VCCA Home Forums TECHNICAL - GENERAL Trucks and Vans My 1938 Chevy W1 won't idle

Hello everyone.

I finally got this thing running and man I forgot how cool it sounds...it has not been started in 14 years! My problem is this 216 won't idle at all. I have the original W1 Carter on it. I took it apart and stripped it and it's parts with carb cleaner and then I blew it out with compressed air. I put a carb kit in it and cranked it up. It does not run rough at all, but it won't run unless I choke it and then it runs at fairly high rpm briefly and then just dies if I open the choke. I can also keep it running if I continue to pump the throttle and thus engaging the accelerator pump. I am able to keep it running as long as I want at about 750 to 800 rpm if I keep the choke in the correct position and I got it up to normal temperature. A new low speed jet did not come with the rebuild kit, but I thought this might only cause it to idle rough...but still idle. Obviously it is not getting enough fuel, but what do you think is the problem? I'm thinking I must have missed something big during the rebuild.

Thanks

Charlie.....Sitting !4 Years?????? Holy Cow... you probably have a gas tank full of crap! Check the fuel pump, take off the glass bowl and the fine filter screen (I bet it full of sand looking flaked old gasoline) get the gas tank cleaned out and treated and blow out the gas line ...Now I would bet you have a load of crap in your rebuilt carb also....Good Luck ED1938

I already took out the gas tank and had it cleaned, replaced the fuel line and fuel pump before starting the engine. Sorry, I should have included that.

Recheck the float level and check for vacuum leaks. Sounds as if the low speed jet is plugged.

Switch #3 and #4 spark plug wires. Remove air cleaner. Start engine and hit the gas pedal hard a few times which will cause it to back-fire through the carburetor and blow out the low soeed jet.

Hello

I logged in under the incorrect address...I'm the guy with the W1 that won't idle.

I removed the carb again and it looks as if the low speed jet is not obstructed. Any other suggestions?

Thanks again

The only way to see if there is dirt in the low speed jet is to remove the jet. Once it is removed it CAN NOT be reused, must be replaced with a new one.
I would check for a vacuum leak and/or check the compression and nspect the spark plugs.

I removed the low speed jet when I rebuilt the carb and before starting the engine, so that ship has sailed. I read something that said these may be reused if something is used to return the jet to useful shape...for example the introduction of a tapered device such as an ice pick.

I have already checked compression and the engine has had a complete tune up as well. It actually runs quite smooth when it gets enough fuel.

Given that the low speed jet is now likely toast, wouldn't the engine still idle although rough?

Also, the carb has the idle adjustment screw on the base and has only 2 bowl cover screws. Is this not from 1938 and if so, will that be relevant to trying to solve this problem?

Thx

If your carb has only 2 bowl cover screws then it is the wrong carb for a 1938 its a earlier carb...The reason why they updated that W1 TO 3 bowl screws is that Carb was known to warp on the bowl cover, leak gas and suck in air. what you need is a Carter #391,#420 or #483 carb.
#391 is the 1938 carb but the #420 or #483 are better ....Good Luck...... ED

Thanks Ed and Chevgene.

My bowl cover is warped so I made some extra gasket material and it sealed it up.

I decided to take Chevgene's advice and check the compression...even though I had checked it myself before I got this engine running. Unfortunately one cylinder had 30# and the rest had between 105 and 110#...cold engine. Turns out the intake valve on that cylinder was too tight. I backed it off just a little and now it has 105#. I swear the thing seemed to run smooth at higher rpm, but my wife says I don't hear so well. Thanks Chevgene for suggesting the compression check...and while I had the valve cover off, I noticed that the nozzle for the oil line to the rocker shaft had come loose so I can't imagine there was much lubrication to the rocker arms or lifters (I was amazed there was no oil leaking, now I know why!).

Do you guys think that this could be the only cause for the lack of idle, or do you think my carb is a dud as well?

chevtrkmn..Yes your carb is a dud...BUT your compression is very...very good. The compression is good when it is 90lb per cylinder, anything above that is topping on the cake...congradulations...Good Luck....ED

You need to put the correct W1 carburetor on your 1938 instead of using an earlier 2 screw W1, which is an inferior carburetor.