327 Small Block Idiling Questions.

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  #21  
Old 06-06-2010, 09:36 PM
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Again, keep advancing the timing a little at a time, then take it for a drive and listen for marbles (pinging). As soon as it gets to that point, back the timing off a touch.
1. 1100 isn't terrible for an automatic. And true, you may be compensating for a rough cam. Get your kickdown cable hooked up.
2. Hooking up your kickdown cable as you just did in step 1 will take care of your premature upshifting problem. Btw, the "kickdown" cable is more than just for passing gear.
It tells the trans your throttle position, and that coupled with the vacuum modulator is how the trans decides where to upshift. Full manifold vacuum to the modulator is correct.
2. When the gas pedal is to the floor, the throttle blades in the carb should be all the way open. If not, you're missing out on a lot of performance and your linkage needs some work to correct it.
 
  #22  
Old 06-09-2010, 08:21 AM
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1. Ordered transmission kick down cable and bracket should have it tomorrow from Heartbeat City.

2. Im using the full vacuum port as shown in the link below to go to the transmission. I'm getting about 11 on the vacuum gauge at idle in park. Is that the right port?
http://www.holley.com/data/Products/...99R10219-3.pdf

3. Adjusted the accelerator so I have full range of motion with the gas peddle now.


Existing issues.
-Vacuum secondary does not kick in at all. I put a small zip tie on the rod under the diaphram and drove it (pegged it) and zip tie didnt move. Could this be related to a timing issue still or Vacuum leak? If there is a VAC leak what are some methods to test the intake? Old owner said he had to make his own mark on the harmonic balancer as the new one is afer market, so I will recheck the timing again at TDC.

-Shifts through 1-3 quickly not allowing for engine to reach higher RPM. Transmission kick down cable on order. Kick down cable wasnt hooked up before with old carb and didnt shift like that. What would cause that, to much vacuum from carb, not enough?
 
  #23  
Old 06-09-2010, 09:59 AM
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1. good
2. Yes, full manifold is right for the trans. But I'd say your vacuum level is most likely the problem. Most modulators need at least 15 in. of vacuum to work correctly. Do you have a factory type of modulator, or aftermarket? Some aftermarket ones are adjustable so you can change the shift points. Remove the vacuum hose on the nipple of the mod. and look inside to see if it has a small screw slot. If so, it's adjustable. If not, you'll want to get an adjustable one. Turn clockwise to raise shift points, and counter-clockwise to lower.
3. good again

Vacuum secondary: are you sure the zip tie wasn't too tight? Did your Holley come with different secondary springs? You may have to play with different ones to fine tune it. That's probably the only feature I like about Quadrajets... the adjustable secondary wind-up spring.
 
  #24  
Old 06-09-2010, 06:32 PM
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Finally getting some where. Decided to start over and adjust everything myself. Started with the mixture, and then adjusted the floats. By adjusting the mixture correctly i was able to get to a vacuum of about 15 in Hg instead of the 11in Hg. Car now grew a pair and can an least move. Still shifts early while driving, but im happy its moving again and will play with that tomorrow once I get the trany linkage cable and will check the modulator. Also, secondary kicks in on carb (put the yellow spring in awhile ago as its the lightest one.

Car does backfire a bit when hammered on, so I need to double check a few things. Timing maybe? Still not 100% on if I'm running to lean or rich, so I will check that too. Any other things to check that would cause that?
 
  #25  
Old 06-10-2010, 12:48 PM
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Adjusted timing slightly again. Minimized back firing to almost nothing. Still have about 1/2 sec hesitation when hitting the gas. Is it normal to be fine tuning the timing like this? Drive adjust, drive, adjust, drive.
 
  #26  
Old 06-10-2010, 04:46 PM
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Originally Posted by rkiefer2
Adjusted timing slightly again. Minimized back firing to almost nothing. Still have about 1/2 sec hesitation when hitting the gas. Is it normal to be fine tuning the timing like this? Drive adjust, drive, adjust, drive.
Well, since you have no idea where your timing mark is supposed to be on the dampener, I'd say yeah.
Plus, not all engines are created or treated equal. Compression ratio, fuel octane, mileage (carbon buildup), air temperatures, and barometric pressures all play a part on how much or little the timing can be advanced. Even what works on your neighbors similar engine may not work the same for you. That's where you experiment to see just how much advance you can get away with.
Setting it "by the book" is only a guideline.
 
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