Its already been mentioned. Most likey your cam went flat or you have a lifter that is not rotating in its bore and hanging up. Time to pull the intake and check out all the lifters for wear. Not running an oil with ZDDP?
I agree with a few others - Bad Cam lobe. I made a good buck back in the 80's and early 90's replacing cams in 305 chivvys and they all ran like you describe and stink like you describe.
Newest oil change was penzoil 10w30 I'll check it again later today, with the valves adjusted, and check dwell etc. If a lobe went flat would that not show on the vacuum gauge?
Might want to change the oil again and see if any debris comes out with it. That might give you an idea if the cam lobe got wiped out.
Yes. <HR style="BACKGROUND-COLOR: #e5e5e5; COLOR: #e5e5e5" SIZE=1> I forgot to add the vacuum gauge scenario's address above. http://www.secondchancegarage.com/public/186.cfm
I had the same problem with my SBC, tried lots of stuff. It had a tune-up a year earlier by the sellers mechanic so I didn't try anything which I inally did: changed the points (new a year earlier), plugs (new a year earlier, but wrong for a SBC) and ignition wires and it's run fine for a year now.
yes it would show or yes it would not show? I will check that again today, but yesterday it fluttered for about an inch but smoothed out steady, but low. It does have a radiacl cam in it tho
Yes, the vacuum gauge will reflect changes and needle movement. Check the site and run the scenario's to see what compares to your gauge. Sorry about leaving all the stuff off, busy morning already....
Have you done a compression test. if not I would start there and also a leak down test. Sounds like you might possibly have a blown head gasket between two cylinders. a compression test will tell you this and you will have low compression in two cylinders next to eachother. I have had this problem on a few cars with the same symptoms you are having. also I have had a cam lobe go flat on a 350 and had some similar symptoms. although it would start slight and get alot worse over time as it wears. when you said that it sat for an hour then just started and ran terrible thta made me think that you popped a head gasket. If it is a bad cam lobe dont be tempted to just stab another cam in there and go motoring. Pull it apart and get out all the metal and find out if possible why you lost that lobe like low oil pressure to that area... Hope this helps Eric
One of the first diagnostic tests that I always perform is to pull each plug wire one at a time while the engine is running. Use some heavy insulated pliers. If the missing is isolated to one cylinder as in a wiped cam, bad wire or fouled plug, it will be easy to spot. The bad cylinder will not change how it runs with the plug wire on or off. That will locate where to look. If no dead cylinders are found then you are probably talking about something random like ignition or fuel distribution. Harder to find but you can forget about a wiped cam, bad plug or plug wire etc. You have proven that the problem applies to all the cylinders and not just 1 or 2.
Get rid of the points and change out the Mallory to an MSD8360 plug-n-play distributor. Bad points or dwell settings will have you chasing your tail.
Could be... especially if the needles and seats are a little gunked up. The pump that screwed the pooch on mine was also a Carter (non-adjustable type). If that is your problem, you will want to change your oil. All the extra gas will end up in the crank case. It could have it thinned out enough to be why you've got oil in the distributor, too. Don'tcha just hate cars sometimes...??? Good luck. Hope you get it figured out. JOE
Half the carb not working? Try putting your hand gently over the carb at idle see if the idle picks up or improves........
compression test is as follows on a cold engine. 1,3,5 were 165 7 was 170 2,4,6 were 170 and 8 was 165 break for dinner then check valve lash.
Looks like you're making some progress with the compression test out of the way. I wouldn't get too excited about tossing the points distributor right now. I'm liking too, Tommy's suggestion to pull one plug wire at a time to see if a single cylinder is the culprit. I'm guessing as well that you know that points are set with the rubbing block on the high point of the distributor cam. Get em set with a way too narrow gap and the engine appears to have a carb problem.
