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-   -   Idling Issues (https://www.cadillacforum.com/forum/big-block-v8s-51/idling-issues-9592/)

79CDVBeast 08-23-2009 01:20 AM

Idling Issues
 
I don't even know where to start. I have a 79 CDV, hence the my name. I recently rebuilt my carb and employeed a friend to help out. Bad idea, he didn't take out the fuel filter before dipping the carb in acid, put the fast idle arm on wrong, and used the wrong gasket when he put it back together. Now that I have corrected all of his mistakes and started adjusting the carb, I got to the part where I reconnect the two air cleaner vacuums, EGR vacuum, and dist vacuum advance. When I get to the dist vacuum advance the RPM start jumping around. I tested the advance vacuum and it holds strong at about 15-20 PSI. I also tested the Centrifugal advance an the OHMS on the pick u coil... all good. I have no idea what else it could be any help would be great.

stomper 08-23-2009 02:55 AM


Originally Posted by 79CDVBeast (Post 33846)
I don't even know where to start. I have a 79 CDV, hence the my name. I recently rebuilt my carb and employeed a friend to help out. Bad idea, he didn't take out the fuel filter before dipping the carb in acid, put the fast idle arm on wrong, and used the wrong gasket when he put it back together. Now that I have corrected all of his mistakes and started adjusting the carb, I got to the part where I reconnect the two air cleaner vacuums, EGR vacuum, and dist vacuum advance. When I get to the dist vacuum advance the RPM start jumping around. I tested the advance vacuum and it holds strong at about 15-20 PSI. I also tested the Centrifugal advance an the OHMS on the pick u coil... all good. I have no idea what else it could be any help would be great.


is it possible that the highlighted job is not completed ?


.

slowroll 08-23-2009 07:53 AM

Make sure base timing is correct. Cadillac big blocks have number 1 cylinder is on PASSENGER side of engine.(unique to Cadillac) If base timing correct, does timing bounce and how much when engine is rev'ed to 2500 rpm? Does car run better withou vac advance? On cars with HEI and vacuum advance - wires for pick up coil can break within insulation causing an intermittent open circuit. The "open" results in a buck/misfire as vac advance cycles. Timing variation in base timing normally is related to excessive play in timing chain, distributor gear(s),or distributor shaft.

79CDVBeast 08-23-2009 10:28 AM

stomper - I basicly rebuilt it again. New carb kit and everything. You might be right thou.

slowroll - Forgive my ingornance, what do you mean by "base timing?" RPMs bounce around when I connect the advance on the dist. It idle smooth (RPMs are stable.) with everything else connect besides the advance vacuum. I tested the pick-up, per my Hanyes manual. And it tested fine.

I'm will play with it some more today and keep you all posted.

Thanks for your insight.

79CDVBeast 08-25-2009 01:08 AM

stomper -your right... I'm going to completely rebuild the carb and flush the gas tank and fuel lines.

Thnanks again for your help and insight.

stomper 08-25-2009 08:39 AM

you do know that there are companies that do nothing but carbs?
just in case there is a need.

personally, I dont think rebuilding a carb is that difficult but they do require exactness upon re-assembly and some of the parts are tiny. all it takes is one little tiny part to be amiss for the engine to run sick.

keep us posted ...

slowroll 08-25-2009 06:50 PM

Good luck with carb - Q-jets are fairly easy to do. Ohm meter will not always tell the tale, Pick up coils do fail when the reading is ok, what is the condition of the wires? Base timing is timing at conditions on engine label under the hood.

79CDVBeast 08-26-2009 05:39 PM

stomper - Yea, I took it to a guy and he couldn't figure out why it was running rich either. He suggested that I have the carb rebuild to make sure that all the lit pieces are where they need to be. He also pulled some gas out of my tank and showed me a very small amounts of lit black specks in floating in it. He said that I should flush my tank and lines. He quoted me a 300.00 price tag for the work.

The Beast will be sitting for a min or two.

I think I might try to rebuild it myself. I've took it apart a hundred and one times already. We'll see.

Thanks for the insight!!!


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