Posted by Alan Bowes on October 10, 1997 at 23:59:18:
In Reply to: WON'T START EASY! posted by JIM C. on October 10, 1997 at 17:22:17:
: I have a '41 Dodge WC series with the standard flathead engine- This truck WILL NOT start without using starting fluid first- I have tried a tune-up, new carb., new fuel pump, hotter plugs, timing, new distrib., etc., etc.- Does anyone have any ideas? Are the valves suspect here? Keep in mind this is "one tired old truck" so a major overhaul is due soon, but I would like to keep it running through the winter. I really appreciate everyones help on my brake and 12 v. conversion questions.
Your hunch about compression is certainly reasonable. If you have leaky valves and/or rings, the slower the engine is turning, the greater the percentage of compression loss due to these leaks. Therefore their effect would be most noticeable at cranking speed. Have you done a compression test? Engines with weak compression are typically harder to start unless you've got a starter that can really spin the crank quickly so that it can still compress the fuel-air mixture sufficiently. Even if you don't have good compression, that doesn't mean that you can rule out other possible causes, of course.
If rings are the culprit, you can boost compression somewhat with one of those thick oil additives, though I'd never use them in a "good" engine. If valves are the problem, there's not a lot you can do, even temporarily, other than a valve job. While you're doing a valve job, you might want to have harder, more burn-resistant valve seat inserts installed that better tolerate unleaded fuel.
A weak spark (from several possible causes) is another possibility.
By the way, is it hard to start with the engine both cold and hot? Choke make any difference?
Alan