bigredbuick Posted August 21, 2001 Share Posted August 21, 2001 Hi all,<P>300 4bbl, Carter AFB. Carter is rebuilt, exact model that came off the car (4061S). <BR>(Rebuilt by carbshop, not me!)<P>Car idles okay, maybe a little high while in neutral, idles so low while in gear that the car stalls. I get a little backfiring through the exhaust while goosing the throttle in neutral. Acceleration is less than stellar.<P>...and hey, how do I get the threaded rod that the aircleaner mounts on out of the old Carter? I can guess but would rather not booger it up.<P>Slowly climbing out of this pit of inexperience... Thanks for any help! Link to comment Share on other sites More sharing options...
Guest Posted August 21, 2001 Share Posted August 21, 2001 Red,<BR>What is the timing set to?<P>Have you checked the firing order?<P>J Link to comment Share on other sites More sharing options...
bigredbuick Posted August 21, 2001 Author Share Posted August 21, 2001 Firing order is good, time to locate a "Friend With a Timing Light". Then again, I have a 36 year old Buick -logic says to go out and get one of my own and read the instructions... Link to comment Share on other sites More sharing options...
The Old Guy Posted August 21, 2001 Share Posted August 21, 2001 If the car has a 300 engine ,it may also have a switch pitch trans ,and if that is the case perhaps you should check to see if the linkage is set properly. When it is set properly, the switch on the linkage should kick the trans into high stall which will help immensely Link to comment Share on other sites More sharing options...
Guest Posted August 21, 2001 Share Posted August 21, 2001 When did this problem start?<P>Did you take the Carb. to the guy or the whole car?<BR>If you just gave him the carb. then the idle mixture screws would have to be adjusted.<P>Timing is a possibility but only if you have been messing with it. <BR>Along that subject you need to check your vacuum advance, it should be hooked-up to full vacuum at idle (usually an intake manifold sorce) for full advance at idle.<BR>Timing is set with Vac. Adv. disconnected but carb adj. and idle are set with it hooked-up. Link to comment Share on other sites More sharing options...
Guest Posted August 21, 2001 Share Posted August 21, 2001 On the Carter AFB carb, the air cleaner stud is simply screwed in. Use pliers on the mid-section to unscrew it. Link to comment Share on other sites More sharing options...
our51super Posted August 21, 2001 Share Posted August 21, 2001 The Old Guy,<BR>I'm curious to know more about the type of transmission you describe and the high stall position. Trying to learn it all. if you'd like you can e-mail me directly at crindima@hotmail.com so we don't diverge the posting from it's original scope.<P>Thanks, Link to comment Share on other sites More sharing options...
Guest Posted August 21, 2001 Share Posted August 21, 2001 Rob: Random thoughts from a random guy.<P>Change your points, you changed everything else, why leave the old points in there. If you up for another load of spending, nab a Ignitor module in place of the points/condenser and never worry about setting or changing again.<P>I would suggest changing and setting your points(dwell) first, then check and set timing. If you end up going up in timing, your rpm will rise with it, so also check your idle afterwards.<P>Borrow a handheld MityVac or vac pump from a friend and test your vac advance with the dist cap off. Ya look for the baseplate to move as you apply more vacuum to the canister.<P>Once that's done, consider replacing if it needs it. That's what I'm headed for today.<P>A good order of tuning up everything is:<P>Set Dwell (Point gap), unplug vac advance and plug line with bolt or whatever, check and adjust your timing. Plug the vac advance back up and set your curb idle. Then if ya feel up for it, you can try to tune the idle mix. All that it "requires" is a Tach, but a Vac Gauge works tons better. Objective is to set each screw to highest vac reading. Make sure to plug the gauge into the manifold.<P>Good Luck!<P>-S<BR>(from the been there, done that to many times department) Link to comment Share on other sites More sharing options...
bigredbuick Posted August 21, 2001 Author Share Posted August 21, 2001 This gives me a good idea of workflow, thanks! -R Link to comment Share on other sites More sharing options...
