check points and dwell. I recomend a quadrajet metering rod and jet kit. I had to get one once i got all the goodies for my 350
My backfire while accelerating was resolved by swapping in a new (rebuilt) distributor fror $35. MARK
Are you talking about changing timing inside dist. with adjusting points or removing bolt and turning the dist. Thats all I have adjusted is the points. My intial timing was 0 when I first checked it. I was told to change it to about 8 degrees advanced, made no difference. how would you know if the vac. advance had failed or would it even matter. It's idling fine, does'nt seem like much is wrong but its got me confused o No:[/QUOTE] I meant that you should try adjusting the initial timing by turning the distributor. To check the vac advance you can use a vacuum pump to on the canister, then if the advance is bad it will leak and not hold the pressure. Check the mechanical advance by leaving the vac advance off and reving the motor a bit from idle. Use a timing light while you do this and you should see the timing rise up from the initial setting.
If you have a points Dist then you have to make sure that the points are set dead on either with Dwell meter or with a Feeler Guage. if you are going down the road and you start to push the gas down to the floor and you start to get popping thru the carb then it could be that the points could be way off. If your car is at idle in park and you stab the gas about halveway to the floor even one quarter throttle will do it and it backfires then you need a little more gas going to the carb at that point with more on the pump shot. The vacuum on the dist. can be checked with a timing light by just touching the gas a little the mark on the balancer will move quickly. Then you disconnect the vac. line that goes to the Dist. and the mark will move slower or not at all. Your best bet would be to get rid othe points in the Dist. and go with electronic parts as these can go right inside your Dist. with no problem. Or you can get a Dist. from a 75 up 350 this has electronic ignition you will have to change your wires though and run a r45ts plug. Make sure that you have no vac. leaks as this will make a mess of things. You can spray wd40 around the carb to see if the idle changes. If it does then you have a leak. Also I forgot that points Must be set First then the timing. Points will change the timing. Hope this helps.
Well the problem end up being my camshaft. The lobes on it were worn and some of my valves were not seating. Putting a Poston 114 cam and replacing springs, lifters, push rods, oil pump, rings and all bearings. Should run very strong.
HTML: Well the problem end up being my camshaft. The lobes on it were worn and some of my valves were not seating. Putting a Poston 114 cam and replacing springs, lifters, push rods, oil pump, rings and all bearings. Should run very strong. IT's funny you mention that. I started this thread and i been just looking at everybody's responce. which where all good posibilities, but today i found out exactly that: Camshaft went bad, the lobes got worned out and of course the valves where not seating right. So now i just got off the phone w/ TA and order the TA212. I will get it tomorrow and see how it works out.I'll let you guys know. Thanks everybody for your responce. Marvin :TU: :TU: :TU:
HOw to prevent this After posting my previous post, i started wondering. What would make the lobs on a camshaft wear out? Was it not installed properly? How can i prevent this issue happenig again? the old cam, the one that went bad was just installed about 1 month ago. thanks
Yes! Improper break-in procedure, OR poor oiling of the engine can cause premature cam failure. I had a gentleman bringh me a '68 GTO with a freshly rebuilt motor, that had only 1,700 miles on it that had darn near all the cam lobes wiped out! Upon further inspection, he also had a wiped out engine! What happened? Well, after a close inspection of the engine, which involved a complete tear down, I discovered that the rebuilder (AKA "Butcher") hadn't engaged the end of the oil pump driveshaft properly with the oil pump (which is driven by the distributor) and apparantly ran it for a number of minutes without discovering his mistake. Once the problem was discovered, and rectified, he thought all was well. Not so! The now compromised bearings , and cam lobes, were doomed! As the car was driven, the wear was accelerated a thousand fold, and killed that sucker in short order. The moral of the story? ... Especially with Buick 350's and 455's, is make sure your timing chain cover (which IS the oil pump, for all intents and purposes)is in good shape! AND drill prime the engine before start-up. I do this on all engines that it is applicable to, and as a professional mechanic, I have done quite a few. Oh yeah, lots of cam pre-lube too! Lube your shaft, and it will never let you down! :Brow: Uh, that doesn't sound right, does it?---Zach
Nice car Zach by the way! Yeah, you'll want to use new lifters and new valve springs if you have the extra cash. I would upgrade the ignition as well while your at it. Glad to hear you found the problem!
