hesitation at 3k and up in 3rd gear?
11-28-12, 05:43 PM
#1
hesitation at 3k and up in 3rd gear?
I have a hesitation at @ 3k rpm and in 3rd gear. I just rebuilt the carb but had the problem before. Car screams through 1st to 7k rpm, through 2nd to 7k rpm no problems no hesitation. But when shifted into 3rd at @ 3k rpm motor almost acts like it has a rev limiter and won't go past 80 mph in third???? I thought it was starving for fuel so I just installed a new Mallory fuel pump. I also have noticed a loud screeching noise while at wot. Don't know if the two are related. Car also has direct fire ignition. A friend thought the screeching sound was a lean condition but I don't think so. Any ideas?? thanks
11-28-12, 07:14 PM
#3
It definitely sounds like fuel starvation to me. Detonation sounds like a pinging, so the noise may be a belt slipping. In any case, you should probably stop doing that. Did you change the filter when you changed the pump? 3rd at 3k RPM is 80mph in your car?
11-28-12, 07:23 PM
#4
yes. two new fram g2 filters. one b4 new fuel pump and one b4 carb. The Mallory pump is the low pressure high volume pump for foreign cars. yes secondaries are opening. The noise comes in when I go WOT. say cruising in 2nd then when WOT there is the screeching/metaic sounding noise. I also thought fuel starvation.
11-28-12, 07:50 PM
#5
I'd get a jug and do a volume test. The pump may be good, but not getting the proper voltage. Or there could be a clog in the line or the pickup from the tank. If the system turns out okay, then it could be a sticking float needle or improper float level. I'd only suspect that if the carb had been tampered with recently. Messing with the floats is not recommended.
11-28-12, 09:06 PM
#6
I rebuilt the carb. I know the needles have been sticking a little at first.I had the hesitation problem before the rebuild which is why I rebuilt it. When the rebuild didn't fix it I got the Mallory pump.I wired in a relay for the fuel pump so I know all that is ok. I have always had 2 fram g2 filters. One b4 carb and one before pump in stock location so I don't think there is a clog. I used the old pump to pump all gas out of the tank because the car sat for 3 months and it filled the containers in a couple of minutes. That was with a pump that flowed 40gpm. The Mallory pump is 70 gpm.
Trending Topics
11-30-12, 06:10 PM
#8
fuel passage way inside or before the carb is blocked and you are starving the motor of fuel doing 7krpm wot runs, broke my original 12a the same way you are describing 6-7 years ago. I second that you are wasting time draining the fuel, I would not personally do that after three months, I would only drain if it has been multiple years the gas has been sitting.
11-30-12, 08:59 PM
#9
turns out the high rpm hesitation was a coil. I have direct fire. one coil per L1& L2 and one coil for trailing through the distributor. One coil went bad today and the trailing was on its way out. A friend who is a rotary guru put a timing light on each plug wire and discovered the bad coils. These were Summit Racing coils that were maybe a year old. Also... Gas with Ethanol goes bad in as little as a month. Ethanol is hydroscopic which means it attracts moisture/water. It was the WORST thing they EVER added to gasoline. It destroys rubber fuel lines and plastic floats. It also REDUCES the fuel mileage ANY car gets PERIOD. Now we have all these farmers dependent on growing corn for Ethanol production and it is ****! It will never go away! Now gas stations are selling "Ethanol free" gas at $4.00 a gallon. Do some research on Ethanol.
Thread
Thread Starter
Forum
Replies
Last Post