rowdy235

Hi all,

Been searching around trying to find some insight on my issue. I see lots of people having the problem, but very few seem to fix it (well, at least few post back what the problem was )

For anybody who has been following this is my 78 Flatbed which was formerly a camper. A friend and I pulled it out of the bushes (literally) about a year ago and I've been tinkering with it since.

As it stands I've got it running pretty good. When cold can pump twice and fires right up, high idles good, and kicks down to a good warm idle around 800rpm. The trouble comes when going to restart when warm. If you just turn the key (no pedal) it will crank 5-6 times but then finally start. If you try giving it "a little gas" it will usually just crank and crank and crank. The only solution I've found is to pump it once (like its cold) and it will usually fire right up. But I am worried that continually doing that will flood it. Plus, I know its not normal and would like to get it working a little better.

A couple points-
I've desmogged the entire system less the EGR/PCV valve
I recently discovered my vac advance was not working so I fixed
The truck idles and runs well, has plenty of power, etc.
Fuel system is clean, new filter, etc.
Recent ignition tune up and air filter

My next steps are going to be to re-time and inspect the idle mixture. I've felt for a while it may be running lean at idle.

Any comments/suggestions welcome

L5wolvesf

How old are the starter and battery?

rowdy235

Battery unknown vintage but good power. New starter.

Guess I should have been more clear, engine cranks over good just has trouble starting.

farrier

On my '83 when it's hot and I have to restart, I hold pedal to floor.
Fires right up.
If I don't do that, it crankes a bit then fires.
When cold, I have to hit the pedal a few times then let off to start.
All stock equipment.
Maybe different for '78.

rowdy235

That is what I would expect, and how both my 82 and 77 behaved.

Trouble is, if I hold the pedal down when warm on this one it will not start, in fact it makes it harder. Seems to me like its not getting fuel at first when cranking. Maybe float level needs adjusted?

13Swords

Hiya Rowdy, long time no gibber. Did you keep your stock carb after the desmog or go with the Weber? I can't remember, gettin old ya know. Don't know too much about the Weber but have heard that too high a float level could do it, or fuel pressure is too high. Seem to remember it should be 2.5 to 3 psi. The stock electric pump in the tank is rated for 5 psi minimum, 8 psi max so with that pump the Weber has to have a fuel pressure regulator.

If you kept the stock carb I just may have an answer for you. I've also had hard hot start issue ever since I did my desmog; when hot (5 minutes to an hour after shut down) it's cranks & cranks with no signs of even trying to start. After the 3rd to 5th try it will either act like it's starting then throw a bunch o white smoke out from under the hood, then start on the next try, OR, sorta start, bumble & stumble (crap idle) & throw lots of white smoke out the tailpipe. After 20 seconds of this it idles fine like nothing happened (fickle wench that she's being). Runs perfectly fine afterwards so nope, don't say it, NOT a head gasket. In the middle of a possible fix here so let me know if you kept the stock carb; it could apply to your situation.

13Swords

I put my EVAP canister (charcoal canister) back in last week. Decided that boiling gas vapors were flooding out the carb on heat soak after shutdown (vapor lock). Hooked up the lines from the carb bowl vent & tank vent line & plumbed the vac purge line into ported vac. This way it only draws vapor from the canister above idle, & doesn't mess with my idle mixture. This helped the hot hard start problem about 40%, but problem not solved. Poking around the carb I realized that the throttle positioner adjustment screw was backed out all the way, so it was doing nothing. It keeps the throttle plates from slamming closed the last 5% of travel, preventing exhaust backfire from an over-rich condition. Got it adjusted so there is a 2 second lapse from rev to idle; from 2000 RPM to idle speed. Got rid of most of the tailpipe popping & improved idle quality a bunch; still does it lightly on decel in gear. Hot hard start problem still there.

Then yesterday I decided to test my ignition coil. It's almost cooked, resistance readings wayyyy above spec so coil wasn't getting enough juice. Once it cools off for 20 or 25 minutes it starts like nothing ever happened. So new & better quality coil on the way. Stupid chi-nee crap coil only lasted 2 years. Maybe you should test your coil too? If my new coil solves the hot hard start problem I will let you know.

13Swords

New ignition coil solved the problem on mine. Now starts hot every time in half a second or less. Went with Standard Motor Parts/Intermotor Part # UF2, much better quality than the Chinese cheapie I had.

Weird thing tho - I had to order it from Rock Auto to get it. Local parts houses don't seem to stock the good stuff any more, only the crap quality stuff. If you want better quality they say it's "special order." Feh. Guess they want you coming back every 6 to 12 months & spending more $. Their prices are also double Rock Auto's prices, AND they want you to pay for shipping, to their store, so you can pick it up with your non-running vehicle. Makes no sense at all.