353 smokeing

graves logging · February 08, 2012, 08:35:10 PM

my old 353 was working fine .started to loose some power .now the white smoke gray smoke just rolls out when sitting idle and when u rev it up.has no power and sounds like it has a miss.the engine labours when u rev it up.what do u guys think injectors? pump?i did new fuel lines and filters and some deicers. >:(

bill m · February 08, 2012, 09:11:23 PM

Air filter maybe? Is there a lift pump before the filters? If yes then there should be a filter screen behind the fitting where the fuel line from the tank comes in.

graves logging · February 08, 2012, 09:27:04 PM

air filter is fine.the smoke smells like fuel

tlandrum · February 08, 2012, 09:49:17 PM

id be willing to bet its an injector.

Sprucegum · February 08, 2012, 09:57:35 PM

When I hear white smoke I always think antifreeze.

snowstorm · February 09, 2012, 05:56:50 AM

Quote from: graves logging on February 08, 2012, 08:35:10 PM
my old 353 was working fine .started to loose some power .now the white smoke gray smoke just rolls out when sitting idle and when u rev it up.has no power and sounds like it has a miss.the engine labours when u rev it up.what do u guys think injectors? pump?i did new fuel lines and filters and some deicers. >:(

white smoke = incomplete combustion. its not burning the fuel check the temp on the exhaust manifold is one colder than the others? often low compression. pull the air box covers look for broken things

lumberjack48 · February 09, 2012, 09:56:58 AM

Sounds like a cracked head !!

graves logging · February 09, 2012, 11:30:40 AM

thanks for the input just not sure where to start

sealark37 · February 09, 2012, 11:46:39 AM

Crack the fuel line to each injector just enough to make it leak. The injector that does not cause more missing when it is cracked is the bad one. If each injector reacts when cracked, do a compression check on each cylinder. You will find one low. Go from there. Regards, Clark

tapper2 · February 09, 2012, 01:45:54 PM

Check the oil to make sure it doesn't look like milkshake (oil and antifreeze mixed). If it's ok,...that's good. You may have a bad injector. Just pop the valve cover off, fire it up, and check like sealark37 explained. you may get oil all over when it's running, but that's typical for a detroit ;). An injector could be wet-stacking or just leaking. Not too complicated to replace, just setting the rack after can be tricky.
If oil is milky......brace yourself. Head to block o-ring seals are bad which also means the bearings have taken a bath.

lumberjack48 · February 09, 2012, 02:01:06 PM

Wipe in the exhaust pipe with a finger, if it taste sweet, head gasket, or cracked head.

Mark K · February 10, 2012, 07:59:45 PM

Could be a valve not closing completely. My 353 did it a few years back. started running on two cylinders. Checked the injectors, didn't make a difference. Pulled the cylinder head, had a valve with a week spring.

bushmechanic · February 11, 2012, 06:36:49 AM

The best thing to do is make sure if it is an injector or not.There is a couple of ways to check for this,one way is to remove the exhaust manifold and see if there is any wet in the exhaust ports-this will tell you if there is a problem and which cylinder is the troubled one.The other way is to remove the valve cover and with the engine running take a screwdriver and push down on the top of the injector-this stops the injector from working and you should immediately hear a difference in the engine rpm,if not then you probally have an injector trouble.Also do not open lines on a 353 because fuel with go down in the engine oil.Sounds to me like an overfueling injector anyway good luck.