I30 engine surges and poor fule economy

[dskorski]

I have a 1998 Infiniti I30 with only 40K miles. Recently, there seems to be a surge and back off of the engine when climbing small grades (any gear and any speed). The effect is fairly subtle and passengers don't seem to notice. Also, the fuel economy has changed - from approximately 340 miles per tankful to only 300. There is no indication of a "check engine" light or any other problem. The car starts fine and accelerates without hesitation. The problem is most apparent when trying to maintain a steady speed while going up a slight grade.

Any help or thoughts would be most appreciated.

[gniknave]

First of all Welcome To NICO!

I used to own a 99 I30 and had the same problem. I found it only appeared when using 87 grade fuel. I filled up with premium Chevron w/ Techron, and added a can of BG44k to the fillup, and that did it for me. You might get some better answers if you post in the Maxima/I30 forum

[dskorski]

I always use the premium fuel and have added different fuel injector cleaners as well. I think the problem is a bad coil or plug. They are just so hard to get to, at least the back three.

[gniknave]

Try owning a Q45...you aint even seen hard yet