Need help with an original challenger r/t, asap

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moparmade43

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I know this isnt an A body, but since I value your opinions and the engine is the same, I thought I'd ask the same question I asked on another forum:

Guys, I have an original 340 challenger r/t, 1971, with 32,000 original miles on it. Recently, there has been a ticking noise coming from under the hood, and I have finally pinpointed it I think, using a wooden dowel and lots of patience. The tick is loudest using the dowel on the timing mark directly beside/behind the balancer. The balancer and pulley are original. My question is, if a balancer is bad, would it cause the noise I am hearing? Any other ideas. It could be chain/sprocket, but with that low mileage I'm skeptical, especially as the rest of the timing chain cover does not produce the same amount of noise as right beside the balancer. By the way, this is not a knock, like a rod, but a very distinct tick, almost tinny sounding. At first I thought lifter, but the sound is very week at the intake and heads. Any help would be GREATLY appreciated, I am trying to get it fixed for a big show on sunday. My buddy has the new challenger and we were going to park them side by side. Thanks in adance.

Will
 
Take the fuel pump out and check it out. Look at the timing chain through the fuel pump inlet and see if you see any fresh "scrub" marks on the chain anywhere. If you can't see the chain directly then use one of those little mirrors. It could be numerous things but taking the timing chain cover off you have accomplished a few things. You check out the fuel pump,timing chain, harmonic balancer, oil slinger, timing chain sprockets, water pump etc.. This is what I would do.
 
Sounds like the fuel pump driver!! or what ever you call that round thing that is round and moves the fuel pump arm has some play and is getting loose
and losser.
 
Thanks for all your help, It was in fact the timing chain was shot. The chain was SCARY loose, and the cam actually jumped a tooth or two, but I got all that taken care of and fired up, and all is well. Thanks for your advice. Now on to the second part of the problem. The car surges at cruising speed and has a lack of power, and really falls on its face when you get on it, especially at high rpm. I think it is fuel pressure, as it doesn't do it nearly as bad if you rev it up to redline with the car parked. If it was timing or electrical, it would do it at all times I would think. Also, I have eliminated the carburetor as I have put a known good rebuilt thermoquad on it, and no change, although it starts much better now. I'm thinking the sending unit sock is shot, and is starving the engine. It is the factory pump, lines and tank, never been opened up. The lines are 5/16 also, which is probably not helping if the engine is starving already. I fabbed up a fuel pressure gauge into the cockpit, and after dinner. I plan on takin it down the road and seeing what it reads. I know you want fuel pressure around 7-7.5 psi, but my questions is should the pressure drop as rpm's increase, or should it be able to supply a steady 7 psi throughout the rpm band? Thanks for any help, this is the last thing to get this car road ready!

Will
 
timing marks may be off. They can idle and run very well in neutral and wont have any power. Seen it more than once. Crank as much as 2 teeth wrong and timing dialed up to compensate.
 
I am thinking it should stay almost steady, But I am not a tec.
Did it do this before the timing chain and gears where changed out?
 
Yes, the car has run like this for the last year and a half or so. That is why we haven't been driving it. The timing chain and sprockets were just a noise that just happened, but the car runs exactly the same now as it did before the swap. I am suspecting that it is fuel. I just drove it and the longer you hold you foot into it, and the higher it revs, the worse it runs and the lower the fuel pressure drops. It hit close to 4.5 psi a couple times at high rpm when it was really falling on its face, plus I had about five foot of fuel hose from the carb into the cabin, so I'm sure actual pressure was much lower than what it was reading. Am I correct in assuming the problem is fuel starvation based on this?


Thanks, Will
 
Alright guys, I got the sending unit out and the sock looks very nasty, it is almost black and I'm sure it is probably the original one. I want to replace it before I put the sending unit back in, and the unit is fine, so I'm not buying a new one, but I can't find one at any of my local parts store. Have any of you bought one from your local dealer or parts store, or i
s this a year one part?

Thanks
 
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