1970 OLDS 442 W-30 variable power loss..
March 30th, 2020, 09:09 AM
#1
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1970 OLDS 442 W-30 variable power loss..
Im back again guy's...1970 OLDS 442 W-30 WITH AC...THREE SPEED AUTO...My problem is when im driving between 70 mph and 90 mph, not open the 4brl yet, there is a miss or loss of power that is variable...It feels like im not getting enough fuel...Also when I start from a dead start, I floor it with all barrels open and reach about 5000 rpm's the power drop's down to about 2500rpm...Even though the gas peddle is floored, the power drops and then comes back full throttle... It feels like the fuel is cut off for a second and then comes back...
March 30th, 2020, 10:34 AM
#2
Old(s) Fart
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Sounds like a fuel pressure problem. Could be a weak pump, could be crud in the tank, could be the sock on the pickup in the tank. I'd suggest installing a temporary fuel pressure gauge so you can see what's going on when it happens.
March 30th, 2020, 10:34 AM
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Also when I start from a dead start, I floor it with all barrels open and reach about 5000 rpm's the power drop's down to about 2500rpm...Even though the gas peddle is floored, the power drops and then comes back full throttle... It feels like the fuel is cut off for a second and then comes back...
March 30th, 2020, 11:09 AM
#5
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I had this issue with my 70 Supreme. If I did too much of a burnout, the engine would fall flat around 5000 RPM. Determined the float bowl was running out of fuel, so the quick fix was to lower the float slightly so the float bowl had a tad more fuel. The real fix is a fuel pump that provide more fuel volume.
I had similar symptoms in my '76 TA back in the day. Practicing 0-60 runs using a stopwatch to fine tune my launch technique, the engine ran fine (never got into 3rd gear). Once I got to the 1/8 mile drag strip, the engine bogged before I reached the top of 2nd gear, had to shift to 3rd to limp across the line. Once I got home I discovered a pinched fuel line that was starving the carb under sustained WOT.
March 30th, 2020, 05:15 PM
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cobra, you may also want to consider checking the short rubber fuel line that transitions from the fuel tank sending unit to the steel fuel line that runs inside the frame. If it is kinked up any bit that can cause your issue too. I know because I've had this on two of my cars (70 cutty and 70 442). The problem you describe is exactly what happened in my cases...one replaced, they ran flawlessly....
March 30th, 2020, 05:59 PM
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cobra, you may also want to consider checking the short rubber fuel line that transitions from the fuel tank sending unit to the steel fuel line that runs inside the frame. If it is kinked up any bit that can cause your issue too. I know because I've had this on two of my cars (70 cutty and 70 442). The problem you describe is exactly what happened in my cases...one replaced, they ran flawlessly....
March 30th, 2020, 07:54 PM
#10
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Just last month my 455 4 speed would bog at the end of 1st and or 2nd during full throttle "ONLY" ... then slowly recover -
somewhat intermittent / about 1/2 the time or less - then after about 200 miles of that the fuel pump died !
New Fuel pump last week and now the Qjet can be heard for blocks away !
ALL GOOD
I'm glad the car showed me what was wrong before I broke something trying to fix it -
(as you know the fuel pump is inexpensive & simple to replace)
somewhat intermittent / about 1/2 the time or less - then after about 200 miles of that the fuel pump died !
New Fuel pump last week and now the Qjet can be heard for blocks away !
ALL GOOD
I'm glad the car showed me what was wrong before I broke something trying to fix it -
(as you know the fuel pump is inexpensive & simple to replace)
March 31st, 2020, 07:15 AM
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March 31st, 2020, 07:49 AM
#18
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March 31st, 2020, 08:48 AM
#20
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cobra, you may also want to consider checking the short rubber fuel line that transitions from the fuel tank sending unit to the steel fuel line that runs inside the frame. If it is kinked up any bit that can cause your issue too. I know because I've had this on two of my cars (70 cutty and 70 442). The problem you describe is exactly what happened in my cases...one replaced, they ran flawlessly....
March 31st, 2020, 09:36 AM
#21
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In other words, is there a separate hose or hoses coming from the tank for fuel only...Im just trying to make sure I get the correct hose for fuel and not the vent...
March 31st, 2020, 01:36 PM
#22
CH3NO2 LEARN IT BURN IT
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My 400G block would nose over too. I troubleshot everything. I had the problem for a while before I found the solution.
Try this simple thing first...Remove the rubber end out of the fuel filter reinstall it and road test.
Try this simple thing first...Remove the rubber end out of the fuel filter reinstall it and road test.
March 31st, 2020, 01:40 PM
#23
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Good idea..But I did do that...Same problem...
April 1st, 2020, 07:49 PM
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Another test I did....I ran in it 1st gear @ 5000 RPM'S for 20 seconds and it did not falter... No loss of power... So i tried another test from stand still. And it lost power about 4500 RPM then came back up full throttle....So im guessing something to do with the forward G forces???? Could this have something to do with the float????
April 1st, 2020, 11:12 PM
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Another test I did....I ran in it 1st gear @ 5000 RPM'S for 20 seconds and it did not falter... No loss of power... So i tried another test from stand still. And it lost power about 4500 RPM then came back up full throttle....So im guessing something to do with the forward G forces???? Could this have something to do with the float????
April 2nd, 2020, 05:21 AM
#29
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April 2nd, 2020, 07:58 AM
#31
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It's also the first word of a popular phrase. Usually immediately followed by "Da Fuq?" when you actually find the issue and resolve it. 
I'm with Joe P on this one, as it sounds like a lack of fuel delivery issue so start with that temp fuel pressure gage. Either your pump ain't getting and keeping it there when you need it, or there's a restriction. Assuming your float level is good and all your fuel passages are clear.
I'm with Joe P on this one, as it sounds like a lack of fuel delivery issue so start with that temp fuel pressure gage. Either your pump ain't getting and keeping it there when you need it, or there's a restriction. Assuming your float level is good and all your fuel passages are clear.
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