Help! The Sprint has a severe hesitation when accelerating, to the point of stalling frequently. The accelerator pump seems to be working OK, checked for vacuum leaks and couldn't find anything obvious, PCV valve OK, choke isn't stuck. It seemed to be running lean so I turned out the idle mixture screws a bit which seemed to help, but they're now like, five and a half turns out and it still wants to fall on its face. I rebuilt the carb last year, so it shouldn't be a problem. The car idles great, it's only when you get out on the road with it that there's a problem. Please help me out here, I really want to be able to go cruisin' with the wife...
Timing is 12 BTDC (Duraspark II ignition) and I gapped the plugs at about .045, and the fuel tank has been cleaned out and sealed. I took the fuel filter off and it doesn't appear to be clogged.
reply I just had the same thing happen to my carb.. I'm not saying yours is the same problem but it sure sounds just like what mine was doing.. I took it apart and put a kit in it and still no good. Right off idle it would sound like the timing was way retarded and the engine would fall on itself until you were out of the idle circuit. I was to the point of buying a new carb when a 72 year old friend of mine told me to rev the engine up and put me hand over the carb and kill it... I'll be darned if it didn't work... :bananaman he said it was like a vapor lock in the idle circuit.... carb works fine now.. hope this helps .. I had to do it a couple times
Also check your vacuum advance on your distributor. Pull the vacuum line off and the dist.cap and plug a vacuum tester and check for smooth operation. I have seen wrong or sticky advances cause this before. Just something else to look for.
Vac advance AH, very good Rob.. Have seen that before.. I hope he finds it soon.. The suspence is killing me.. Also, just a wild hair, but check the butterfly shaft for any play.., that can cause some wierd stuff too... It will idle ok till you give it gas and that will pull the shaft and create a vacuum leak..
Thanks everyone for the tips so far. Believe me, the suspense is killing me too. It was pouring rain here for most of the day and I had some "honey-do's" to catch up on, so I'll get back at 'er tomorrow and report back.
And the winner is... ...it appears that a bad vacuum advance was the culprit. Thanks to all who responded!
