Vacuum Advance Timing Question

Engine, ignition, fuel, cooling, exhaust

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Cal2121
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Vacuum Advance Timing Question

Postby Cal2121 » Fri Aug 18, 2017 6:23 pm

I just put a 390 (rebuilt) in my 68 F-250 CS. I have this distributor that I got from Summit (PerTronix Flame-Thrower Plug and Play Billet Distributors with Ignitor II® Module D133700). My father in law didn't think the vacuum advance was working, so I did some research on Fordification. Most of what I read said to pull the vacuum hose from the carb and suck to see if it created vacuum in the vacuum canister (i.e., my tongue should stick to the end of the tube after I suck on it). I did that and could keep sucking air, so I figured the vacuum canister was bad. I reviewed Summit's information (comments section) on my distributor and it said it used this canister (PerTronix Adjustable Vacuum Advance Canisters D909005). When I got the new vacuum canister, I tested it out before I put it on my distributor. I could suck air through it too without creating vacuum, so I did not put it on. I know I am missing something, but just not sure what. I don't want to spend a bunch of time fixing something that doesn't need to be fixed, or messing something up that worked. Any advice on what to check or do is greatly appreciated.

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Re: Vacuum Advance Timing Question

Postby sargentrs » Fri Aug 18, 2017 7:22 pm

Spend the $20 and get a vacuum tester at the parts store. You can use it later for bleeding brakes too. Pull your distributor cap off and hook the vacuum tester to the vacuum can. Pump it and see if the lever from the vac advance can operates. If it does, it's good. I don't think you can pull hard enough on it by mouth.
Randy
1970 F100 Sport Custom Limited LWB, 302cid, 3 on the tree. NO A/C, NO P/S, NO P/B. Currently in 1000 pcs while rebuilding. Project thread: viewtopic.php?f=22&t=59995 Plan: 351w, C4, LSD, pwr front disc, p/s, a/c, bucket seats, new interior and paint.
1964 Ford Fairlane 500. 289/Cruise-O-Matic, A/C, P/S.

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Re: Vacuum Advance Timing Question

Postby Cal2121 » Fri Aug 18, 2017 10:23 pm

Thank you. I will try that this weekend. Hopefully it's all working as it should be.

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Re: Vacuum Advance Timing Question

Postby Cal2121 » Tue Sep 05, 2017 11:11 am

So I bought a vacuum pump and hooked it to the canister. It just keeps pulling air with no movement and no vacuum held. If you look at the canister on the distributor and the replacement I bought, they both include little holes on the back side that lets air in. It just doesn't make sense to me. I sent an email to Petronix to see if they can help.

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Re: Vacuum Advance Timing Question

Postby 71Fe2O3 » Tue Sep 05, 2017 10:07 pm

I hope I don't sound too cranky, but I have seen many posts here from people with similar issues-some problem with the truck leads to electronic ignition, which leads to more problems.

You can set yourself up for trouble if, when your vehicle gives you trouble, you replace a bunch of parts-this gives you interesting multi-layered puzzles to solve but can be frustrating. It is likely better, and most definitely less frustrating to get to the bottom of the original problem methodically, get the vehicle running, and then add upgraded parts to a vehicle that is already running.

Besides, at the risk of sounding like an old curmudgeon, points ignitions, properly adjusted and maintained, are quite reliable, and problems are generally easy to troubleshoot.
Fred

1970 F100 4WD short bed, 360 engine, very rusty plow and yard truck

1971 F100 2WD long bed, 302 engine, on the road

1968 F100 2WD long bed, 360 engine, stripping for parts

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Re: Vacuum Advance Timing Question

Postby Cal2121 » Wed Sep 06, 2017 11:05 am

Fred,

Not cranky at all. I appreciate the response. The truck is running good. It's just that I'd like to get the vacuum advance working as well. From what I've read, it helps with power and efficiency.

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Re: Vacuum Advance Timing Question

Postby Cal2121 » Thu Sep 14, 2017 11:20 am

Just a quick follow up to what I learned. While it seems unlikely, both (the one that came on the distributor and the replacement I ordered from Summit) vacuum canisters were bad. I communicated with Petronix about my issue and the tech guy said I tested them right and they should hold vacuum. He was very helpful and personally tested a new vacuum canister and sent it to me free of charge.

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Re: Vacuum Advance Timing Question

Postby Lone Ranger » Fri Sep 22, 2017 9:06 pm

Wow that's pretty cool of petronix. If I go that route eventually I'll use them. Let us know if the new one works.
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Re: Vacuum Advance Timing Question

Postby bluef250 » Fri Sep 22, 2017 9:19 pm

Just because a part is new does not mean that the part is good! Quality control is often left to the buyer.

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Re: Vacuum Advance Timing Question

Postby farmallmta » Sat Sep 23, 2017 1:42 am

71Fe2O3 wrote:I hope I don't sound too cranky, but I have seen many posts here from people with similar issues-some problem with the truck leads to electronic ignition, which leads to more problems.

You can set yourself up for trouble if, when your vehicle gives you trouble, you replace a bunch of parts-this gives you interesting multi-layered puzzles to solve but can be frustrating. It is likely better, and most definitely less frustrating to get to the bottom of the original problem methodically, get the vehicle running, and then add upgraded parts to a vehicle that is already running.

Besides, at the risk of sounding like an old curmudgeon, points ignitions, properly adjusted and maintained, are quite reliable, and problems are generally easy to troubleshoot.


