Looking for advice.....just failed emissions with an Opacity IN % of 63.4 and the standard is 40.0.
Anyone have any ideas? I would appreciate any suggestions.

No Mods, Chevy One Ton, 6.5, 4 X 4, 1996

Thanks

make sure the air filter is clean for starters. I know on gassers, dirty oil will effect emissions. Is it due for an oil change? Adding injector cleaner can't hurt. Is your turbo working? Check vacuum lines for leaks.

After you've checked and corrected the above, take it out on the highway and give it a good run. Keep it out of overdrive and clear the soot out of the system- if you pull a trailer, take it with you.
:grd:

I know it sounds silly...but my neighbor just failed also and he claimed it was because of his air filter. He had a dirty K&N filter in it with the lid off. Put a new Fram in it, put the lid back on and he passed with flying colors...It's probably not your problem but it may help.

that is a lot of smoke for 63%... something is out of tune... not enough boost maybe? plugged cat [if equipped]?

when i had my 6.5td, it passed emissions with no issues, but in ontario, it is a 5min idle test... not many places have the opacity meters yet

The hotter your engine/turbo when you test the better. It's possible your truck being stock doesn't help, the soot trap could be plugged. Test your vacuum pump at idle to see if it's making 25" Hg.

Pretty much what everyone else said but give a little more info on the truck. Anything done to the exhaust or intake?

How many miles on injectors and everything else? If over 100,000 miles on injectors news ones will make the biggest difference if everything else is reasonalably good. The rest of the advice will help but not make up for worn out injectors.

Do you run any additives? Lots of opinions there. Mine is good high volume clean truck stop diesel runs the best. Some additives increased smoke for me especially if mixed a little heavy. A light dose of lucas is ok for me once in a while.

Clean cheap paper filter (thinner the better to allow more air). You can go back to what ever you like after the test. Fresh oil change. Will help a little bit too.

I don't have to test my truck but my soot trap was pretty dirty when I did the new exhaust. I was very pleased and impressed with the improvement with the more open exhaust and better engine breathing.

The Lucas Upper Cylinder Lubricant is a perfect example of an additive that definitely won't help you on an Emissions test.

The whole idea is that the additive is a high combustion temp oil that won't burn when the fuel does, so the oil will stick to the cylinder walls and lubricate the piston. Whatever doesn't stick to the cylinder walls, pistons, valves and whatever else the additive claims to lubricate, goes into the exhaust.

Your truck appears to have seriously failed emissions by a large margin.

Does the truck smoke? what color and when?

Like Schiker says, we need much more info to help you.

I hooked up a vacuum to the pump, at idle it reads 17 hg's. It's supposed to be 24 ????
Truck is completely stocked.
Last year it passed with flying colors.
There's no black smoke when you're driving down the road, at all. There is a lot at idle though,when you press the gas.
Drives good otherwise.
There is a loud rattling sound when you shut it off....that just started a couple of days ago. Don't know if this would be related.

I'm looking for advice.

Thanks

Since you're only making 17 " Hg at idle from the pump, you can put the vac line directly from the pump to the turbo and bypass the wg solenoid. This should spool up the turbo and not set the ses light.

I connected the vacuum pre wg solenoid and got a reading of 23 hg's. After wg solenoid was 17.

Is that right? Is it still possible to go straight from the pump to turbo?

Thanks alot for all your help....I really appreciate it.

Thats about right, Vacuum pump is working fine. You will definitlely over boost if you hook it up direct.

I still say, get a new WG solenoid. Dealership sells them for ~$30.

Soot Trap? (muffler or Cat or something else?)
Can't believe all this to pass emissions!! :)

Soot trap=Cat Converter.

Are they just testing opacity, or how many other things too? A gutless cat opens up exhaust and makes that turbo zzinnnngg.

just opacity(63% reading standard 40%)

May want to just hollow out that kitty for starters. May not get you through emissions by itself, but makes engine happier.

I connected the vacuum pre wg solenoid and got a reading of 23 hg's. After wg solenoid was 17.

Is that right? Is it still possible to go straight from the pump to turbo?

Thanks alot for all your help....I really appreciate it.
What tex said.

if you have access to torches, you could clean out your soot trap... get a big rosebud tip and heat that soot trap's core up [need to drop the pipe section] to like 800° or so... that will burn out the soot pretty quiclky... once it is somewhat cleaner, reinstall it and it will be ready to catch soot again... [and once you pass the test, remove and install a test pipe and keep the soot trap for the next emissions test to swap back in]

Can't believe all this to pass emissions!! :)
LOL, All this??? Take it to a dealer and tell them it won't pass emissions, see what they tell you you need.