My Sy wont pass emissions testing
- Thread starter jimhrabe
- Start date
Divergent Lightning
woah
Re: My Sy wont pass emissions testing
have you turned down your fuel pressure when you go to get it tested?
have you turned down your fuel pressure when you go to get it tested?
Divergent Lightning
woah
Re: My Sy wont pass emissions testing
Do you know how to check your timing?
i would get a adjustable fuel pressure regulator. It is a good thing to have for you truck.
Do you know how to check your timing?
i would get a adjustable fuel pressure regulator. It is a good thing to have for you truck.
0966Sy
Code what?
Re: My Sy wont pass emissions testing
KEEP YOUR FUEL PRESSURE AT STOCK AND IT WILL PASS!!!! Considering everything else is good. Put the timing back to stock (0) with the tan wire dissconected and then reconnect when done. Make sure you have no vacuum leaks and the truck idles with 20-18hg. New plugs, fuel filter and an oil change to be anal about it.
Lowering the fuel pressure from stock 38-42psi base with vacuum line off the regulator will only cause more heat in the combustion process causing extreme combustion temps over 2500 deg F spitting out NOX like crazzy. If anything raising it a bit would help if you have high NOX on the first test, cooling the combustion temps but adding to the carbon monoxide level. Under these conditions it will pass....
Closed loop
good 02 sensor
proper engine temperature
no vacuum leaks
effective cat convertor
fuel pressure at 38-42psi base, preferably 42psi
no severe engine knock
good gas 91-93 octane
timing set at zero
Good plugs and ignition componets, wire, cap and rotor, ext
new fuel filter with less then 25-30k use
reasonably new oil
PCV valves flowing good, with new oil wont matter
clean air filter
EGR valve not stuck open, you'll know if it is becuase it will want to die at idle.
do these and you'll be just fine with the OBD1 3 speed idle test
KEEP YOUR FUEL PRESSURE AT STOCK AND IT WILL PASS!!!! Considering everything else is good. Put the timing back to stock (0) with the tan wire dissconected and then reconnect when done. Make sure you have no vacuum leaks and the truck idles with 20-18hg. New plugs, fuel filter and an oil change to be anal about it.
Lowering the fuel pressure from stock 38-42psi base with vacuum line off the regulator will only cause more heat in the combustion process causing extreme combustion temps over 2500 deg F spitting out NOX like crazzy. If anything raising it a bit would help if you have high NOX on the first test, cooling the combustion temps but adding to the carbon monoxide level. Under these conditions it will pass....
Closed loop
good 02 sensor
proper engine temperature
no vacuum leaks
effective cat convertor
fuel pressure at 38-42psi base, preferably 42psi
no severe engine knock
good gas 91-93 octane
timing set at zero
Good plugs and ignition componets, wire, cap and rotor, ext
new fuel filter with less then 25-30k use
reasonably new oil
PCV valves flowing good, with new oil wont matter
clean air filter
EGR valve not stuck open, you'll know if it is becuase it will want to die at idle.
do these and you'll be just fine with the OBD1 3 speed idle test
0966Sy
Code what?
Re: My Sy wont pass emissions testing
Regardless what people tell you..... you want a stoich burn 14:7:1 and it will pass. Lowering or raising FP from stock will increase your chance's of not passing with a stock motor as far as cubic inch's go and higher compression ratio's. Your ECM is trying to keep a 14:7:1 air to fuel ratio, engine vaccum, FP, clean air, filter and ignition and timing have the biggest effects.
Regardless what people tell you..... you want a stoich burn 14:7:1 and it will pass. Lowering or raising FP from stock will increase your chance's of not passing with a stock motor as far as cubic inch's go and higher compression ratio's. Your ECM is trying to keep a 14:7:1 air to fuel ratio, engine vaccum, FP, clean air, filter and ignition and timing have the biggest effects.
jimhrabe
Donating Member
Re: My Sy wont pass emissions testing
they said on the test I was high on the HC side.This thing is really pissing me off, I get it to pass one year and the next it fails. any help would be greatly appreciated.I'd be willing to pay one of ya guys if you're local to get this thing tuned in for me this has been going on for the past 5 years,and its really driving me up a wall.
they said on the test I was high on the HC side.This thing is really pissing me off, I get it to pass one year and the next it fails. any help would be greatly appreciated.I'd be willing to pay one of ya guys if you're local to get this thing tuned in for me this has been going on for the past 5 years,and its really driving me up a wall.
0966Sy
Code what?
Re: My Sy wont pass emissions testing
Hydrocarbons are from incomplete combustion..... possible causes....
Poor secondary ignition-bad plug wires,plugs,cap,rotor,weak ignition coil,shorted ignition coil,OVER ADVANCED TIMING.
Low Compression-worn rings,burnt valves,blown head gasket
Sticking EGR valve
If your HC's are high your C02 will be lower than normal, o2's will be higher than normal, and CO could be high low or normal.
Sounds to me like it's your timing considering the thing's you have changed and you mentioned you had a shop "adjust your timing last" Hope this helps
Hydrocarbons are from incomplete combustion..... possible causes....
Poor secondary ignition-bad plug wires,plugs,cap,rotor,weak ignition coil,shorted ignition coil,OVER ADVANCED TIMING.
Low Compression-worn rings,burnt valves,blown head gasket
Sticking EGR valve
If your HC's are high your C02 will be lower than normal, o2's will be higher than normal, and CO could be high low or normal.
Sounds to me like it's your timing considering the thing's you have changed and you mentioned you had a shop "adjust your timing last" Hope this helps
QUICK STORM
B.A.M.F. BMW Tech
Re: My Sy wont pass emissions testing
AWD vehicles don't have to worry about NOX as we don't run a loaded mode test like 2wd cars/trucks. all you have to worry about is HC,CO,O2 and CO2. a good tune, high octane fuel, working cat, and no vacuum leaks should make it easy to pass.
AWD vehicles don't have to worry about NOX as we don't run a loaded mode test like 2wd cars/trucks. all you have to worry about is HC,CO,O2 and CO2. a good tune, high octane fuel, working cat, and no vacuum leaks should make it easy to pass.