Once in a while Im getting a cough or pop. It sounds more like out the exhaust than back up through the intake. Seems to always do it after decelerating to stop at a traffic light or whatever, then as soon as I start to accelerate it happens. It only happens once in a while, but enough to have me concerned. It NEVER happens while holding consistent speed or under heavy acceleration. Truck always idles perfect and other than the problem, runs very smooth.
TRUCK IS COUGHING
- Thread starter stealth78
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TheMoparConnection
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sounds like a bad tps sensor
Heart Attack
Full Access Member
Do you use a K&N Filter? If you do, what happens is when it doesnt dry properlly the oils get on the TPS sensor and causes your throttle to act weird. buy a tps cleaning spray and pull your tps sensor out and clean it.
JeffBoyette
Full Access Member
Your thinking of iat sensor, not tps. They don't make a cleaner for either but you can use maf sensor cleaner to clean the iat but its normally not needed and is unlikely to cause this random hiccup. The oil sprays and coats the iat sensor throwing off the reading of proper air temp. Your right that k&n interferes with vehicles sensors when over oiled. However it is with vehicles that have MAF sensors. We dont. It makes it think the air is hotter, because it is a small heating element and measures the voltage needed to maintain that temp. When it gets oil burnt on the element it reacts slowly and measures the temp incorrectly. The iat sensor we have is a simple thermometer.
The tps doesn't get dirty, its enclosed. It acts like a potentiometer, the terminals inside have trouble making contact throwing off the throttle position reading. Usually it is random, effected by temperature, and will cause dead spots mid throttle. During throttle transitions it will cause bucking or areas of poor throttle response. More often it provides the incorrect resistance at idle. The coughing symptoms are normally seen more when the vehicle is warm and in closed loop mode, monitoring the various sensors. However a hanging or irratic idle is also seen on both open and closed loop.
The problem you are having is because the computer thinks you either floored the throttle and it instantly dumps more fuel but there isn't enough air because the throttle body blades didn't really move. You let off the throttle to come to a stop and the computer thinks you still have it partially open. The cough you are hearing is a quick flood of fuel and/or spark timing fluctuation causing a small backfire of puddled unburned fuel in the exhaust.
Iat- intake air temp
Iac- idle air control
Maf- mass air flow... We don't have.
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