can't get my truck to start

[Toyz]

Someone needs to stick a stripe on this guy's slick-jitsu belt. You now know more about y block starters and old school points ignition that probably 99% of the people you will ever meet.

Except at Sllckstock!
Glad you didn't take the easy way out and have it towed to a shop! Good work, Dan!
Paul

[64 f100]

Glad you got it started, but you are still needing some more information, that was not suggested to you previously. First, diagnose the problem and this means going one thing at a time and checking things out. You should have a multi meter for the wiring, to check resistance, voltage, continuity, second you need more information about several things not mentioned by others. Fuel system problems mainly. How much fuel is in the tank? The fuel pickup tube in these tanks have been known to rot off, so that when fuel gets below a certain point fuel has not been coming out of the tank right. Rust is a major problem with these fuel systems, clogging fuel lines and filters. In addition, there are two rubber lines between the tank and the engine, one right below the cab and one from the frame to the engine. I suggest fuel filter from the frame to engine one regardless. Have you checked the condition of the tank for rust? How old is the fuel pump? I know you rebuilt the carb, but backfiring through it will blow the economizer valve, which causes flooding. That is the little valve on the bottom of the carb, some have weep holes some don't . If it has a weep hole, then it will be dribbling gas out if it is blown. If not, then you have to remove the cap and see if there is gas in it, if so then it is blown and must be replaced. I suggest you spend about 30$ and get a CD of the Ford manual for your truck. It's hard to do anything without knowledge. Some things are in this book some aren't, the latter is what we are for.
As to the electrical system, a mullti meter is your friend. I go nowhere without one. You should have 8 to 9 volts going to the ignition thru the pink wire coming from the ignition switch when turned on. The problems you run into by being a parts changer, and not diagnosing your problem first are you spend a lot of time and money buying things not needed. What happens then is you don't know for certain if you made it worse or changed out the part that was bad and made another mistake in the process. My first plan of action, if I can't figure it out right away and get it to run, is get it home where my tools are. The truck is obviously one that needs a complete checkout engine wise. Valves adjusted, compression test, etc. All these things are simple but take specific tools, but not all that expensive. Many small tests like compression can be done with the help of your wife or a friend. Valves on these older engines are very suspect as these needed adjusting every year or even every few months depending on miles ran. This is even more true today with our unfriendly crapgas. These engines did not have hardened seats in the heads. However they do become wear hardened from years of use. I had one 292 running on 5 cylinders because of burnt valves on three cylinders. Getting back to electronics though, the lead from the distributer to cold also needs to be checked for cracks etc.. The coil can be checked also and should be but this takes more equipment than you might have mainly an ociliscope. It's been years since I checked one and you can just find a known good one and substitute it and see if it changes how it runs. Your obviously unfamiliar with many things on the truck and are learning as you go. Stop and buy a manual and read then come back with more questions. The yblock engine is a venerable engine and a good one, but it is different from a modern one. If, I were anywhere close to you, I would be glad to help in person, but I'm not. There are several interesting site's for yblock info. John Mummerts yblock site is the first to come to mind. There are several others.
One last thing, advice to have a mechanic work on it could be a major mistake. Just because someone is a mechanic now days, does not mean he is one, nor that he would know about these engines and related problems. It most likely would be costly and you may or may not enjoy the experience. I would be very carefull in selecting a mechanic. and I would look for someone that has been one for 40 or 50 years with a god rep. Even then, it will most likely have been several years since they've had a yblock in the shop. What you are experiencing is not neccesarily yblock specific problems but having someone who used to work on these is a big plus in my book. You've actually come to the right place for good answeres, but it is hard to diagnose long distance. It takes time and a step by step approach.

Rich

[mac]

^i intend to get a ford manual for it. i'm an electrcian so the multimeter is my friend. i haven't really been throwing any parts at it, just did a basic tune up and uncovered some issues.

so now it starts right up and idles, but rough and is running way lean. infact it idles smoothest when fully choked, exhaust smells lean. i started with the idle mix screws out a turn and a half and went out a couple more half turns but it didn't cure the problem. so now i'm going to look for vacuum leaks, check float level again and possibly raise it a little.

[Toyz]

Sounds like vacuum leaks; I suspect you are above the idle circuit when running since it's lean. The idle air bleeds will have little to no effect in those circumstances.
As mentioned previously, might recheck the screen in the fuel inlet at the carb. The multi-meter is a pretty handy tool, and you CAN check a coil with one if the specs are known; same way with any electrical part. Personally, I suspect you have repaired the major electrical issues; again it sounds as if you are on the right track.
Paul

[mac]

what do you mean by "above the idle circut?" as in it's actually turning faster than idle and thus the screws have no effect?

what do you think about this: i have a browish-orange spark when pulling wires off the distributor, shouldn't it be blueish?

[Toyz]

Yes on both counts! It should be a bluish spark; condenser or coil are the likely culprits If you are pulling wires without a direct ground source, such as leaving them connected to the plug and just pulling them at the distributor, you may in fact see a weaker spark, since the spark still has to travel trough the resistor wires, then jump another gap at the plug. . As others have mentioned, a Pertronix solid state system to replace the points might prove to be a solid investment, especially if teamed with a "hotter" coil.
Yes, the butterflies are probably already opened beyond the idle circuit just to keep it running, thus the idle adjustments will probably have little effect, although actual engine speed may not reflect this.
Paul

[mac]

pertronix is definatley in my future. i was indeed pulling the the boot at the distributor and watching the arc. might have to go fire the y up on a sunday night and spray some fluid around the carb gaskets and vacuum lines. is there anywhere else i should spray to find a vacuum leak?

