[mark496]

Here's a problem that has me stumped. The truck is a '82 D150 with a stock 318 2bbl Holley. Now here is what it is doin. Cold starting is not problem, hit the gas pedal two times and she fires right off. Now drive untill its warmed up good shut it down and wait for 15 to 20 minutes and try to start again and all it want to do is crank and not fire. Sometimes it acts like its flooded and other times it acts like there is not gas. Yesterday it did this and I hit the gas a couple of times and it fired off, but there are times when you do the same thing and its flooded. Here is what I've done so far. The carb has been rebuilt twice carefully, even tried a second carb and still the same problem. New plugs, wires, cap, rotor, and control module. The engine has 190,000 miles on it so I know that the rings and valves are weak, but I don't think this is the whole problem. Any ideas would help

Mark

 

[mark496]

Forgot to mention, the battery is good the thing will crank for ever with out showing any signs of slowing down. I read another post where someone changed to a high torque starter that spins the engine faster. Could it be a simple as the engine is turning to slow with the stock starter??

Mark

 

[KCIN5]

Is your choke working and hooked up? Are you sure the float was adjusted right when your rebuilt the carb? Did you remember to change the needle and seat when you rebuilt the carb? Did you get all your vacuum lines hooked back up right?

 

[mark496]

Yep choke works like it should, float set per spec sheet, new needle and seat. The fuel pump is about 3 months old along with new fuel filter. The last time I rebuilt the carb I pulled the top off before removing from the engine to check fuel level and it was were it should have been. The egr valve vacuum line has been blocked off for a long time, but it does not have a block off plate under it. All of the vacuum lines have been replaced and in the correct places. I've hit about every area that I can think of so far except the egr valve and the check valve on the brake booster ( which is only 4 months old). So if you guys can think of any other areas let me know.

Mark

 

[mrpeal]

hey mark, next time it is just cranking and not starting check to see if the accel pump is delivering fuel when you hti the throttle, if so then look to ignition problems. if no fuel though look at the possibility of vapor lock, when the engine cools it generates excess heat and maybe on of the fuel lines is contacting the block or exhaust somewhere, if that is the case it will evaporate the fuel and then the pump cant get fuel in as it is vapor only, making it hard to start, hope this helps ya some

jamie

 

[mark496]

Thanks Jamie, I don't know why but I never thought of a vapor lock. My old Road Runner used to do that a lot. I'll check it out a see if that takes care of the problem

Mark

 

[mrpeal]

see what turns out, if not we can all give ya some other ideas. see ya

jamie

 

[mark496]

Well, it's been in the 30 to 40 degree range here lately but your right it is usually warm most of the time. As for setting for a period of time sometimes it will start right up after setting 30 minutes sometimes not. I did notice something last time I removed the carb, I had it running, shut it down and cracked the fuel line loose from the carb and it didn't spray like they usually do from pressure. This carb also has an electric solenoid that shuts off the bowl vent when the engine is shut off, if this was not working it should only effect things while the truck is running right? I'm going to check today and see if the fuel line is up against the block or maybe a heater hose and causing a vapour lock like was suggested above. I'll let you know

Mark

 

[mrpeal]

i think your talking bout the bowl vent solonoid, they do only open and close when the key is on but they can fail in the closed position although i doubt it is causing your problem as it would create problems running down the road as well. if it failed open you would never know it and if closed it would make it tough to get fuel into the bowl. good luck

jamie

 

[mark496]

Found it, the only thing I didn't change was the coil. I guess it was getting hot and breaking down. Now that I think about it, this is the original coil. Any way it seems to be working okay now. Went the long way around to find the problem, but at least the old truck got a good tuneup. Thanks for the suggestions everyone.

Mark