Mike, Here's a couple Ideas to try. 1. Make sure you are getting full throttle travel with the pedal pushed to the floor. Not likely the problem, but a good thing to check. The reason for checking is because Ron Wester ( screaming Yellow D) had an Acceleration problem. WE discovered with the pedal to the floor he was only getting Half throttle at the engine. I discovered the pedal arm was bent towards the floor which limited travel. It was easy to bend it back to normal. 2. It could be possible your Ignition Is breaking down at RPM. Or the Advance is not working. You a Mechanical and Vacuum advance here. ( Low Probability) 3. Sever idle hunt is probably a vacuum leak. Does it ever settle down? Check W pipe gaskets and idle air tube O-ring in the bottom of the Airflow meter. 4. Since your successful REDLINE RPM test was without the air cleaner on Check to see if the air box is unrestricted. Although an air leak down stream of the airflow plate would cause a very LEAN situation. (low power and back firing). A restricted Air filter would cause low power RICH condition. But, I would also expect to see a some what sooty exhaust. Good luck Dennis --- In dmcnews@xxxxxxxxxxxxxxx, mike clemens <rmclemns@...> wrote: > > Okay, some history first, since several folks have asked. Josh's car was originally sold in New York and was driven there for many years. Then it made it's way to California and then to Oklahoma and now it resides in Arkansas. My best guess is that before I started working on it, it has probably been 10+ years since it last ran under it's own power. > > Here's where we are today. I utilized many of the ideas that the List provided to try to solve the backfiring and bogging between 3 and 4000 rpm, but one hit the nail on the head. Thanks to Ken K, he suggested I push down on the air metering flap, while at the same time, giving it throttle. RPM's went all the way to red line-----yea. He also gave me two things to look at----a vacuum leak and possibly the cat plugged. > > Well, when I snapped off the O2 sensor, I decided to go ahead and pull the cat, since I was already there. I was able to remove the cat and when I looked inside, I saw a mud dauber nest! After about 5 seconds of trying to figure how they got in there, I came to realize that it really wasn't a mud dauber nest at all, but the cat had overheated and melted the 'guts'. Since the cat was useless, I gutted it and reattached everything, including a straight pipe in place of the muffler, just to see if this fixed my problem. > > Answer----nope. I still can't get full throttle and now the idle is hunting both cold and hot. (550-950 rpm) > > I'm down to this last thing to get BB running 4.0 and out of my shed. Any ideas will be greatly appreciated. > > Mike TPS 1630 > ------------------------------------ To address comments privately to the moderating team, please address: moderators@xxxxxxxxxxx For more info on the list, tech articles, cars for sale see www.dmcnews.com To search the archives or view files, log in at http://groups.yahoo.com/group/dmcnewsYahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/dmcnews/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/dmcnews/join (Yahoo! ID required) <*> To change settings via email: mailto:dmcnews-digest@xxxxxxxxxxxxxxx mailto:dmcnews-fullfeatured@xxxxxxxxxxxxxxx <*> To unsubscribe from this group, send an email to: dmcnews-unsubscribe@xxxxxxxxxxxxxxx <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/