fuel/air ratio problem

[robbie]

I did the ECU diagnosis thing and the truck's running more than 5% too rich.

 

Background of my 94:

I recently changed the camshaft to Euro spec ones from Nissan.

Adjusted timing to 15 degrees BTDC.

Great power across the band where I feel like I can race cars like civics and integras as long as it's under 75 mph.

The truck runs very strong now.

 

But, my mpg dropped more than 3 mpg. I used to get around 19 to 20 mpg driving very conservatively in city/hwy combined... I tried driving the same conservative way and I now barely get 16 mpg. The funny thing is that I still get 16 mpg when I drive hard.

 

How do I adjust the fuel/air ratio? Do I have to get a new computer? Get it reprogrammed? I'm certain everything else is running fine... no problems reported on ECU diagnosis. I also changed just about everything that can be changed on the truck including new oxygen sensor, new timing belt, drive belts, everything that can be changed while doing a T-belt job, h20 pump, radiator, all new hoses, cleaned out plenum, throttlebody, new ecg valve, new sparkplugs and thicker 8 mm wires, fairly new k&n type air filter, cleaned out maf sensor, fairly new thorley headers, borla catbacks, checked all fluid levels.

 

Any help would be greatly appreciated.

[robbie]

well, I took the truck in to my mechanic today and he tells me that there's no way to adjust the fuel/air mixture unless I get a new ecu computer or get it reprogrammed. I thought that he just didn't know enough about pathfinders but by the non-reponse to my question/problem in the forum I guess it's safe to assume he is right.

 

well... thanks for those who looked at this thread.