Good Morning Guys,
Son's car. 96 Sentra with auto trans. 4cyl - I believe this is the B14 engine. 165k miles.
From cold start: The idle sits at approx. 1400 rpm all the time. When giving it gas going down the road, it runs pretty well, but when letting off the gas to coast, the idle will surge up and down a couple of times before return to the previous (high I know) figure.
Hot restart: After letting it sit long enough to go in and pick up a couple of items at a grocery store for example, it either won't restart at all or if it does, it misses and runs rich as if it's flooded, but no amount of throttle input will cause it to clear and begin running normally again. The only way to get things "right" again is to wait a couple of hours to allow everything to cool down.
What I've done: Cleaned IAC valve with carb spray, wasn't really gunked up though. Cleaned MAF sensor with MAF sensor cleaner. Again, not dirty looking. New plugs and plug wires. Changed fuel filter. No codes stored. I'm using the Torque pro app on my phone for code retrieval and for real time monitoring.
What I'm suspecting: Throttle position sensor. I say that because looking at the real time data last night, I saw no readout for throttle opening. I know my way around a DMM. Is there a procedure for checking the TPS via voltage readings?
Other possibilities: Distributor cap and rotor. Oil in the distributor because of a failed oil seal. O2 sensor, although again no codes are stored. Crank/cam sensor? I'm ruling out coolant temp sensor because it was reading correctly on real time data.
I'm going to be able to devote a good amount of time to this Saturday and would like to know if I'm on the right track. Thanks gentlemen.
Son's car. 96 Sentra with auto trans. 4cyl - I believe this is the B14 engine. 165k miles.
From cold start: The idle sits at approx. 1400 rpm all the time. When giving it gas going down the road, it runs pretty well, but when letting off the gas to coast, the idle will surge up and down a couple of times before return to the previous (high I know) figure.
Hot restart: After letting it sit long enough to go in and pick up a couple of items at a grocery store for example, it either won't restart at all or if it does, it misses and runs rich as if it's flooded, but no amount of throttle input will cause it to clear and begin running normally again. The only way to get things "right" again is to wait a couple of hours to allow everything to cool down.
What I've done: Cleaned IAC valve with carb spray, wasn't really gunked up though. Cleaned MAF sensor with MAF sensor cleaner. Again, not dirty looking. New plugs and plug wires. Changed fuel filter. No codes stored. I'm using the Torque pro app on my phone for code retrieval and for real time monitoring.
What I'm suspecting: Throttle position sensor. I say that because looking at the real time data last night, I saw no readout for throttle opening. I know my way around a DMM. Is there a procedure for checking the TPS via voltage readings?
Other possibilities: Distributor cap and rotor. Oil in the distributor because of a failed oil seal. O2 sensor, although again no codes are stored. Crank/cam sensor? I'm ruling out coolant temp sensor because it was reading correctly on real time data.
I'm going to be able to devote a good amount of time to this Saturday and would like to know if I'm on the right track. Thanks gentlemen.