hey guys, before i installed my walbro 225 fuel pump, my sr20DE (yes, the N/a version of the rwd sr20det, just with higher compression) in my s13 was getting 27mpg in the city. but with the walbro, im getting 19. i think im running super rich. ehh.. help?

 

you shouldn't be running any different with just a fuel pump, because your fuel pressure regulator still regulates how much fuel is being consumed.


check fuel pressure to make sure the FPR is working right. you could also check the MAFs/connections, plugs, injectors, o2 sensor and coolant temp sensor.

something sounds like its being sketchy causing it to run rich. could be a sensor, perhaps the mafs is getting some wierd readings or bad connection.


wideband o2 sensor would help diagnose if its truly rich or not.

 

do you think its a good idea to just get a an entire new maf for it? its weird becasue when i lift a wire connected to it, my whole motor sputters and stops.

 

to the MAFs?

if so, inspect the wires right where they go into the plug, look for tiny tears or bends, that's where mine broke off long ago too just from being bent and the wires get brittle and hard over time and break off.

if that looks okay, peel the harness off and go back as far as you can until you find any wires exposed or broken, or at least until it gets bundled in with other portions of the harness (i.e. when it gets thicker). if it seems ok until then, it might be near the ecu or anywhere in the harness.

also check the mafs itself look to see if the hotwire probe (thin metal strip inside the element) is broken or bent or something.