FireballV8 Posted August 22, 2001 Share Posted August 22, 2001 Hey CyberBuick<BR>Where in the West San Fernando0 Valley are you located? Let me know I live here too. Email me steveclassic@earthlink.net Link to comment Share on other sites More sharing options...
bigredbuick Posted August 22, 2001 Author Share Posted August 22, 2001 ***When did this problem start?<BR>***Did you take the Carb. to the guy or the whole car?<P>History;<BR>Fuel flow to the carb had always been good (checked at line entry into carb).<BR>Fuel flow within the carb however had been a trickle. Starting required much pumping. The mechanic suggested a rebuild, thought it might be the accelerator pump. I thought about rebuilding, but confidence was low. Thought about giving ito to a local shop, but again, confidence was low. South Florida is dripping with people in garages with tools who think they're mechanics. I decided to look for an identical carb and oddly enough, found one at carbcareusa.com. The core is $30 -I think I'll keep the old unit <P>Relevant info.<BR>The lead connection at the coil was corroded and the wire was falling out. I figured I'd drop a few bucks (turned out to be $60) and replaced the plugs, wires, cap, rotorbutton and coil (points have not been touched). Easy stuff, right? Dropped the hardware in and experienced noticeable improvement. About 50 miles later the car is running pretty rough. When I start it, I get lots of backfiring at the pipes -especially while revving. I did a little online research and asked some "Friends with Clues". The symptoms seemed to point to the accelerator pump. Coupled with previous remarks from another mechanic, I figured I'd wait for the carb.<P>So the carb arrived and was installed easily, and while the backfiring is considerably less, the car still isn't really driveable. <P>*** Timing is a possibility but only if you have been messing with it. <P>Untouched, but probably worth checking, true?<P>***Along that subject you need to check your vacuum advance, it should be hooked-up to full vacuum at idle (usually an intake manifold sorce) for full advance at idle.<P>***Timing is set with Vac. Adv. disconnected but carb adj. and idle are set with it hooked-up. <P>This part is new ground for me. I need to chat with a "Friend with a Clue" about this before I play here.<P>YellowLark, <BR>Thanks. That's what I expected but it's nice to get a "nod" before I start wrenching where no wrench has gone before.<P>-Rob Link to comment Share on other sites More sharing options...
rmartens Posted August 22, 2001 Share Posted August 22, 2001 Rather than wrenching on the threaded rod, run two nuts onto it, lock them against each other, then loosen the rod by turning the lower of the two nuts. Saves scarring the rod. Link to comment Share on other sites More sharing options...
Guest Posted August 22, 2001 Share Posted August 22, 2001 Guys,<BR>That's where I was headed with the timing/firing order question since we are getting "backfiring" etc.<BR>I would doubt that carb settings would cause such behavior.<BR>and there you have my .05 worth (inflation you know). <BR>Jim Link to comment Share on other sites More sharing options...
bigredbuick Posted August 22, 2001 Author Share Posted August 22, 2001 By firing order I'm guessing that you're thinking that maybe plug wires were crossed?<BR>Since the car ran mighty fine for about 50 miles I'm going to feel reasonably confident that they were set up correctly... <P>You can bet that I'll run through it again though. Link to comment Share on other sites More sharing options...
our51super Posted August 22, 2001 Share Posted August 22, 2001 Did you change the points yet?<BR>I'm willing to bet a weeks pay (my wife's ofcourse ) that it's the points. Don't forget to change the condenser along with the points. Link to comment Share on other sites More sharing options...
bigredbuick Posted August 22, 2001 Author Share Posted August 22, 2001 Got a set this morning I have to leave for work in a few, but will try yo drop them in before I go. Adjustment should be easy enough... (famous last words, heh) Link to comment Share on other sites More sharing options...
EstateWagon79 Posted August 23, 2001 Share Posted August 23, 2001 Err, if all else fails BigRed, you should invest in a new AFB. I just changed my 2bbl for a new 4bbl AFB. No modifications were done. I started it up and it runs great. I just took it to a guy to get it tuned and timing checked. <P>That might a thought for you if you don't get that beast running anytime soon. Link to comment Share on other sites More sharing options...
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