This also makes me wanna bet its too much fuel pressure. At higher RPM you're using all the extra gas that its pumping. You might just turn the key to IGN without starting the engine and see if its ******* gas down the throats with the throttle closed... and then slightly cracked open. The accelerator pump will squirt some, but then if you have too much pressure, and its ******* past the needles, it will drip... maybe even from the 4-bbl side... JOE
What makes Pennzoil bad? I've run it in everything from 500cc dirt bikes to lawnmowers as well as my cars. Never had a problem with it - sludge etc. that always seems to be dragged up and commented upon. My engines have always been clean when I opened them up. In fact any quality oil made in the US should do ok if you change it regularly. I'd like to hear your experiences with it.
update. Dwell for the mallory dual point is supposed to be 33 plus or minus 2 and I have 30.7 valve adjusted and sounds the same, idles ok and somewhat smooths out at 3-4000 rpms before that she misses with some valve chatter, almost sounds like an exhasut leak. Vacuum guage is steady at 5 inches, which is close for the cam and was the same reading when running good. looks like the one in scenario 3 but a lower reading. Drops to 0 then moves way up when revved. no backfiring but missing or shuddering...
I don't want to hijack the thread, but i had a bad experience with Pennzoil. I bought a Pontiac 6000 new, from a dealer. I faithfully Changed oil and filter every 3000 miles. It was the first car i had seen with a programable reminder for oil changes on the dash i set it up for 2900 miles to remind me and always changed it. It was my wifes car, driven like a typical woman drives, it didn't get abused. ( Irarely drove it) At 53,000 miles the oil pressure was less than half of what it was when new...and dropping. Thinking (hoping actually) it was the oil pump I got a new one in it. that lasted about ten miles then the pressure would drop to zero at idle. i pulled the engine and found all the mains and rod bearing were wiped out. I had a friend rebuild the motor for me and we found the rest of the motor looked great. He asked what oil i ran in it. I proudly told him "Pennzoil". he shook his head and said "run something else, almost anything else". He builds and races cars, from a F.E.D to a pro stock Dodge and said that Pennzoil breaks down very quickly..like after one p***. "Comes out like water" He reccomended Wolfs Head. I was talking about this with my son in laws dad who runs one of the best car shops in the area and he said "I wouldn't oil a doorhinge with Pennzoil." His reccomendation was Valvoline, which i have run since the Pontiac incident. Another Shop owner was more polite, but also indicated my bearing problem was because of my oil choice. Up till that problem I swore by Pennziol. Now I hear horror stories about it.
First thinks first, check the basics,if it ran fine when you parked it then started it and it ran bad,you can eliminate a lot of mechanical stuff, cams dont go flat by sitting still, valves dont burn when its prked etc,check the basisics, sample a pop bottle of fuel,let it sit for a while if theres water in it itll settle out,bad seals or a bad pvc will pull oil into the plugs under high va***,like idling, slowing down for your drive way etc, did you pull a plug wire one at a time to isolate the problem to one cylinder? This will narrow it down if its a couple cylinders or effects all of em[for instance a carb or timing problem effects all cylinders, a mechanical or plug will only effect a couple} dont change so many things at once you create more problems! Throwing parts at it never works! Just my 02
Plug wires are new, but the PCV thing has me thinking since it could cause the oil in the dizzy as well. I have one of those mr gakset pcv breather combo in my valve cover... I want to change plugs tomorrow, have not pulled a wire, casue it is tight and my manifolds get hot and I hav not figure out yet the best way to do it, of cousre I could just pull one at a time alternating and start it each time to check...
5 inches is not much va*** unless yo have a huge cam , check the timing, did you loose a va*** cap offf the carb or intake? It could be a bad lifter not pumping up especially if your using penzoil, but again you have to isolate the cyl, and i doubt thats it. Are your condensors different with the new dist? Ive seen plenty of bad new ones, they can make all sorts of crazy things happen, and they often go bad when you restart the engine, if you have 8 lbs of fuel pressure thats a little high but if its a holley youll have gas everywhere and probably a fire by now so its probably ok, hard to say without being there.
Oh yeah you got to pull wires with it running, youl never tell if you have to restart it evry time, wont be very accurrate, get some plastic kids toy pliers at the dollar store, pull em at the dist end if you can-im a drivability tech- my rulr is be consitant and scientific youll get there faster
Timing chains jump when you shut the motor down, usually. Unless you have gears in that maybe its time to check cam timing. Two years is about what you get out of a timing set with bigger cam. Hope it's something simpler though.......good luck with it.
Yes chains and belts do skip when shut down but unless you have the ny lon gear from the 60,s and you dont,a sbc has to have the chain sawing through the cover to be llose enough to skip, i have once saw a broken keyway on the bottom gear, but it wouldnt have run this long.
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