cold start missfire

[GREASEMONKEY72]

back story is i pressure washed my engine, forgot to flip the lid on my aircleaner so the filter got wet, went to start it when i was done and it wouldnt and it continued not to for a couple hours, between waiting and even spraying wd40 in the cap it finially started and ran fine after that

the next morning when i started it up it idled with a real bad miss and would not go away, cleaned the plugs and it was ok for a few days then it did it again so i just put new plugs in and it was fine again for a little while, now from time to time it will idle rough on a cold start but then be fine after warming up and drives around fine


my first thought was i hadnt gotten all the moisture out of the engine being winter months but yet even after driving it on the freeway and higher speeds it still did it


its better now than it was before but it will still sputter on start up times

[Stocker]

Maybe sucked some water into the carb? I've had 'em start hard and sputter for several minutes washing under the hood, but nothing like you are describing. Engine heat should have dried everything out before now.

Dunno if it's true, but I've heard that spraying WD-40 inside a distributor cap can cause an explosion....

[Hottrucks]

wd 40 is not what it use to be but its NON flamable now

I would spray the carb and lub it up you may have a sticking choke/linkage also check for loose, cracked or broken vacum lines

[GREASEMONKEY72]

i might not be able to check untill this weekend but ill keep that in mind

ive been meaning to give a good lookin at but havent had time and thought i would post here anyway just incase i didnt think of something

[Hottrucks]

a can of carb cleaner while its running will be a good idea then a little lub on the inkage will go a long way

[69GMCLonghorn]

Continue the process of elimination. If you cleaned, then replaced the plugs and it helped, you can deduce that the problem is pretty much spark related. Put a new dist cap and rotor on it and see what that does. Then check the carb. Honestly, I doubt it's the carb, though. If it was, it would usually clear out after a few minutes of running like crap, then it would be ok.

[GREASEMONKEY72]

im thinkin of replacing the cap and rotor, they have been on since i got the truck the truck almost 4 years ago

[coloradosean2009]

I think that you had arcing on the plug wires from the water. Burned a weak spot in the insulation, intermittant arcing again. Or the connector to the HEI got wet ?

Look for signs of burning on plug wires.

[72lb4x4]

To continue with Sean's idea, try starting it cold after dark and look under the hood for arcing...

[spdrcr405]

what carb is on it?? Holley? if so u mite check the "power valve". just an idea

[bhoeger70]

Very good chance that it carbon arching on or in the cap, pull it off and have a look it will look like someone drew on it with a pencil.

[GREASEMONKEY72]

orignal points system

quadrajet carb

im going to try and tinker on it tonight when i get home


been drivin a company truck and getting home late for the past month and a half

thanks for the input guys

[67ss&99ss]

Check the vacuum hoses. On my nova, I had it backfire once though the carb, and it blew one of the vacuum caps off of one of the ports on the 2 barrel. It ran terribly. Replaced the cap and ran great. Always check the simple stuff first.

[GREASEMONKEY72]

im hoping i can get out there this weekend in the daylight

[fastom]

Steven, if you need some help let me know. We can get together Saturday if needed.

[GREASEMONKEY72]

thanks tom

[GREASEMONKEY72]

kinda forgot about my own thread, lol


i drove it the other night after sittin for about 2 weeks and it fired up and ran fine with no stumbles and i havent done anything to it so now i dont know untill i drive it again

[cdowns]

have you cleaned and gapped the points like required for routine maintenence?

[Stocker]

Glad it's running OK now. I bet next time you'll remember to flip the air cleaner and put a baggie over the distributor!