Hard to start

[6xchevy]

My 50 3100 has the original 216 which if I start her up a couple times a week does fine but if she sits for a couple of weeks takes forever to start up. A little gas or starter fluid in the carb does no good. Compression cold is 105-115 psi, points in good condition and gap is set to factory specs, spark plugs and coil has been replaced. The 6 volt battery actually spins the crank good. Any thoughts on why she is so hard to start? Thanks!

[iowaboynca]

fuel pump?

[OrrieG]

If starting spray or gas does not fire, then probably spark issue. Try jumper directly from battery to coil. If it fires then you know you have a short/loose wire in the starting or run circuit and can start chasing the wires to find it. If it does not, check a plug for spark, if none then could be the coil, or points/condenser issue. Might be just enough out of tune that simple adjustment will get it going again. Only adjust one thing at a time.

[mr48chev]

Are you setting the choke if it has a manual choke? It seems that every one of these old trucks has it's little quirks and you have to figure out how to get the choke set right, how many times to pump the gas pedal without flooding it (you do pump the gas pedal a few times ? As it isn't an FI engine) and what if any throttle opening it wants to start at.

[6xchevy]

Thanks for the suggestions, I will try the direct wire to coil and see what happens. Plugs, points and coil are new and gas is in the settlement bowl.

[Virginian]

Check inside distributor cap for moisture .

[6xchevy]

Tried the direct wire to the coil and starter fluid with no results. My dad used to say if they wont start, pull em or push em down a hill. Starting to sound like a good idea.

[Foot Stomper]

From over here it seems to me that you have a spark challenge.

You've confirmed adding fuel has no effect and that you've got new points, condenser etc.

Like someone mentioned earlier, change one thing at a time only. But if it started good before changing those parts, try putting them back in (assuming you still have them) one at a time.

I'm not an expert by any means... just a side line commentator ... but this is where I would concentrate my efforts... spark...

[6xchevy]

It only started good if I started it twice a week. Any time it sits for a couple of weeks, it is almost impossible to start. Wouldn't think moisture or point film would be an issue after such a short time. Does any body know of a HEI distributor that operates on 6 volts?

[6xchevy]

It only started good if I started it twice a week. After sitting a couple of weeks, it as always very hard to start. Anybody know of a HEI distributor that operates on 6 volts? Thanks.

[Virginian]

Is the truck stored inside or outside? If outside I would suspect a break down in insulation either coil/plug wires or distributor cap, letting moisture/humidity make a path to ground

[6xchevy]

Truck is stored inside but it wouldn't surprise me if moisture isn't the issue since it stays damp around here year round. Guess I will take the wife's hairdryer and dry inside the distributor cap, coil, etc.

[Highsider]

Originally Posted by 6xchevy

Truck is stored inside but it wouldn't surprise me if moisture isn't the issue since it stays damp around here year round. Guess I will take the wife's hairdryer and dry inside the distributor cap, coil, etc.

[Foot Stomper]

Originally Posted by Highsider

WD / Water Displacement. Great idea!

[OrrieG]

Is the battery holding charge during the two week period? If it is draining down do to a small short it might be an issue of not having enough to turn the starter and fire the coil. Was a big issue with 6V VW's. Also check your wiring and connections, a lot of small defects can add up to hard starting. WD is a short term fix, dielectric grease long term fix.

[dsraven]

I have found it is best to start with one system at a time. lets start with the fuel system.

after it has sat for a bit and usually won't start-before you try to start it-check to see if there is actually gas in the carb. remove the air filter and pump the throttle linkage by hand while looking down the throat of the carb. does the accelerator pump squirt fuel into the throat of the carb? is it a nice stream or a dribble? does it jet at the leading edge of the throttle plate when it opens? if not then the jet can be adjusted to do that. if no fuel sprays then start with that repair, whether it is an accelerator pump issue or a carb drain back issue or a needle and seat or float level issue. maybe the fuel is draining back from the carb so the float bowl is close to empty so the fuel pump has to start from scratch like you ran out of fuel. that would explain the long cranking time but eventual start. anyway, ensure the fuel system is all in top working order and the fuel is fresh. I have seen a few guys that have a glass fuel filter next to the carb, when the engine is cranked initially it is easy to see if the fuel is moving through the filter, that would indicate that the float bowl has drained back and the fuel pump is supplying fuel. you can always take the top off the carb for an actual check of the fuel level issue and, while it is off you get to see what is living in the bottom of the float bowl and can check the inlet needle and seat etc. some of these old fuel pumps can have valves that allow the fuel to drain back so that could be an issue if you find you are not getting enough fuel to start at first. the glass filter idea is also a good indicator that the fuel is clean and decent color with no extras, like water, in the system. also check to ensure the choke plate actually works through a complete range from fully open to fully closed.
if all is good there next check the spark. first make sure the distributor is all good and the rotor and contact points on the cap are clean and shiny. if they have been buffed up too many times it could be an air gap issue between the rotor tip and the cap contacts. also ensure the spring loaded contact on the rotor is good and the corresponding carbon contact on the cap is good. ensure the ignition coil is wired correctly so the spark travels from the coil wire to ground instead of vice versa. there is a pos + and neg - indicator usually cast into the top of the coil next to the wire connection studs. also check the tower area of the coil for a nice clean terminal for the coil wire to attach to. I have seen that tower green with corrosion down inside. this area is also known for carbon tracking so check with a strong light and a good set of magnifiers for that. run a white business card, or equivalent, through the points to see if they are dirty. check the gap, cam rubbing block, wire insulator on the housing, condenser connection etc. check to ensure you are getting full battery voltage here because a poor connection at the ignition switch or somewhere else in the system will mean that you can receive less than full battery voltage at the coil, so you will get less than a good hot spark-less in equals less out. buy or fab a spark checker and make sure you have a nice hot blue spark at a decent gap setting-a larger gap than the plugs have. first try the for spark at the source- the coil wire that goes to the distributor cap, then, if that is good, try the spark at the end of each plug wire so you know what you have there. if that is good then check the plugs next. if they have a carbon build up, like soot, then you possibly have a ground circuit through the soot so it will misfire. also check the gap of each plug and adjust to spec making sure the electrodes are nice and shiny.
if all is good there I would next recommend a valve adjustment check. as the valves wear they actually close the adjustment lash because they wear deeper into the head so the lash goes away instead of gets bigger like some would assume.
after that, if it is hard to start, try pulling a plug, after an attempt to start with no result, and see what is going on. if they are really wet then you may have a fuel issue that just got overlooked or you are giving it too many pumps before starting, or you have the choke pulled too much or if they are dry maybe it just needs a couple more pumps or more choke pulled etc. or-heaven forbid, you don't have enough compression to make it work. when the compression test was done was the engine warm, cold? did you do an oil test to see if the compression get better when wet? were the numbers within spec?
hopefully you get it figured out.

[6xchevy]

Thanks for all the advice, will give her a try again Thanksgiving day. Even with a weak spark, she should fire (but won't) when I use starter fluid.

[dsraven]

be careful with the starting fluid, you can do some damage if things don't go well.....

[Foot Stomper]

That's pretty telling.... You have an electrical challenge.
The starter fluid is not going to fix your problem. Plus it's very hard on an engine...very hard on it indeed.
Go have a rum and eat more turkey while you enjoy Thanksgiving with your family.