what would be your diagnosis?????

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RustyRatRod said:
They are Edelbrock heads, right? Do they recommend a particular intake gasket, I wonder? Would not hurt to check into that as well.

Try to cover all your bases, cause you don't want to do it again......and I know you want the thAng fixed. lol
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Yes, edelbrock heads. I want to ride real bad this summer.
 
duster360 said:
Yes, edelbrock heads. I want to ride real bad this summer.
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I bet you do. I don't blame you, either. That's all the more reason to get the magnifying glass out and really smoke things over good. Just try not to get in a rush. You'll find it.
 
duster360 said:
You gotta spill the beans on the receipt.
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Yes.... They have little cells in them (think NCR Carbonless). I just did this at work to diagnose a sealing problem on a machine..... Worked like a champ....

I have never seen or heard of the trick on intakes since I saw it myself but it is a useful and simple way to check to make sure the port are properly aligned for fitment. Mine was off minimal but he took the information he obtained from that test and milled the intake for me that evening. Problem solved which is very similar to yours. My motor was more of a Race Application but none the less a similar problem...

The guys name was Dave Barbarian and anyone in the Richmond area who knew about Hoenes and Eanes will know the name. He was crazy smart and was killed in an automobile accident back in the 90's.
 
on my 340 I cut the head gasket side of the J heads .010" and decked the block .010" - did NOT cut intake side of heads and no cutting on the old LD340 intake. the cutting was done just to clean things up. I like my intake gaskets squished tight, 1213hp fel pro printoseal. the intake was a tight squeeze down, had my 275 pound friend stand on it when I bolted it on-15 years and no leaks
 
duster360 did you get this worked out? What was the diagnosis? Had to have hip surgery. Non weight bearing restrictions. Mine has not been touched. Everyone I know is wrenching and showing me time slips. Bastards. Lol. Want to get back at it badly. Hope you got it worked out.
 
WA71swinger said:
duster360 did you get this worked out? What was the diagnosis? Had to have hip surgery. Non weight bearing restrictions. Mine has not been touched. Everyone I know is wrenching and showing me time slips. Bastards. Lol. Want to get back at it badly. Hope you got it worked out.
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I always try to fix things myself and I usually get it done. But this time it for some reason it is beyond my knowledge and I am frustrated to say the least. The time has come for me to let someone else worry about it. There is a well known guy in our area that works on all these old mopar musclecars. That's all he works on. So I have decided to let him do whatever it takes to get it going again. I want to enjoy the car this summer, it has been down for 2 years and I am ready to ride. I will post back here when the car is fixed. It will be a couple weeks before he takes possession of it, but I will post back here when done.
 
have you tried pulling one plug wire at a time while running and listening for a change, that may locate the problem if its one cylinder
 
Hi duster 360 , I have been reading this thread for a while and can see you have had some good information and I can see there is still a problem so I would like to throw something at you. You mentioned in the beginning that your leakdown is good and the compression test is good and this helped you determine the valve adjustment is good. Your 165 cranking compression indicates the camshaft is probably installed correctly and the leakdown is good however if your valve adjustment is to tight it would not always be verified by the above it would be by your vacuum reading unless the valves are actually hanging open then the other 2 tests would reveal that. When you shut your engine off the lifter will bleed down to some degree and spinning it over doing a compression test may not create the same situation as it would when running. After watching the video and the vacuum guage it would be my guess the lifter pre load is tight ,I would look at the ones with the oil on the back of the valve to verify , you might have already verified they are fine and I missed it but that is what it seems like to me , either way I hope you get it resolved and get to enjoy it.
 
If I back the throttle idle adjustment screw all the way out so the butterflies are closed the engine still runs. It will go from 900 rpm idle to 300 rpm. If I turn the drivers side idle air adjustment all the way (passenger side still backed out 1 1/2 turns) in it will still run, but very slowly. If I adjust it back out 1 1/2 turns and the go to the passenger side and turn that adjuster all the way in it will die, but slowly, takes about 10 seconds or so.
 
I may have missed something, but is it backfiring at all? It looks like it is missing or un even compression from the video. I have never ran adjustable rockers on a MOPAR, but had a small block Chevy in the past. I once over ajusted the valves, and it ran crappy. I am thinking because the valve timing essentially gets "slowed down" for lack of a better word. the cam is pushing againgt tighter resisitance, and who knows if the valves are truly closing completely. Did you try adjusting the valves running? It can be messy, but if its hydraulic lifters, back the rocker nut off till it starts tapping, then run them down till it stops, plus another 1/4 to 1/2 turn. If you static adjusted them, you may want to try a "engine running valve adjustment". If it is solid lifters, you need to set valve lash with feeler gauges. I know setting the valves running is an oily mess, what I used to do is make a shield out of tin foil, and set it over the oil holes on the rockers. You can bed the foil to stay in place and still access the bolts. You may be doubting this adjustment, but if you know what you are doing, it is pretty quick and painless. its worth a try. Like said, I have been there and done that with my SB Chevy, it happens. one more thing Id like to point out, if your cam is mild and not that lopey, your vacuum reading is 5-8 in hg too low, I'm thinking 15-18 in hg, should be coming up on that guage.
 
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I agree with you on the Hg reading. No backfiring. It just won't smooth out. I can push the throttle slowly ( sitting in the driveway ) and even at 2500 it is still shaky. Once it hits 3000 it is like you put a shot of nitrous to it, the engine wants to rev quickly. I have also had someone else adjust the valves with the same results. I am considering doing as someone mentioned earlier in this thread, to back the adjusters off a 1/4 turn and see what happens. I checked and someone else checked (to back up my results) the lower end and do a leakdown and compression test and neither of us found an issue.
 
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