Hesitation/Pause issue.

[ssholland1]

Hello,
2001 Pathinder LE with 230K miles, AT. I have a perplexing situation. It has been my observation that anytime and every time I have replaced the ECM (twice), MAF (twice), TPS (twice) my pathfinder ran great out of the box. Almost like new. In fact the last time, 1 week, I replaced the MAF for the second time, the car ran better than new. I was impressed.
However, after 2-3 days of splendid driving experience, I get a slight hesitation or pause. At first it is very slight. The hesitation becomes more pronounced and significant. It usually occurs while driving at 15mph and often occurs when making a turn. Sometime, after a while, it can become a jerky hesitation. At one point, I had several mechanics look at it, and from what I remember hem all saying it was consensus, the transmission was the cause. However, this last go around, I seriously questioned that wisdom. I think there must be an electrical short somewhere. I guess I wanted to know if anyone else had this problem or heard of it. I appreciate any responses. Thank you.

[Towncivilian]

Have you changed the fuel filter within the past two years? How's the transmission fluid level and condition?

Why have you replaced all those things twice? You must have wasted a ton of money on that. I feel that your prior mechanics were incompetent.

Welcome to NICO.

[ssholland1]

Whoa...ease up on my mechanic...he's all I can afford....incompetent?, probably. I do like your idea on the fuel filter. It has been over two years sicne it was replaced. I will, er, ask my mechanic to check into it. Also, do the injectors ever need to be cleaned?

Have you changed the fuel filter within the past two years? How's the transmission fluid level and condition?

Why have you replaced all those things twice? You must have wasted a ton of money on that. I feel that your prior mechanics were incompetent.

Welcome to NICO.

[ssholland1]

SOLVED. I wanted to circle back and let everyone know that 100% went away when I switched to Non-ethanol gasoline. Zero surges or hesitation. Ethanol gasoline is such a farce.

[Towncivilian]

Interesting that non-ethanol fuel can have such an adverse effect. I've noticed slightly increased performance and fuel economy with non-ethanol fuel, but the difficulty of obtaining it and increased price does not outweigh the cost difference over 93 octane ethanol fuel.

Have you tried any fuel system cleaners? Chevron Techron is an effective cleaner which contains PEA (polyether amines) which has been proven to clean effectively without leaving its own deposits behind like solvent based cleaners would.

Thanks for posting your findings!

[zach7685]

I would think something else is a problem