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post #1 of (permalink) Old 11-24-2007, 11:41 AM Thread Starter
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update still need help

Okay on my 88 yj with hei distributor and mc2100 carb......When I am sitting at idle, I can rev it up and hold it it reacts great......When I am in drive and punch the gas hard it dies.. is the carb related? Vacuum advance related? Kickdown related? Or tranny relateD? Any suggestions on how to fix it? I know they have adjustable vacuum advance diaphrams but would I need it since it is only doing it in drive and reverse??? I have the timing set at 6 degree btc and my carb is set at 2 turns out....Thanks in advacne..

Last edited by onecrazyblackredneck; 11-24-2007 at 02:49 PM.
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post #2 of (permalink) Old 11-24-2007, 03:39 PM
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I'd check your vaccum lines.. Also re-check your timing with a light and a vacuum gauge, Once you get it where you have the highest vacuum you should be really close then you can use the timing light to fine tune it... Sometimes the suggested timing isn't best for that specific engine... Depending on wear & tear and or and modifications... After that double check your curb idle, set if needed, and then readust your fuel/air mixture... Use a timing light for this and put it on RPM's... You should only tweak an 1/8" turn going from one to another... Watch your rpms... It should increase a little, if it increases the rpms a lot reset your curb idle and repeat... Honestly, I do one at a time... I wait until she's at temp from idling, I'll turn one fuel/air mixture screw until it chokes the engine and then I'll do 1 full turn, then do the other side, then I'll fine tweak each side 1/8" turn, maybe a little more... Once you hit where the rpms don't increase then you're pretty close... I normally turn it back about an 1/8" turn... Sniff the exhaust And then I'll check the throttle response and take it on a test drive... After it cools I check the plugs to make sure everything is good. I'm not saying that this is the correct way but it's what I do and I haven't had any issues yet.

Last edited by [email protected]; 11-24-2007 at 03:42 PM.
post #3 of (permalink) Old 11-25-2007, 12:31 AM
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Is the timing advance working on your HEI? Could be that the advance is not working correctly and your just not noticing it without a load.

Is this the only hammer you've got?
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post #4 of (permalink) Old 11-25-2007, 08:46 AM
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Have you thought about a Crane HEI Advance kit? It's not a bad product.
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post #5 of (permalink) Old 11-25-2007, 09:14 AM Thread Starter
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i am going to try that, I am not sure my advance is working properly..
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post #6 of (permalink) Old 11-25-2007, 02:25 PM
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If it's advancing too fast, or too much it could create those symptoms. Using the wrong type vacuum can also do it.

Easy way to check it - simply disconnect the vacuum line to the distributor - then drive it.
Without the vacuum it's running on just the mechanical advance curve (power curve) - it'll run fine there - just not get the better mileage the vacuum will give you.

Obviously if it makes no difference - it's not an advance issue.

Make sure you are NOT using manifold vacuum for the distributor, manifold vacuum gives the wrong curve.
Use ported vacuum.
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