What should I look for?
Thread Starter
Melting Slicks
Joined: Jan 2003
Posts: 2,713
Likes: 31
From: Shreveport LA
LA Events Coordinator
UPDATE What should I look for? UPDATE!!
My engine seems to be "straining" whenever I go over 75mph (3,000 rpms). Everywhere else that I maintain under 75mph and normal interstate driving (70mph) and it runs smooth and doesn't strain. Even in city traffic, it runs smooth....600 rpms at red lights and in Drive....take offs are smooth....no missing or hesitations. Any suggestions?????
Last edited by vetteguy75; Feb 8, 2017 at 09:15 PM.
Instructor
Joined: Jul 2016
Posts: 195
Likes: 37
From: Poway CA
My engine seems to be "straining" whenever I go over 75mph (3,000 rpms).
I'm curious to know what you mean by "straining." Could you be a little more specific if possible. I think the members might need a little more to go on for more suggestions if the tune-up doesn't take care of the issue.
The car doesn't appear to be stock on the outside... is the engine mostly stock with q-jet?
I'm curious to know what you mean by "straining." Could you be a little more specific if possible. I think the members might need a little more to go on for more suggestions if the tune-up doesn't take care of the issue.
The car doesn't appear to be stock on the outside... is the engine mostly stock with q-jet?
Thread Starter
Melting Slicks
Joined: Jan 2003
Posts: 2,713
Likes: 31
From: Shreveport LA
LA Events Coordinator
My engine seems to be "straining" whenever I go over 75mph (3,000 rpms).
I'm curious to know what you mean by "straining." Could you be a little more specific if possible. I think the members might need a little more to go on for more suggestions if the tune-up doesn't take care of the issue.
The car doesn't appear to be stock on the outside... is the engine mostly stock with q-jet?
I'm curious to know what you mean by "straining." Could you be a little more specific if possible. I think the members might need a little more to go on for more suggestions if the tune-up doesn't take care of the issue.
The car doesn't appear to be stock on the outside... is the engine mostly stock with q-jet?
By "straining" I mean, when I hit 75mph/3,000 RPMs, the engine vibrates a lot and acts like it's not getting enough of either fuel, spark or air. AND when I continue pass that point, the engine vibrates more, and strains to accelerate.
Instructor
Joined: Jul 2016
Posts: 195
Likes: 37
From: Poway CA
I'm just throwing out ideas here, but I'm sure that's what you're looking for...
It helps a lot to know that it is vibrating only at higher rpm's and won't accelerate much past 3000. If all else seems normal, idle, cruise, light acceleration, water temp, etc, you may want to look at:
clogged fuel filter/or really clogged air filter
points need dwell adjusting or replacing if not electronic ignition
timing upset somehow, maybe too far advanced
float going bad, too low
fuel pump diaphragm tear/ check pressure
Bad spark wires, burned by headers? Sometimes, the extra torque and rpm can make a wire move and burn/arc only in that situation
lightly broken valve springs can act up at higher rpm. I've had broken springs behave entirely differently from each other
Let us know more as you troubleshoot and what you find.
It helps a lot to know that it is vibrating only at higher rpm's and won't accelerate much past 3000. If all else seems normal, idle, cruise, light acceleration, water temp, etc, you may want to look at:
clogged fuel filter/or really clogged air filter
points need dwell adjusting or replacing if not electronic ignition
timing upset somehow, maybe too far advanced
float going bad, too low
fuel pump diaphragm tear/ check pressure
Bad spark wires, burned by headers? Sometimes, the extra torque and rpm can make a wire move and burn/arc only in that situation
lightly broken valve springs can act up at higher rpm. I've had broken springs behave entirely differently from each other
Let us know more as you troubleshoot and what you find.
Thread Starter
Melting Slicks
Joined: Jan 2003
Posts: 2,713
Likes: 31
From: Shreveport LA
LA Events Coordinator
I'm just throwing out ideas here, but I'm sure that's what you're looking for...
It helps a lot to know that it is vibrating only at higher rpm's and won't accelerate much past 3000. If all else seems normal, idle, cruise, light acceleration, water temp, etc, you may want to look at:
clogged fuel filter/or really clogged air filter
points need dwell adjusting or replacing if not electronic ignition
timing upset somehow, maybe too far advanced
float going bad, too low
fuel pump diaphragm tear/ check pressure
Bad spark wires, burned by headers? Sometimes, the extra torque and rpm can make a wire move and burn/arc only in that situation
lightly broken valve springs can act up at higher rpm. I've had broken springs behave entirely differently from each other
Let us know more as you troubleshoot and what you find.
It helps a lot to know that it is vibrating only at higher rpm's and won't accelerate much past 3000. If all else seems normal, idle, cruise, light acceleration, water temp, etc, you may want to look at:
clogged fuel filter/or really clogged air filter
points need dwell adjusting or replacing if not electronic ignition
timing upset somehow, maybe too far advanced
float going bad, too low
fuel pump diaphragm tear/ check pressure
Bad spark wires, burned by headers? Sometimes, the extra torque and rpm can make a wire move and burn/arc only in that situation
lightly broken valve springs can act up at higher rpm. I've had broken springs behave entirely differently from each other
Let us know more as you troubleshoot and what you find.
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Thread Starter
Melting Slicks
Joined: Jan 2003
Posts: 2,713
Likes: 31
From: Shreveport LA
LA Events Coordinator
Thread Starter
Melting Slicks
Joined: Jan 2003
Posts: 2,713
Likes: 31
From: Shreveport LA
LA Events Coordinator
Update!!! Update!! Update!!!
My trusted and loyal mechanic (been working on my Vette for the past 16years) analyzed my situation and found out my water pump is on "life support". When he grabs the fan, he can rock it back and forth about a 1/2 inch. That's what causing my engine "strain" and vibrate at 3,000 rpm and higher! The engine is running perfectly...he pulled 2 spark plugs and they look as if I had fuel injection system and not a carb. So it's the water pump...which will be replaced tomorrow!! 
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