I finally got my '69 put back together (307, powerglide) and it idles and cranks just fine, sounds normal. But sometimes when i hit the gas, the car is so slack and has no pickup. Other times, i hit the gas and it jumps up fine (mostly going downhill). As soon as I pull a hill though and put the gas to the floor, the thing tachs up like crazy and goes all of about 10 mph. It acts like it is pulling a 5 ton trailer! Is it the transmission, carb (2 barrel) or what. Timing, idle and air/fuel mixture is fine. The car just will not go when it is pullin a hill. Also, sometimes from a stop, it tends to start to die, but a quick tap of gas remedies the problem. Any halp would be appreciated. Thanks

What you really need to do is go through the basic tune up items and either replace them if yo haven't done so already, or go back and check all adjustments and settings. Start from square one. The firing order is 1-8-4-3-6-5-7-2. The dwell on the points, if you still have points, should be 30 to 35 degrees. The spark plug gaps should be around .032. Adjust the mixture screws on the carb to obtain the smoothest idle. Set the timing according to the sticker on the radiator cover, if it's stil present, otherwise, set the initial timing at 8 to 10 degrees BTDC with the vacuum hose removed from the advance chamber on the distributor. Don't forget to reconnect it when you're done.

If you've done all of this already, then you need to check the fuel pump pressure. You should have 4 to 7 psi. While checking the fuel system, you need to get the car up on jackstands and look at the fuel lines from front to rear. You want to pay particular attention to the fuel lines above the rear axle, where you have rubber hoses that connect between the lines on the frame and the fuel tank. They are notorious for cracking and allowing air to be drawn in the system. If all of this checks out okay, then you may need to pul the fuel pickup tube and sending unit out of the tank and replace the fuel sock.

This sounds more like a fuel starvation problem, but you need to diagnose it by starting with the simpler items first, and work your way up to the more complicated. I'm not ready to lay the blame on the transmission just yet.

I agree with Randy, what you are describing sounds like a fuel probelm.

When was the last time you changed you fuel filter.

Larry

I changed the fuel filter last week after I added my rebuilt carb back on the motor. With my last carb (4 barrel) I could never completely lean out the motor. That carb sometimes burned just straight gas. Could that have completely destroyed my spark plugs? As far as I can see, my fuel line is intact and the carb is getting plenty of fuel. The reason I brought up the transmission is because, I'm just adding ATF as I go because I could never find the quart capacity for a powerglide. Do you think its something as serious as a valvetrain or timing chain problem? Or is the thing just in need of spark plugs that arent covered in black buildup like my current plugs?! Thanks

Like I said, start over with the basic things first. You should go ahead and install new plugs.

Another thing you need to be aware of is the possibility that the exhaust system is plugged. A critter could have crawled in the pipe while the engine was apart and built a nest. You may dropped a rag or a tool down into one of the pipes while you were reinstalling the engine. Or, and this is a possibility if the car still has the original factory exhaust, one of the pipes may have collapsed internally. GM experimented with double steel wall pipes in the late sixties and early seventies as a way to prolong the life of exhaust system components when leaded gas was still in use. The problems occured when the inner wall would collapse due to the different expansion rates of the inner and outer walls. On the outside, you wouldn't see a problem. But on the inside, the collapsed inner wall would sometimes completely obstruct exhaust flow.
The quickest way to check for this is to loosen the pipes at the manifolds and take it for a very quick test drive. Avoid the temptation to to wring it out with the open manifolds because you can warp the exhaust valves by revving the engine and then snapping the throttle shut. Slow and deliberate throttle movements are you all you need. Get into it easy and back off easy. All you want to do is see if it will run normaly with the pipes dropped from the manifolds. If it does, then you need to visit your local muffler shop and have a new exhaust system installed.

I'm gonna change plugs and plug wires tomorrow just because the plugs are probably shot and the plug wires arent the right length and some are starting to get fried by my headers. (As far as the exhast pipe thing goes, I had dual stainless steel pipes installed in Oct. 2000). When I first crank the car when it is cold, I notice a black condensation coming from the pipes which looks like a mixture of maybe water and carbon buildup? I shouldnt neglet to mention that, the car was sitting from August 2001 to Feb. 2002 without being cranked and the same gasoline in it for 6 months. Fuel system cleaner needed possibly to completely blow all that carbon out of the mototr? Thanks

That black looking water is actually normal. Lots of cars do that.

Keep us posted.

Could having plugs with carbon deposits all over them and plug wires that are partially burnt on a few of the boots cause a bad hesitation where I can only pull a hil doin' about 10 mph?

It could quite possibly cause the engine to run on seven, six, or five cylinders. Yes, when you kill cylinders, you'll lose power. But again, those things should be on the list of basic tune-up items.

New plugs and plug wires did fix my problem. I dont have a clue as too whats up! Anytime I try to ease into the gas, it acts like it is just flooding like crazy. Stepping on the accelerator does nothing but make the thing die. Is it float level or what? I put everything back together like it was when I got the car. I'm so frustrated from putting all this effort into it and nothing getting better. 'Bout ready to sell it and get something new that you dont have to play with as much.

RaidersGSF, you said you rebuilt the carb recently- where is the float height set at?Also have you checked around the carb for vaccum leaks? While rebuilding my roommates dad's Buick Riviera we had the same prob-idles good,step on the gas and it would try and die, hard accel same thing.Turned out to be that his intake manifold was so corroded that it was porous in 3 PLACES! Under a heavy load it would suck air through it.Edelbrock Performer RPM cured all. Maybe you could be that lucky too http://www.chevelles.com/forum/biggrin.gif

Sounds vaccum related to me if not a carb problem.WHy was it sitting so long? Just curious....

I didnt rebuild the carb, I bought a remanufactured one from Paddock parts. I assumed that with a few minor fixes, I could bolt it on to the stock intake and be good to go. Is there anything that I am forgeting to do. As for the intake, it seems good and stable. Could debris in my 6 month old fuel cause this? It was sitting so long because I just started college back in Sept. and simply didnt have the time or money to mess with it. I guess I'll just have it towed to a shop and let them chase down the problem.

on my 2-25-02 post at 10:57 pm, I meant to say that plugs and plug wires did NOT fix my problem.

Sounds to me like you might be low on transmission fluid. Have you checked the dip stick in Park with the motor running?

Yes, the ATF level barely registers on my dipstick. I have already put 7 quarts in the thing, and I dont know how much more to add. When going up a hill, it just feels like the transmission is not grabbing nearly enough to apply torque to the rear wheels. I say this because i think I have analyzed the carb to death and cant find a problem.

Seems to me if your engine is revving up (taching like crazy?) but you're going nowhere fast, then it must be transmission related, unless you're leaving clouds of blue tire smoke behind, not likely with your engine (no offense intended).

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Cecil Hawkins
San Diego, CA
1971 GMC Sprint
The Project (http://www.chevelles.com/showroom/Cecils71Sprint1.jpg)
All I need is time...and some $$$ (http://www.chevelles.com/showroom/Cecils71Sprint2.jpg)
"Tourist, go home! And take someone with you!"

Anybody know off hand just exactly how many quarts of ATF to add to my powerglide. I completely drained the fluid and changed the filter too.

If I remember correctly a PG needs 9 qts. Start it in park and keep adding until it reads full...FRED

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