines or hoses, a sharply bent hose, or a clogged pickup screen in the fuel tank. With a mechanical pump, you can usually blow the lines backward with compressed air to help clear the pickup screen. Inspect the lines for damage and kinks. Change the fuel filter, fill the carburetor and start the engine with the fuel line removed and placed in a container. The pump should deliver a quart of fuel per minute.
It's also possible you have weak spark energy that won't ignite the mixture reliably at those speeds. This could be from a weak coil, failing wires, excessive plug gaps, worn rotor or distributor cap, heavily rusted reluctor and/or pickup coil, or a failing HEI module.
It's also possible that the valve springs are weak, and cannot prevent the valves from floating at higher engine RPMs. Factory valve springs are really bad about this. They are soft enough that they won't wear out a cam lobe, but also don't control the valves very effectively. 4,000-4,500 RPM is a very common point of failure with this phenomenon. It jsut gets worse as the engine speed increases.
It would suck to lose to a "Nopar". I hope I never find out what that's like.
------------------
Later,
Vader
------------------
If you want to beat the World, it might reach up and pull you down...
Adobe Acrobat Reader
Thread Starter
Member
Joined: Feb 2001
Posts: 138
Likes: 0
From: windsor Ont. Canada
I dont think it is the valve springs because they are the ones reccommended by comp for that cam shaft. I hope it is not the spark because I have new wires, a MSD 6al, accel high power coil, cap and rotor. But it might be the cap and rotor because they are starting to melt from the power made by the ignition. I hope it is just the fuel pump. thanks for the help, does anyone else have an idea?????
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