Exhaust leak on a 4.9
#1
Exhaust leak on a 4.9
Would this cause a moderate miss and a slight loss of power? While going thru my checklist of wtf could be causing my miss, I not only heard the exh leak this time, but I saw where it was coming out-#2/#3 cyl area. There was a slight hesitation when I goosed the butterfly, like the rpms dropped a 100 or 2 for a split second, then would catch itself and increase normally. But if I just eased into it, it wouldn't hesitate. Its also about 30-40 degrees colder out now compared to last time I drove the truck, and this diagnosis was done during initial startup. Would I be ok putting around 800 miles on her this weekend/next week without having to worry too much about something catastrophic happening with this exh leak?
#2
An exhaust leak shouldnt do much. It'll make some noise, and possible crackle or pop from any unburnt fuel mixing with fresh air then burning in the exhaust pipe. If its a small leak drive it and fix it when you can.
A vacuum leak on the intake side however could cause cylinders to lean out and overheat parts and cause tuning issues.
A vacuum leak on the intake side however could cause cylinders to lean out and overheat parts and cause tuning issues.
#3
if this is a carbureted motor the cold could be causing running issues when you snap on the gas. Carburetors have an accelerator pump that squirts extra fuel when you press the pedal down.
When you open the throttle the air can speed up faster than the fuel and the accelerator pump squirts the extra fuel in to compensate. A broken or mistuned accelerator pump, plus denser cold air can cause the air fuel ratio to lean out for a split second causing bogging or bad running when hitting the gas.
When you open the throttle the air can speed up faster than the fuel and the accelerator pump squirts the extra fuel in to compensate. A broken or mistuned accelerator pump, plus denser cold air can cause the air fuel ratio to lean out for a split second causing bogging or bad running when hitting the gas.
#4
An exhaust leak shouldnt do much. It'll make some noise, and possible crackle or pop from any unburnt fuel mixing with fresh air then burning in the exhaust pipe. If its a small leak drive it and fix it when you can.
A vacuum leak on the intake side however could cause cylinders to lean out and overheat parts and cause tuning issues.
A vacuum leak on the intake side however could cause cylinders to lean out and overheat parts and cause tuning issues.
A failing fuel injector can also cause a misfire.
Either way you have to pull the top half of the intake to get to the problem.
Thread
Thread Starter
Forum
Replies
Last Post
bike_guy123
Bio-diesel, Propane & Alternative Diesel Engine Fuels
5
01-07-2013 11:13 PM
whiteaddiction
1994.5 - 1997 7.3L Power Stroke Diesel
13
01-16-2009 01:36 PM
Scott89-150
1987 - 1996 F150 & Larger F-Series Trucks
2
01-20-2007 11:49 AM
Ilikebigtrucks
1994.5 - 1997 7.3L Power Stroke Diesel
3
09-21-2006 12:19 PM