[Toyz]

Yep, especially in this case; pull the hose off the vacuum advance with the cap off, introduce a vacuum source ( of your choice), and watch for the plate on which the points are mounted to move. If it doesn't move the vacuum advance diaphragm is probably ruptured, (although the plate might just be frozen in place).
All areas of the intake manifold, especially at the heads, should be checked, as should the line going to the brake booster, if so equipped.
Be careful with that fluid in case of a stray spark, WD-40 might be slightly safer than other choices, although same potential.
Paul

[mac]

i will spray for leaks tomorrow. i've read some different things about vacuum advance. some people say it has no effect at idle, some say it does. if i pinched off the vac advance going to the distributor and the idle cleaned up, would that point to a leak at the diaphram? or would the engine not even idle if vac advance was plugged off?

[Toyz]

Vacuum advance is not in operation when the throttle plates are closed; if correctly plumbed. Because I suspect your throttle plates are slightly open, there MIGHT be a small amount of advance, although any diaphragm leak would not be substantial enough to cause your symptoms by itself. If the point plate does not move, however, and the centrifugal advance were also frozen, the throttle response would possibly match what you are seeing.
Paul

[mac]

welp. got it a little better tuned carb wise to where it runs without choke, still seems a little lean but i drove it around the block not finding any vacuum leaks with wd-40 so i might try starter fluid to get a tad more agressive. need to get a vacuum gauge, haven't figured a way to make artificial vacuum to test the distributor yet. when i pull #5's plug wire the engine doesn't run any different which indicates a miss but i have verified spark mulitple times. never missed before...

[64 f100]

Time for a compression check. As far as vacuum advance are concerned you need to make sure the line is connected in the right place and it will affect idle , as you are supposed to time the engine with vacuum advance disconnected. One thing not mentioned here , at least I have not seen it mentioned, is distributer shaft play. Take the cap off and get the points on a lobe then wiggle the shaft and see how much gap changes. Petronix is the way to go, and shaft wobble doesn't seem to affect running with it. Again I mention the rubber hoses coming from the tank. These can get extremely swollen and or soft where you are not getting enough fuel. Also modern fuel with corn chunks in it, eat old rubber diaphrams in fuel pumps and other parts. I cannot stress the number of times fuel system problems have come from the tank and lines. As to spark, if it will jump any real distance it should be good enough to make the engine run. Doesn't mean it will run well though. Coils will start to deteriorate the hotter those get. Break down under heat.

Rich

[Toyz]

Dan, might want to locate that factory manual soon!
Paul

[mac]

i know, i know! got a new plug in #5 and it cleaned the idle up a lot, i had read that just because the plug makes spark in the atmosphere doesn't mean it does in the chamber. so now it idles pretty good, not perfect. got the vacuum gauge hooked up and will do some tuning tomorrow. at least it's driveable.

thanks for all your help paul, anyone else would have (and did) loose patience with me

[Toyz]

Many of the chain auto parts will loan you a simple vacuum test pump. It's a pretty handy tool. Since I seldom use my 'scopes or distributor machine (not sure they'd even work anymore) , a coil tester is a handy tool also. You can adjust the test gap to find the maximum the system will cause a spark to jump. 1961 Ford manual 292 procedure suggests a 3/16" test gap.
You are correct as to a plug not firing under pressure/load even if it appeared and tested good while removed. A good plug makes a good test tool, though. Just open up the gap where the closest point is 3/16" ( around .090"), ground the plug body with a jumper, attach the wire and see if it will jump the gap.
Sounds as if you are getting close; other plugs may be intermittently weak from fouling, and may clear up with a few miles. If performance starts to drop off again, recheck that fuel inlet screen!
Paul

[mac]

will do. so how about this...my 50 year old y is pulling 19 pounds of vacuum warm idle. not bad. the needle is fluttering fast, not sure what that indicates. the charts i've seen on google images don't have a diagnosis for a decent vacuum/ fluttering needle reading.

[bobenhotep]

warped, sticking, or burnt valve will do that. It will flick down when the offending cylinder is on the intake stroke if it is a burnt valve. Since you have a y block you probably have solid lifters. There is no telling what the valve lash is set at. how far does it move on the flutter?

[mac]

it's too late to go out and fire it up but i think it was fluttering between 19 and 18.5, really fast. it would drop to about 15 when the throttle was blipped then return to 19-18.5. valve lash is for sure something i want to adjust soon.

[Toyz]

If the fluttering is limited to several in/hg or less, I would repeat my earlier suggestion; drive it; a small miss may be the source. As Bobenhotep stated, however, lash adjustment is a regular maintenance item on these vehicles. If the fluctuation were over several in/hg, it needs to be addressed, just to keep down the possibility that a balky or mis-adjusted valve may turn into a burnt valve.
Paul

[mac]

drove it for 40 minutes around town tonight, got some new gas, got it nice and warmed up and i felt like it ran really good. slight hesitation taking off from a stop. still around 19 in. vacuum. here's a question though: suddenly i can't get heat in the cab! didn't do anything with it since i've had it....how do the heat controls work? temp knob in=cool/ temp knob out=hot? what about the 'heat' knob?