AZDirtBiker17

i own a 1985 chevy k-10 silverado with a 400ci engine and it wont stay idling... i looked closer and two of the cylinders are not getting any combustion.. after babying it for a minute or two, two of the headers (exhaust connected to the engine block please correct me if im wrong) well.. two of them were still cold, i put the sparkplugs from the bad cylinders into other ones that WERE firing off...and they kept firing, so the plugs arent the problem... please help! i cant stand having my baby not working and cant afford to take it to the shop. other things... at high RPMs it seems to run better with lots of gas.. but it refuses to stay running on idle due to only firing 6 cyl.s please be a cheap fix.... oh! the problem came up when my dad was driving it... we were on route 66 going about 70MPh and instead of shifting into OverDrive he shifted from Drive(main) down into Drive(2) and the RPMs screamed like overrevving it...and it jolted and he shifted back up, and into overdrive... if that helps any, it was in 2wd, the brakes werent on, and we havent moved it in a few months, weve recharged the battery and cheakced on any other cylinders misfiring... i only state all this because this isnt the first forum ive been on please help! im this post is in the wrong spot, please let me know.

Allan In NE

So,

This problem started immediately after the hiway incident and has been missing ever since?

The first thing I would do is give this engine a compression test.

Allan

grumpychevy

Your not getting any spark, check to make sure your plug wires are not burnt through. You can see this at night with engine running- look for arching under the hood. It may also be your distibutor. It is not good to run this engine any longer than for simple check of things as without spark to burn the fuel inside the cylinders the fuel could wash the oil off of the cylinder walls meaning an engine rebuild.

AZDirtBiker17

yes, i am getting spark, i took the two non-firing cylinder's spark plugs and put them in some of the other firing cylinders, and they still got full combustion, so its not sparkplugs... im just not getting compression on two of the cylinders... after running the truck, two of the headers are still cold! anything here help out? and yes, the incident happened immediately after the highway incident.

grumpychevy

Read it again, I said nothing about the spark plugs. You do not have spark in those two cylinders. I would start at the distributor. Do you have points or an HEI? Do you have a carburetor or fuel injection? FYI you have to have spark to have combustion. No spark= No combustion.

AZDirtBiker17

@grumpychevy sorry my apologies, i will check that ASAP! its got a carb on top, and im not sure what HEI/points is.