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Discussion Starter #1
Hi Fellas,

I have a 350 0.040 trw flat top,186 casting 2.02 1.60 64cc,comp cams 280h hyd flat tappet,weiand stealth intake,600 cfm edelbrock 1405 orange step up springs,msd 8365 ready to run dist with blue springs and the 18 deg cent advance bushing.Its in a 68 4 spd camaro everything is fairly fresh comp test was 180 psi on all 8.The car runs pretty strong but I cant get it to idle for horse duckey at 18 deg initial and ported vacuum without the thing dieseling at shutdown.Coolant temp is 160 to 170 idle at 800 rpm to 900 rpm 8 in vacuum almost rock steady needle.I do get some response from the mixture screws and when I pull carb to check transfer slot it seems close to 0.020 but dont have measuring equip.Car likes to idle at 25 deg initial do i need to drill the throttle plates or further limit the cent advance somehow ....

thanks for your thoughts
 

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Nice combo you have and it reads like it runs pretty well.

I think it s horse puckey rather than horse duckey......LOL

I would probably change the vacuum advance from ported to full time. This would allow reduced basic timing at start-up and shutdown.

If all else fails, you can leave the trans in 4th gear, foot on the brake and let out on the clutch when the key is turned off. Dieseling hates loads.

Are you sure the mark on the harmonic balancer and the timing pointer match with #1 TDC? Hopefully you don't have a '69 or later h/b with a 68 or older timing cover/pointer.
 

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Engines diesel because of retarded timing and too lean an idle circuit. You timing definately isn't retarded so if the idle isn't too high it is probabily lean in the idle circuit.
 

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Longrod406,

I have a very similar setup, and had the same problem. I played with everything but it would still happen. Either I would have to set the idle REALLY low, or it would diesel. I finally changed the step-up springs (EDL part # 1464) to the seven inch spring and it never happened again. Have you tried the 7 or 8 inch springs (pink or plain, respectively)?

It sounds like you already changed them (I thought stock were yellow) so you probably have the kit. Sorry to waste your time if you already tried the others, but that's what did it for me.
 

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You know how sometimes you can have a problem and after awhile it will just go away. Well, my '69 would do that same thing. Its a mild 350 and automatic. When running 87 octane, it done it all the time. I started running the 92 in it and it stopped all togather. Later on in a pinch, I put the 87 back in it, and it started again. After I ran that tank out, I put the 92 back in and have never had the problem again. This could have absolutely nothing to do about the octane, but it sure seem like the higher octane helped. Just my .02 worth. Hope it helped.
 

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Discussion Starter #6
Hey thanks everyone for sharing your thoughts.I found a small vac leak at phenolic spacer to manifold got new felpro on top and bottom of spacer no more vac leak reset everything and so far no diesel.Next dilema is to find the tapping or ticking sound i hear in car while driving after she reaches full temp definately not exhaust
leak its intermitten which i dont understand all ehaust sealed tight!!!
 

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Could be the wife's finger nails tapping on the dash wondering when you are gonna quit messing with it and just take her out to dinner
 

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When the key is turned "off" there is no longer any voltage getting to the ignition, so retarded or advanced timing would make no difference, since there is no longer any spark to the spark plugs.

Usually, the fuel is being ignited by hot spots in the combustion area, hence the term "dieseling", low octane fuel will make the condition worse.
 
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