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I rebuilt my 302 H.O.in 99 for my '83 Mercury(Crimson Cat)Capri. I didn't bore her over, I just freshened her with a 351 cam,carb,manifold,honed her out redid the heads and new internals and have had problems with it loading up ever since. It would start great in the mornings, I would let her warm up, she would be great. After a while though she would start giving off black smoke. If I were 90 and drove her 30 miles an hour in the city and 45 on the highway the answer would be dah, but lets face it, I am like my Grandmother...65 to 75 or stop. I use to be able to just go out on the Highway and let her loose until she stopped smoking but that however didn't work after a while and she on mornings started rough and bogged really bad and died. I tried chugging her up to the Highway to open her up but she just stopped running altogether one morning and I haven't driven her since and it is driving me nuts not being able to drive her anymore. Now I kept her in top form doing all maintenance myself and when this started up I changed plugs,wires,timing,carb.needles,( Edlebrock carb. 750 and mani.)and played with the gas and air adjustments to no avail.
This didn't happen before the rebuild and that is the only thing I didn't do. Yes I tore her down but a friend did the rebuild for me and I put her engine back into the her (and no bolts were left over lol). The same friend though took all the smog parts off( we live in a non smog state). I've even taken her in for leak down checks and vacuum tests and she is health as a Mustang. Any ideas? Signed Stanger sick.