New Eddy Carb,Coil,plugs,points,cap,wires and still a buck and stumble? UPDATE!!

[Mfr426]

I'm just about ready to flat bed my car to an auction! I have a fresh 383 with good compression, a stock 4V manifold and a brand new Eddy 600 CFM and still this heap is stumbling. The motor runs super rich and I cant figure it out? I've swapped out distributors, have new plugs, new wires and even went so far as to buy a $250 NEW Eddy AFB to resolve this issue. I've put in new points, cap and rotor too. I've timed it from 5 degrees to about 15 degrees, rechecked the firing order and still I have bucking and backfiring thru the carb?

I'm beginning to wonder if the knuckle head that "freshened up" my motor last year put the timing chain and gears on and did not line up the marks correctly. When I did it I was dead sure that the marks were lined up. They took the motor apart to do a new main seal and bearings for the crank. I am beginning to wonder if they put the gear set on wrong?

What would be the symptoms of a timing gear installed incorrectly? Would the motor even run? I have a miss and it's just not smooth. When you drive it it almost seems fuel starved but I think it's actually overly rich. It breaks up at higher RPMs and really missed and pops. That tells me timing but I cant figure it out.

Any help would be great. Thanks all in advance. I live about 10 minutes from Ray Barton and am tempted to take it to him to tune. I have these visions of taking the front end of the motor off to double check the timing marks. I really dont want to do that as I have the car show ready at this point.

Mike R

[Shakey]

I really dont want to do that as I have the car show ready at this point.

Mike R

Mike,

I wish I could help but I will leave that to the more experienced members here.

What I will say though - go is far more important than show.

If you have an engine tuner close by and are stuck, spend the time and money and get him to help you solve the problem once and for all.  You have come this far - correct?

P.S. - I know you are only teasing me when you mention getting rid of your beautiful car.   

[dodge freak]

Are you sure the spark plug wires are all in order. If even just 2 are cross it will cause problems. Yes the engine will run if the timing chain jump 1 or 2 teeth, I have seen it on a old motor, can't remember how it ran but it was week. I though it needed a new cam and when I went to change it I seen it. What about the spark box, not sure thats it but have you change that. You would think a cam that was off a tooth would show week compression, To me its alot of work to get the front cover off , but who knows. Maybe that is it, but you might be wasting alot of time. Not sure if somebody else would get it going without spending alot of money, more than $250. Sorry to hear all the trouble you are having. Not sure what to tell you, if you feel up to it pull the cover and if the chain has more than 10,000 miles on it you might as well change it any ways. I wounder if you change the spark box and that is not it and IF the chain is line up right if you should not go ahead and pull the camshaft out. Have you look at the valves with the covers off and make sure they all go up and down.

[RD]

when you pulled your old plugs, were all of them carbon'd up or were some of them clean or lean/burnt looking?

[Chryco Psycho]

an engine with the timing chain out 1 tooth will run but it is usually hard to start & runs poorly , , I have seen some engine run terrible just because of a bad cam choice even with the chain on right , have you tried doing a compression test ?

[Mfr426]

OK, I've had a night to sleep on this. Yes I did a compression test. It's 120 across ALL cylinders. The cam is a MP cam for the super commando/magnum engines so it's a stock cam in those motors. That's why I picked it since it would be a known to work combination.

Old plugs looked typical (tanish) but were VERY carbon fouled. I then replaced them with new plugs (NGK). The motor has about 50 miles on it as does the new timing chain so I know it's not worn at all.

I too hate to pull that front cover off. The motor is painted up and looks great and I have no leaks.

This has no spark mod and is a stock ignition.

[greenpigs]

Could it be 180 degs off?

[dodge freak]

Hey thats a really good point, he means the dist. is a half a turn off. It is firing on the exhaust stroke not the power. You can pull the plugs out and turn it by hand with your finger in the hole, you can feel the compression build on the power stroke. When it is coming up look at the dist rotor and look what Cly. is going to fire, it should be that one. If its on the other side that is the problem.

[BigBlockSam]

 

[mikepmcs]

And you have followed this to the letter right?

http://www.sweptline.com/tech/engine2.html

I haven't yet but i will very soon!
good luck!!!

[Mfr426]

UPDATE...I thought of the 180 off on the dist and rotated it and tried it 180 out. No luck the car would not even start (which is a good sign).

