I got issues!

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Jonnylightening

Jonnylightening

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Ok guy got my car finished but now im having issues. My motor is a stock bottom 318 with the following:
EQ heads
Summit .454 lift cam
Stage 2 mag springs
Gasket matched eddy performer intake
Street demon 625 carb
Double roller timing gearset
Stock manifolds
Factory electronic ign. (Non lean burn)

Cams broken in and i have the timing set at 34* at 3k rpms. Car starts and idles great, Free revs good, and drives good at a cruise. Whenever i try power braking and let off the throttle it tries to die, same as whenever i kick it down it tries to die and misses? Any ideas??
 
T-port sync, and fat accelerator pump,come to mind.Need a line-loc.But;
What rear gears?
what stall speed?
What cam specs?
what idle-timing?
Vacuum advance hooked to sparkport?
 
Gears are 2.72s i think but i have n 8.75 with 3.91s
Converter is stock
I didnt get the idle timing, i read some to let it fall where it falls total at 3k was more important?
Vac advance is hooked to ported vac port
Cam is Summit SUM-K50052

It runs decent at a light cruise from stop and gradually get into it but if you leave at wot it pops and carries on n tries to shut off
 
Jonnylightening said:
Gears are 2.72s i think but i have n 8.75 with 3.91s
Converter is stock
I didnt get the idle timing, i read some to let it fall where it falls total at 3k was more important?
Vac advance is hooked to ported vac port
Cam is Summit SUM-K50052

It runs decent at a light cruise from stop and gradually get into it but if you leave at wot it pops and carries on n tries to shut off
Click to expand...

Sounds like the secondaries of that carb are opening before the engine can take it. Did you tighten the air valve yet? Can you disconnect the linkage so the secondaries will not open, to rule that out?
 
Jonnylightening said:
No i did the cam swap in the car. I put the engine at TDC and lined up the marks
Click to expand...

Well, there's one mistake. That cam isn't designed to stab in straight up. It should be 4* advanced. With no degree wheel having been used, you don't know if it's really straight up, or not. It could even be several degrees retarded.

You've said where total timing is. Where is initial?
 
I havnt messed with the carb other than idle mixture screws to get most vacuum (12lbs). I can try n take the linkage off the secondaries
 
I would probably start by disconnecting your vacuum advance and set your timing at 3K - 34 -36 degrees. See what that gives you for initial. Then test drive. Eliminate some variables then you can hook the vacuum advance back up and see what it's actually doing for you.
 
And I forgot to mention you have no idea what your cam timing is.

Pull the driver side rocker box off and see what the #1 cylinder rockers look like at cross over. If they are off the seat the same, the cam is close to straight up. If the intake is further open its advanced. If the exhaust is open more, it's retarded.

You can degree a cam in the car. I have done it so many times I can't count. If you have the skills to install the cam, buy the tools and learn how to correctly degree a cam.
 
Put that stock unit up for sale here on the board and let one of these guys that think they are so great buy it... Then put in a HEI conversion unit or an MSD setup...:popcorn:
 
Jonnylightening said:
I cant remember wat the initial timings at. A few people said to let it fall where it falls
Click to expand...

The 70's called, they want their tuning approach back!!! Total timing is NOT the best way to set up a car driven on the street.

If it's still advancing after 3K, it's not timed correctly anyways!

Mopar Electronic Ignition System - Mopar Muscle Magazine


I'll guess the engine will want 14-18 initial timing, maybe up to 20. It should pull more than 12" at idle.
 
You said you had 34* at 3000. Later you said it was 36*@3000.You also said it was still advancing. So in other words you really don't know what your power timing is. You have to keep revving it up until it stops advancing, whether that be 3000, or 3500 or 4000 or(hopefully not) some whatever rpm.And then read it, and then change it back to 34* at that rpm that the timing maxed out at.
Then you can say with authority, the power-timing is 34* at suchNsuch rpm. Then you bring it back to idle and read that. And then you can say your idle-timing is suchNsuch at suchNsuch rpm.Then we can formulate a correction plan.

With 2.72s, and a stock TC, I think you may be expecting too much. Saddled with these handicaps you can move your cam any where you like and it won't make a hill of beans difference.

Now getting back to your carb; handicapped by gears and a low-stall,You are really gonna have to tighten up the air-door. Not just to prevent a bog, but to also prevent the beast from going rich, until the engine can take it.
Then timing; Once you know what you actually have, and it's backed up some, maybe it will smarten up.And there may be other calibration changes required.

But from your description of how it doesn't perform, there's a good chance that the carb calibration is off and/or the timing is excessive, or there is a mechanical issue. Or the rotor is needing re-phasing, or the coil is dying, or the plugs have been overheated one too many a time.Others have mentioned most of these things.
We need to figure out why the power ain't there.But first we need to rule out issues with spark and timing.
So 1).please list your cam specs
And 2) probably do a compression test.While the plugs are out,
3)give them a good inspection.
And 4)do a stall-test on the TC.
And 5)what A-body do you have?
 
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The timing is obviously not right. You need to get it timed right FIRST, then move on to the carburetor.
 
While the hood was open i put it in gear and it easily went to WOT and once the secondary door opens it bogs to barley idling i hav to pump the throttle to bring it back to idle. I readjusted the secondary air door til the flap closed then gave it another full turn counter clockwise plus worked my way up to an aditional turn a 1/4 at a time. Still the same problem
 
No 1), it's not supposed to open in neutral/park. That's your problem right there! When it opens, it sends a huge fuel dump into the manifold. And then it is practically flooded. Of course it will want to die when you back out of the throttle.
Now go tighten that thing up!

No 2),12/36@ 3500 is pretty close.At least close enough, that we don't have to worry about it being over-advanced and wanting to detonate itself to death.
 
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How much more can i go? They recommend not much more than a turn from factory which is basically 2 turns counter clockwise from the door just closing
 
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