In general, I agree that "gee-whiz!" aftermarket parts often create more problems down the road than the one being solved today. This is a very good observation you're making... in general. But I'm afraid I have to disagree specifically with points and condenser ignition. Not because I don't like that type of spark control, but because all points and all condensers are now made in the C-word or the M-word. There is no quality control in either country for parts. My wife called me one day from a parking lot she'd managed to pull off the freeway into. Her '69 F250 was running fine and then started running terribly. I went there and quickly discovered the problem: condensers now have a short fastening tab spot tacked to the condenser body rather than wrapped all the way around like Autolite and AC Delco used to do back in the day. The workmanship and materials are so bad that the spot tacks (perhaps just a type of epoxy) broke lose and the condenser itself was literally FLOPPING AROUND inside the distributor. The only time the engine would fire was when the flopping caused it to contact the plate and ground properly. And it's a common problem now, or the condenser goes bad internally or the points burn up in under 100 miles.

So for that reason, I've had to eliminate points and condensers on my bumpsides and other old cars: bad parts, bad suppliers commonly on that particular category of parts. The times have changed, and not for the better. :cry:

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Re: Vacuum Advance Timing Question

Postby sargentrs » Sat Sep 23, 2017 5:24 am

That's what prompted me to swap to Duraspark in my Fairlane. 2 condensers went bad in a week. Didn't come loose like yours but just quit working with no warning. One day it was fine, next day wouldn't start with no spark. Of course that's not to say my ICM or distributor won't do the same thing since they were both probably imported from the same place.
Randy
1970 F100 Sport Custom Limited LWB, 302cid, 3 on the tree. NO A/C, NO P/S, NO P/B. Currently in 1000 pcs while rebuilding. Project thread: viewtopic.php?f=22&t=59995 Plan: 351w, C4, LSD, pwr front disc, p/s, a/c, bucket seats, new interior and paint.
1964 Ford Fairlane 500. 289/Cruise-O-Matic, A/C, P/S.

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Re: Vacuum Advance Timing Question

Postby 71Fe2O3 » Sat Sep 23, 2017 8:04 am

I see your point, farmallmta. Though I have been pretty fortunate with my trucks-I keep them with mechanical ignitions, and replaced all the old worn stuff with new parts that have held up well, I did have a vexing problem that led to a weak (yet new) condenser a few years ago. The truck was difficult to start-it acted as though it had a weak battery, though the battery was strong and all the ignition components were new. I fiddled and adjusted, did some research, scratched my head and wondered, and eventually came to think that it might be the condenser. I replaced it and, voila, the truck started right up with a resounding "whoosh" and a good, solid kick. Up to that point, I didn't think that condensers, being relatively simple devices, could go bad so quickly. The manufacturer, as bluef250 said, delegated quality control to the buyer.

Yet, as sargentrs noted, upgrading to a modern aftermarket ignition system comes with no guarantees, because its components may have come from the same places, or other places with similar manufacturing and quality control standards.

Though much blame is placed on the country of origin, the overseas manufacturers are as capable of building quality products as are our domestic companies. Chinese industries, for example, build all manner of products to satisfy the demands of their domestic customers. They have dozens of modern cities, hundreds of millions of people living modern lifestyles, and all the infrastructure that makes that possible. Those things wouldn't exist if their industries were incapable of building durable machines and parts. The blame, I believe, lies with the companies here who focus so relentlessly on cost-cutting, and, ultimately on us, the consumers who demand this and buy the results. The overseas manufacturers are able to take advantage of lax regulations and low labor costs, in addition to plain old corner-cutting, to make parts that meet minimum quality standards, can be sold at low prices, and generate healthy profits.
Fred

1970 F100 4WD short bed, 360 engine, very rusty plow and yard truck

1971 F100 2WD long bed, 302 engine, on the road

1968 F100 2WD long bed, 360 engine, stripping for parts

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Re: Vacuum Advance Timing Question

Postby colnago » Sat Sep 23, 2017 12:03 pm

Without belaboring the point, I agree with Fred. The foreign countries are CAPABLE of manufacturing quality components, but it's all about shaving pennies. The consumer is no longer the customer - the stockholder is. Welcome to the Corporate States of America. I'd love to say it's just for the old cars, where the customer base is small, but even new cars have problems. Nothing is built to last any more.

Back to the original topic, does the truck start/run? Even with no vacuum advance, it should run (and even drive, although it might not offer peak performance). Keep us posted. I know you said the cans won't hold vacuum, but you might find that the vacuum cans are all fine, but there's something in the distro that's jamming up the vacuum advance itself. Can you reach in and move it manually?

Joseph
"Sugar", my 1967 Ford F250 2WD Camper Special, 352FE, "T" Intake with 1405 Edelbrock, Duraspark II Ignition, C6 transmission, front disc brake conversion.

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Re: Vacuum Advance Timing Question

Postby Cal2121 » Fri Sep 29, 2017 12:17 pm

The truck ran decent without the vacuum advance but would hesitate ever so slightly when giving gas off of idle. I was hoping it was caused by the small vacuum leak from the bad canister. I received the new canister from Petronix and swapped it in (after testing to make sure it held vacuum). It immediately made a difference. No more hesitation and the truck seems to run better. The vacuum line was originally hooked up to ported vacuum, but after some reading on Fordification and other sites I decided to hook it up to manifold vacuum. Today was my first drive with that change. Runs good. Can't wait to drive it more and see if I need to adjust the vacuum advance if I get any pinging under load.

Thanks again guys. Really appreciate it.

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Re: Vacuum Advance Timing Question

Postby BobbyFord » Fri Sep 29, 2017 3:55 pm

Use a ported vacuum point, not manifold vacuum.


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