Hi, I've been trying to work out the bugs in my '68 Colony Park with a 429. It has had the holley carb rebuilt. It idles okay in park (a little high I think) but idles rough in gear. It is sluggish when accelerating but it does handle 65-70 mph fine. Today, I tried plugging the vacuum advance and it drove a little better. It still has a rough idle. It does have a Pertronix I ignition module and it did have a broken ground connection on the negative terminal on the ignition coil. After driving about 300 miles, I swapped to a new coil and it ran much better but still had idle issues. It is now running a bit more rough again. I checked the voltage at the coil (+) terminal with the key on and car off. It read about 7 volts. When I checked while it was running, it was jumping between 12v and 15.8 volts. I used a valve cover bolt as a ground when doing this check. When I first fire it up cold, it has a bit more performance. It becomes a bit more sluggish when driven for a while. I am bought it it ran smooth. I am not sure if the full force of a tow truck trying to jump start until smoke began to appear did some damage to the Pertronix, coil, or voltage regulator. I know the coil was damaged. Any tips would be appreciated. Wayne SavedURI :Show URL SavedURI :Hide URL http://www.stationwagonforums.com/forums/newthread.php?do=newthread&f=8
Did you set the carburetor up properly after the rebuild? The air/fuel mix is set to base line spec in the rebuild. That will let it run, but you need to adjust the mix carefully when it is installed. It sounds like it is actually running too lean once it is warm. Cold, the choke is allowing it to run better as the mixture is richer.
It does feel lean when hot. I have a 180 degree thermostat and after driving a while, the needle is about 188 even though the outside tem is about 50 degrees. The temp is slightly higher with the vac adv plugged in. It does feel like there is a steady misfire at times especially when coming to a complete stop, being in gear, and revving. I was wondering if the voltage regulator could be overcharging the ignition coil/ Pertronix? I thought the coil vots should have stayed around 7.0 and not read 12-15v. There was alot of voltage applied to get the wagon jump started. The starter relay was close to cooked and there was smoke around the AC compressor (where the negative jumper was grounded to). After installing the new coil, my idle improved but has deteriorated once more. I am going to pull out the spark plugs to inspect them. If I need to place new ones on, what should the gap be for a '71 stock 4v 429 with Pertronix? How much torque should be used to tighten the plugs? Thanks, Wayne SavedURI :Show URL SavedURI :Hide URL http://www.stationwagonforums.com/forums/newreply.php?do=newreply&noquote=1&p=280863
I don't know anything about the Pertronix, but I do know the Ford carbs, and they are easy to tune, once you know the trick. For the gap, I would figure it needs to be 50/1000, the same as the electronic ignition Ford engines. The rule of thumb for tightening the plugs is tapered plugs go finger tight plus 1/8 turn, and the ones with a washer go finger tight plus 1/4 turn. It is a matter of feel as much as anything.
Mike, Thanks for the tips. My knowledge base on Fords and carbs are rather limited at present. The P/O had installed a Holley that that did get rebuilt about 2 months ago. I will try and figure out how to make the mixture richer. SavedURI :Show URL SavedURI :Hide URL http://www.stationwagonforums.com/forums/newreply.php?do=newreply&noquote=1&p=280983
At the base of the carburetor, on the front, there will be two screws. Those adjust the air fuel mixture on the idle circuit by moving the metering rods in and out. IF you can reach them with the breather on, do so. If not, remove the breather. You need a flat head screwdriver, somewhere around 1/3 of an inch wide. Start with the passenger side, and turn it in until the idle starts to slow. Slowly turn it out until the idle is just starts to slow again, then turn it in about 1/8th of a turn. Do the same on the other adjustment screw. If the idle starts to climb too high, lower the idle using the idle adjustment screw on the throttle linkage. When you have done the second side, repeat on both screws again, until the idle is as fast as you can get it on that adjustment. When you are done, turn the screws out about 1/8th turn to allow for the restriction of the breather. Set the idle properly with the adjustment on the throttle linkage, put the breather back on, and take her for a drive. The other thing is to make sure there is NO vacuum leak, particularly around the base of the carb and the base of the spacer. If you suspect a leak, but aren't sure where, use an unlit propane torch, turned fairly low, and run it around and over any place you suspect. If the idle goes up, you have found your leak. I am betting that helps a lot.
Mike, Thank You for the instructions. I will give it a try after the new year. Thanks, Wayne SavedURI :Show URL SavedURI :Hide URL http://www.stationwagonforums.com/forums/showthread.php?t=28833
You're welcome, Wayne. I know that adjusting carburetors is a knack, verging on a black art! Hope the tips help.
