Black smoke at WOT
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Black smoke at WOT
I am hoping you all can give me a few suggestions that might help me determine why I have black smoke at WOT.
My mods are listed below:
TEA stage 1.5 5.3L heads milled .015
TR224/114 cam
Stock length push rods
Stock (factory) timing chain
LS6 intake
30# SVO injectors
Mac headers
Ported TB
De-screened stock MAF
Fast Toys Ram Air kit
ASP pulley
Built 4L60E with a PT4000 stall converter
I use EFILive, Innovate Motorsports WB O2 meter, and LS1Edit to tune the car.
LTFT are between -.8 and -10 while at cruse and 0 at WOT.
WOT AFR bounces around between 12.7 and 13.1 depending on what gear and RPM.
My AFR looks good. I have confirmed proper operation of the WB on other cars.
I know black smoke is not always an indication of a rich condition. It can also be an indication of incomplete combustion.
Is it possible that maybe my pushrods are too long and are not allowing the valves to close completely?
Any suggestions?
Thanks
John
My mods are listed below:
TEA stage 1.5 5.3L heads milled .015
TR224/114 cam
Stock length push rods
Stock (factory) timing chain
LS6 intake
30# SVO injectors
Mac headers
Ported TB
De-screened stock MAF
Fast Toys Ram Air kit
ASP pulley
Built 4L60E with a PT4000 stall converter
I use EFILive, Innovate Motorsports WB O2 meter, and LS1Edit to tune the car.
LTFT are between -.8 and -10 while at cruse and 0 at WOT.
WOT AFR bounces around between 12.7 and 13.1 depending on what gear and RPM.
My AFR looks good. I have confirmed proper operation of the WB on other cars.
I know black smoke is not always an indication of a rich condition. It can also be an indication of incomplete combustion.
Is it possible that maybe my pushrods are too long and are not allowing the valves to close completely?
Any suggestions?
Thanks
John
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#9
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Thanks for the replies.
The rocker arm bolt threads are sealed and COT is turned off.
It blows black smoke as long as it is at WOT. What is strange is that if I am at 70%-80% WOT (but still in PE) there is no smoke. When I go 100% TP is when it smokes (black). The car seems to smoke more towards the end of the run or just more in 3rd gear. This kind of points to a bad MAF not reading the airflow correctly at the higher levels. However I would think that the wide band O2 would show this.
I have the WB in the right hand side of the exhaust. Maybe I have a bad injector on the left hand side and this is causing the black smoke. I will swap the WB to the left side and see what the AFR is,
My timing is set at the stock 28 degrees. When I go WOT there is no (<1) KR in 1st or 2nd gear but as soon as it hits 3rd gear I get 1.5 to 2.5 degrees of KR.
The rocker arm bolt threads are sealed and COT is turned off.
It blows black smoke as long as it is at WOT. What is strange is that if I am at 70%-80% WOT (but still in PE) there is no smoke. When I go 100% TP is when it smokes (black). The car seems to smoke more towards the end of the run or just more in 3rd gear. This kind of points to a bad MAF not reading the airflow correctly at the higher levels. However I would think that the wide band O2 would show this.
I have the WB in the right hand side of the exhaust. Maybe I have a bad injector on the left hand side and this is causing the black smoke. I will swap the WB to the left side and see what the AFR is,
My timing is set at the stock 28 degrees. When I go WOT there is no (<1) KR in 1st or 2nd gear but as soon as it hits 3rd gear I get 1.5 to 2.5 degrees of KR.