Engines quits after 15 minutes - need your help

I recently replaced my alternator and performed all the checks required for battery and alternator while off and while loaded and did the draw down tests and everything passed. Today when coming off the highway after driving for 30 minutes at 55 the van (1967 170) quit and wouldn't start. After towing it home and verifying there was plenty of gas and a working fuel pump i tore the carb down and cleaned all passages. This all took about 3 hours including the tow time home. I started the van and it idled and went into gear without bucking or stalling so i thought i had it licked. I went 15 blocks for a total of a 10 minute drive and it died again. A slight bucking and a 'blub blub' and that was it. After many tries to restart i gave up and just sat there waiting for another tow. After about 20 minutes with the engine bay open it started but was rough on idle and would only idle with me feathering the gas and would only start while giving it gas. When going into gear the van jerked and rumbled and died. I waiting for 30 minutes next and it got a little better on idle and starting with less gas and went into gear for a few moment smoothly then bucked, shuttered and died again. After waiting another 30 then getting hooked up won the tow, talking to interested people and driving home, the van started and was able to make it up the alley and into the garage without issue (making me look like a liar). I know this is long winded but i want to be detailed. I am thinking coil at this point (?). The distributor looks brand new but i have to wait for the PO's response on that. Any suggestions are welcome. Thank you

When you say it died after 30 minutes, I am assuming when you tried to restart it would crank, but not fire off. You said you recently did some charging system work, so let’s start with that first. Was this the first long drive you made since the alternator replacement? If yes, do you have a voltmeter in your cluster, or do you have a hand-held unit to see what kind of voltage is being put out? If the regulator is not doing its job and you are putting out more than 13.5 volts at 55 mph, it can overheat your coil (among other things). The coil is oil filled and will generally get very hot if this condition exists. When it cools it might be fine for a little while, but will fail again in short order. A replacement coil will only cure the problem if you correct the overcharging problem first. Same thing goes for the distributor module if you have an electronic ignition installed – high voltage will fry it. If no problem is found there, and you verify you have a good strong spark when this happens, only air and fuel are left. By “feathering” the throttle you are keeping it running on the cruising circuit, bypassing the idle circuit. If you have to hold the throttle open to keep it running, you can have anything from a collapsing fuel hose, weak fuel pump, vacuum leak (too much air) plugged filter, contaminated gas, a speck of dirt in an idle circuit passage, restricted exhaust, vapor lock or a hundred other things!. The only thing I can add with great certainty is if the problem occurred after repairs were made, the problem is almost always related to what was done. There is coincidence in this world; it just rarely applies to auto repair.

Did you buy the Terry Abbot's Wambulance?? That's a pretty cool Econoline. I know it was up for sale but hadn't heard if it sold.

Sounds like you have a fuel problem to me. When it stalls look and see if any gas shoots out the accelerator pump nozzel. If it's not a steady stream then it's fuel. Either your fuel is overheating in the line due to the line touching the hot engine. IE. Water hoses, intake, exhaust, Isolate the line and insulate it if need be. It could also be caused by a dirty sock in the fuel tank. Rust and trash in the tank could clog the sock on the pickup tube attached top the fuel sending unit. After sitting for a few minutes without any suction against it the debris will fall away from the sock allowing it to pump fuel again untill it gets blocked. A vicious cycle. If it's a dirty tank I would drop the tank, have it cleaned and sealed or just replace it all together. It's hard to fight a rusty tank. That truck has sat a lot of it's life. I'd say it is more than likely a rusty tank issue. It's only got around 5k or 6k miles right?

HTH.
Duane in Tennessee.

Yes, the van I am talking about is Terry's van. Thank you for all of the replys. The engine does crank after it quits but it wont fire. It can crank over and over and over. I took the van for its first long drive yesterday after replacing the alternator and thats when it failed on me after about 15/20 miles on the highway at 55. I have no voltmeter in the dash and have to use a handheld unit to tell what volts i get at 55mph. As the van cannot even make it 15 blocks without quitting now, the test at 55 isn't going to happen. I see fuel in the line right to the carb as it is clear so i beleive it is getting fuel as it needs it. I do however agree that the tank needs to be cleaned or replaced. If the van is left for a few hours it will idle on its own without intervention from me, it is only after the failure that I need to feather the gas to keep it running and only roughly. The accelerator pump does work. I hope it has something to do with the new alternator I installed. I didn't replace the regulator. The batter was at about 12.57 without power and about 15.1 or 15.3 while running with no load. The draw down tests were in the ranges they were supposed to be (.0/.2). Under load I think the batery was measuring 13.5 or so, maybe slightly higher. Thank you

