Car hesitating... could it be the gas?

[emdoller]

I've read most of the posts on hesitation but before I go through the analysis I wanted to know if it could simply be my fuel.

The last time I drove the car was about 2 months ago when it ran great. The car has about 1/2 a tank of gas. It has gotten cold here and I'm wondering if I could simply have some condensation causing this.

Has anyone had this happen?

I just added some dry gas and will let the car sit a day. I guess I could always drive it around, burn up the gas and refill to be sure.

What do you think? BTW, it's a 95 with 15K miles.

Ed

 

[goldNSX]

Gas is capable to neutralize condensation to a certain degree. But how cold is cold? Does your car stay outside?
After a longer time of sitting around it could be the injectors needing a cleaning. Maybe an injector cleaner and fresh gas will help. Checking the o2-sensors and fuel pump are two very cheap ways of diagnosis.

 

[emdoller]

Gas is capable to neutralize condensation to a certain degree. But how cold is cold? Does your car stay outside?
After a longer time of sitting around it could be the injectors needing a cleaning. Maybe an injector cleaner and fresh gas will help. Checking the o2-sensors and fuel pump are two very cheap ways of diagnosis.

Car is garaged and its gotten into the low 40's at night. I just added injector cleaner so I'll let that run through.

When you say check the o2 sensors, I assume you are referring to the method described of disconnecting them to se if the issue goes away?

How do you check the fuel pump?

Thanks!
Ed

 

[emdoller]

I'm not sure I know which connectors to disconnect to test the o2 sensors. If I'm standing on the passenger side looking towards the front, I see one connector near the bottom, passenger side, of the valve cover. I tried to disconnect it by pushing on the "tab" and pulling it out and I could not get it. I was worried about breaking it, and with not being sure that was the right one anyway, stopped.

On the rear of the engine, I could see one clip that seemed hard to get at with two hands so I'm not sure if it's the right one and if it is how I'm going to get that apart with one hand.

I crawled under the back and could see the two sensors and they seemed to lead to two clips that again did not seem easy to get at.

Suggestions?

Ed

 

[goldNSX]

Just follow Larry Bastanza's recommendation. You can't break them easily.

Fuel pump: Short the cable to the fuel resistor.

Good luck!

 

[doc_tai]

you have to pull it out the bracket first before you can unplug it

 

[emdoller]

you have to pull it out the bracket first before you can unplug it

for both of them? do i need to remove any part of the valve cover plastics?

 

[emdoller]

Update:

Shorted to fuel pump resistor and no change.

I disconnected the front o2 sensor and no change. Not easy to get the back one and I'm not sure this is it.

It seems like it's only running on 5 cylinders but I'm not sure. I've decided to pull the spark plug coils and check them out.

I'll keep you posted,

Ed

 

[emdoller]

Update: Pulled all coils and checked resistance. All 1.2 ohms

Spark plugs look ok but since I have them out I will replace.

I was able to pull off the other o2 sensor and once I put the plugs in and the coils back on give it a test...

I'm not too optimistic at this point but we will see.

Ed

 

[emdoller]

Update: I put new plugs in, put it back together and left both o2 sensors off and the car runs great.

I then hooked the sensors back up, cleared the CEL code, crossed my fingers, and the car still runs great.

I'm really not sure why letting the car sit for 2 months would do this but it seems to be fixed. That is, I've never had a car do this. The coils looked like new and everything was as dry as could be. Any ideas?

Ed

 

[goldNSX]

Well, any part can go bad any time. I'm glad you've found it that quick. Forget about the cause and enjoy your car.

 

[emdoller]

Thanks again for your help... I really appreciate it!!