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...

 

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.

 

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.

 

Kudos to you both for smoky burnouts and 5000 RPM shifts!

I haven’t done either of those since high school, might be time to revisit

 

Pretty sure you meant to say you raised the float level so that more fuel remained in the bowl.

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.

 

Thank you very much!! This gives some good ideas....

 

Yes, thanks for the correction.

 

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....

 

Thank you!! You know you might right because from time to time I can smell gas around the gas tank after a drive....If that hose is leaking, it also might be getting air in the line...

 

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)

 

Fuel filter old?

 

No sir...I just replaced it....

 

Any breaks in the fuel line that had a patch rubber hose installed? If using fuel with alcohol present it could be making the rubber swell and block things.

 

I will look this weekend and see..

 

Is it a stock points distributor?

 

Yes..But upgraded to pertronix III..No more points...

 

If I remember right the Pertronix needs a full 12v, does it have that and not running through the resistor wire to supply power?

 

Yes..Full 12 volts..

 

All great suggestions here so you have a lot to check, GL

 

Are these rubber hoses considered vented fuel lines???? Or is there an actual rubber fuel line for fuel....Not vented...

 

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...

 

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.

 

Good idea..But I did do that...Same problem...

 

Well I found the gas smell problem...There is a white over flow valve in front of the gas tank this is spewing a little gas at the top....Is this normal???

 

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????

 

Add to the list...dirty pickup sock in the tank. If it wasn't coincidenctal it could be related to Gforces???

 

good thought..

 

Was that 20 seconds at WOT? Likely not as that would result in something bad happening. There is a lot more fuel demand at WOT than just at a constant RPM.

 

What does WOT mean???

 

WOT = Wide Open Throttle

 

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.

 

Problem solved...Bad fuel pump..Did a pressure check and hardly nothing came out..Put new one on and works like a champ!!