I put on the new carb and changed the fuel filter and timed it again and it is FINALLY running better. I have minimal smoke on acceleration but the car still lacks  power. I've been all over this thing. I pulled all vacuum lines and plugged them to prove that the vacuum tree didnt have a leak but that did not change anything. I swapped out 3 dist caps, 2 distributors, a set of plug wires, a coil, etc and although it runs better it still lacks the power this thing should have.

I had a place that is close by (and does Kohrs Kustoms final setup) do the front end setup and some final brake work a few months ago and I think I am going to take it to them and have them do the final tuning. I also live about 5 mintues from Ray Barton Racing Engines and am tempted to take it there. I'm not sure I can afford his labor costs though...



I'll update as things change. I'm SUPER swamped at work/home/car etc and had NO internet this weekend so my posting was very limited.

Thanks all for the help. Stay tuned to see if we can get this pig tuned.

MIke

[greenpigs]

Did you make sure it is able to get WOT? or to say the carb opens all the way.

Also I would try and blow the fuel line clean with compressed air..could have some junk in the line + it is free to try.

[dodge freak]

:i agree: Yeah make sure when you floor it the blades are straight up. Thats a small carb. and if the secondary are not opening and its only half way open that maybe it. I had to take my gas pedal off and bend it so my holley open open right. You can also adjust it a little by the carb. At least its running good, maybe change that oil this week, to get the gas out of it.

[Mfr426]

I put a new fuel filter on it on Sun and back drained the line. I did not check that the throttle plates were opening all the way since it is a brand new carb. It almost does run like it's only a 2bbl. I changed the oil and filter this weekend too. I should be able to see those open throttle plates without taking the carb out correct?

I just made an appt to have "the pros" look at it on thursday.

[dodge freak]

Just have somebody step on the gas all the way, engine off , and check if its back all the way by your hand. Does not matter brand new or not, the cable may be too long for it. In the good old days that happen a lot of times, some even left the factory that way.

[Mfr426]

Hey dodge freak, that's a thought! I adjsted the throttle cable to get this thing in. I wonder...hmmmmmmm...

Now if I could just find some time to work on this thing...

Thanks for the idea.

Mike R

[grouseman]

Do you have Full or Ported manifold vacuum going to the distributor?  And is the vac. advance can on the distributor stock and known to be good?

grouseman

[Mfr426]

Well, it's been a week since I posted on this situation so I better get everyone up to date. It appears to have been the vacuum line connection to the base of the new carb. I had it at the full vacuum intake (on the drivers side) and the shop switched it to the intake on the passenger side. Looks like the new guy "grouseman" hit the mark. 

The mechanic then timed it to about 10 degrees after checking to make sure we were really at TDC indicating the timing gears we're installed correctly. They were. He also adjusted something on the trans to allow it to downshift as needed. We both agreed that I needed a different throttle cable and I just got one from Mancini yesterday (24"). I have not put it in yet but am hoping that it will take care of my inability to get the secondaries to open on full throttle.

I spent $160 for labor but honestly I was beating my head against a wall for a few days so it was a steal to me. I did have the vacuum line at that port initially based on the directions that came with the carb but I reread the directions and thought I had it wrong so I moved it. Apparently I did not read it correctly? When I have time I will take the instructions back out and reread them.

The bottom line is that the car idles well, has better oil pressure and has more "zip" off the line. I drove it on Sunday for about an hour at all speeds and I'm now quite confident with the way it runs.

Thanks all for the ideas, comments and suggestions. I was a PITA for a while but I'd pay the money again to have an old timer who worked on these cars when they were new troubleshoot my car.

[grouseman]

I used to be Mopartom on the old board.  I'm not 'new' by any stretch. 

Glad you got it fixed!  I know how frustrating it can be. 

[Mfr426]

New, old...I'll take it!

Yep, it was really pissing me off. Now I can move on to my other punch list on the car.

Thanks Tom!

[dodge freak]

$160 is not bad at all. Good to hear its running good, good luck on the throttle cable. If you can't get it right take it back, remember this is the fun stuff stuff now. Whats you going to do with the other carbs? Sell them on e-bay or try to put them back on and see if you can get at least one running right too. Its nice to have a spare carb so if it acts up again you can swap carbs and see if that was it.