Basics-like doni is saying=You Must verify= when it is dead=Is there spark???????? Fuel???????? See if you have either one -fuel inside carb throat/accelerator pump is working?? Then depending of what distributor you have =?? electronic or points type-verify when you crank there is spark=look & verify.What distributor do you have?

i will have to let it die again to verify the spark issue. I guarantee when i go to start it after work it will start and idle and drop into drive and go fine untl it heats up. I see fuel squirting from the pump after it dies when i have the air filter off. I see fuel in the clear line going to the carb after it dies and in the fuel filter before the fuel pump. I have the points dist and will look at that for spark next time it dies. It looks like a stock light colored grey distributor which is VERY clean inside and out but the coil looks like the original which is mounted right on the engine block. The problem with fixing this issue is i need to drive it till it dies in order to check the spark and other items and getting stranded just to check some of these things is an issue in itself. Thank you for the replys.

if you start it and let it idle in the driveway for 20 mins does it die?

I'm thinking something ignition - sounds like you have charge and fuel issues reasonably ruled out.

Mike - thats is EXACTLY the next course of action - i iwll start it then let it idle and see what happens. Yesterday was the first isse i had and after all the waiting and towing and carb rebuilding,etc. i didnt have it in me to sit in the van or be nearit anymore to test something simple liek that at 11:30 at night. I have a suspicion itis electrical/ignition and hat after 20 minutes it will begint o idle rough, shudder and just die and tehnnot retstart but i will try and see what happens.

what ignition =distributor do you have installed=HEI??

I honestly dont know. How could i get that information? I would think it cant be HEI as there is a coil bolted on the block, a small condenser in the distributor along with teh points ignition.

She is making me work as her new owner. I think she demands I earn her respect. The thing that irks me the most is all of the greasy finger prints on the white paint. I replaced the coil this evening and it started and idled and drove fine and i got it up to operating temperature around the neighborhood. At one of the stop lights it started bucking and i just took the right to keep the van rolling so it wouldnt stall. I stopped and raised the idle a bit higher than normal and she stayed idling. I got to my alleyway 15 blocks away and again just like in the original breakdown on thursday afternoon, it started to quit after i let off the gas and let the van at coasting speed get over the very slight hump into the alley. I was disappointed as i thought the coil was the solution and out of frustration i stabbed at the gas pedal as it was dying and blubbing and shuttering to a stop and right at that instant the tires hooked up with the gravel and peeled out. I didnt stomp on the gas or jam it to the floor, i just stabbed it with the tip of my foot. BANG! She takes off and i stop in front of my garage and she is just purring. Now at take off from stop lights its all energy and no hesitation or flat spots in acceleration. She actually feels like she has more power and pep that when i first drove it. I take her back out and purposely stay in drive and let it idle long at stop signs and behind closed businesses and she doesnt miss a beat. I stopped for water and shut her off and came back out and she started right up and was faultless. I hope writing this doesnt jinx things. I just dont understand what the issue was. Gas was definitely getting to the carb and the accelerator pump was working and spraying gas. I took the whole carb off the block and stripped it down and soaked the jets and cleaned the passages with pressure from the carb cleaner nozzle and wire pieces and put it all back together thursday and it didnt change anything. The only variables are new coil and me stabbing at the gas pedal.

do yourself a real favor- get all the tuneup parts - points, condenser, cap rotor , wires & plugs - do it all & set wit dwell meter also! reset check crank timing also- likely all will be fine

I will be switching over to the ignitor ignition system on macsautoparts.com along with the new plugs, rotor and coil that go with it. Once that happens i dont believe i need a dwell meter. I assume i have to reset the timing when i do get the ignitor ignition correct?

some blockage in the exhaust path which you cleaned out through hard acceleration?

i really wish i knew. i honestly wouldnt say i accelerated hard though. It was just a very quick stab at the throttle. It was quick but only went down about half way in its travel. I wish i could provide more info in case anyone has a similar issue in the future. I will see how it behaves tomorrow after it rests for the night. I will take it on a highway run and see how it does.

fuel filter seems plugged

Drew Peacock wrote:I will be switching over to the ignitor ignition system on macsautoparts.com along with the new plugs, rotor and coil that go with it. Once that happens i dont believe i need a dwell meter. I assume i have to reset the timing when i do get the ignitor ignition correct?

it wouldnt hurt to check your timing but every ignitor ive put in didnt change the timing at all. i just installed it and off i went. dont be surprised if the ignitor module sits on the other side of the distributor opposite of where the points used to be. I remember the first one i installed. I kept saying to myself..this isnt gonna work..this isnt gonna work..cranked it up and vrommmmmm. they are a good investment! I was going to recommend you upgrade to one...and no, you wont need a dwell meter.

Keep on it...you ll earn her respect. then you can live happily ever after.