PINTO CAR CLUB of AMERICA

Welcome to FordPinto.com, The home of the PCCA => General Help- Ask the Experts... => Topic started by: boughtabobcat on June 22, 2014, 12:27:35 AM

Title: 78 Bobcat wagon 2.3L distributor question
Post by: boughtabobcat on June 22, 2014, 12:27:35 AM
So, I've been experiencing an issue with my 2.3L hesitating under acceleration (it has a duraspark 2 distributor) - I'd recently replaced the timing belt, set the timing to the recommended 20 degrees as stated on the valve cover, and gotten the vacuum lines figured out (I think?!). And I finally used my loyalty points from the zone to get a free timing light. I plugged the vacuum advance at the dashpot itself and also the port coming from the carb, started her up, shot the light on my marks and discovered I was at about 22 degrees. No biggie, I just turned the dist. and got it back to 20, and then I wondered, "did I just set it a little off in the first place, or did it somehow loosen up and change itself?" so once I got it set dead on, I left the light on my marks and goosed the throttle a couple of times to see if it was moving itself and to my surprise, when it was just the mechanical advance, the timing actually went BACKWARDS about 4 degrees before advancing! Well, I watched it do this a couple of times, noted that at idle it was still showing 20, then plugged the vacuum advance back in and goosed it some and it advanced, no backwards movement at all. My question is this - is that normal for the mechanical advance to retard before advancing? Or is it a sign I should take the distributor apart and clean/lube the weights and springs? (Actually I can find a remanufactured dist. on ebay for 38 bucks, so I'd just put a new one in... :) ) I'm not too well versed on a duraspark 2, so I don't know if that's normal - I know I'm not! Lol! Any help is appreciated!
Title: Re: 78 Bobcat wagon 2.3L distributor question
Post by: amc49 on June 23, 2014, 06:40:49 PM
Only difference in the distributors is one is electronic and other is not, the advance works exactly in same way.
Title: Re: 78 Bobcat wagon 2.3L distributor question
Post by: boughtabobcat on June 23, 2014, 11:18:32 PM
What two distributors do you speak of?
Title: Re: 78 Bobcat wagon 2.3L distributor question
Post by: 74 PintoWagon on June 23, 2014, 11:56:56 PM
What two distributors do you speak of?
Ons has points and the other is electronic, the Duraspark is electronic no points. Is your vacuum hooked up to ported vacuum or full manifold vacuum?.
Title: Re: 78 Bobcat wagon 2.3L distributor question
Post by: amc49 on June 24, 2014, 02:00:07 PM
Mechanical advance only going backwards slightly at initial swing says worn parts to me............ ......
Title: Re: 78 Bobcat wagon 2.3L distributor question
Post by: 74 PintoWagon on June 25, 2014, 12:48:39 PM
It shouldn't retard, I'd take a look inside sounds like worn parts but it may be a simple fix..
Title: Re: 78 Bobcat wagon 2.3L distributor question
Post by: amc49 on June 25, 2014, 04:47:18 PM
May well be fixable without a new distributor as he says. There is no retard in mechanical advance. Looseness of parts allows it to fumble around until rpm high enough to throw the weights out positively to stay in place.

Duraspark II is simply Duraspark I with more coil current.

Any port down low on the carb body that has vacuum should be about the same amount, if one has more than the other that indicates that the true 'spark port' is partly open when it shouldn't be. That says the idle setting is too deep and exposing the transfer slot or holes too much. That alone could make the hesitation. Spark port should have no vacuum at all but then immediately has it as soon as throttle is moved open. If the throttle is idle set too high then it allows some vacuum bleed to the spark port and your lower vacuum point there. The hesitation comes from transfers feeding fuel to be too rich at idle, then instant too lean as throttle opened because all of the transfer flow has already been used up. Too rich at idle then leads to mixture screws set way too lean to cut back there and a double lean condition at off idle. Transition fuel off idle is from idle feed and transfer put together, if both are then lean, the problem.
Title: Re: 78 Bobcat wagon 2.3L distributor question
Post by: amc49 on June 27, 2014, 02:53:19 AM
Many, and by that I mean most, shops will not have a clue about that transfer slot thing, they just don't apply attention to detail like that. They won't have a clue how to fix it as well other than adjust the dile screw up or down, and no fix there. We did it because we worked on lots of drag cars and absolutely necessary that throttle roll on was 100% correct on ATX bracket cars.

Pull dist and check out the advance weights and pins for wear.......... ...
Title: Re: 78 Bobcat wagon 2.3L distributor question
Post by: amc49 on July 03, 2014, 10:18:35 AM
Odd indeed........ ....but then, the natural chaosian order of things in the physical world.

We think, therefore we are, oh ho, what a joke that one is............ .........