so im having a wierd problem and im not sure what the cause of it is.. if i take off going through all my gears the car drives fine... but when im cruising in a gear and accelerate harder my car begins to bog and back fire.. im tuned to high 11's-low 12's AFR... but once i get on it it leans out to anywhere from 13.x-18.x.... when im in the 13.x range the car moves but anything else it jsut sits and backfires..


Im also getting getting about 10mpg which i dont understand.. i know i have a hbp and all but when i was on my base map when the engine was breaking in i was getting about 18mpg... then i had a defected tune bc the dyno broke on me, but i was still tuned rich, cant remember exactly but still over 16mpg... finally got the car for its real tune about 800 miles ago and even after he took out 30% of the fuel, im getting worse mpg?

Therefore I thought it was due to a leaky primary injectors but i disconnected them and tried starting the car and it didnt start so i ruled that out... now idk where to go from here.. Another side note we took out the huge resistor by the ignition.. idk if thats relevant... could this be a fuel pump related issue? and my fuel pump isnt keeping up with the transition of the 550 to 1600?

Other symptoms not sure if theyre relevant...
white smoke from exhaust.. im thinking either because im too rich or from premix...
hard start ups- sometimes it feels like im almost flooding the engine-could be in my head, could be the HBP....

heres a list of my mods..
half bridge port- ~2500 mi
550/1600
apexi pfc
greddy fmic
stock trailing coils/ fc leading coil
upgrade plug wires (forgot brand)
emissions delete
simplified vaccum
99spec twins
aem water meth
koyo rad
walbro 255 fuel pump
aeromotive fpr
innovate Wideband- DB gauge

 

Swap your injectors, best bet. I've had the hesitation issue in the past, generally it's due to not enough spark, or too much fuel, or both. if you're using too much premix, you'll also get breakup and hesitation, as well as smoke. You can try leaning out a bit of your premix, as well as swapping injectors with a good or clean set. 550's are easy to come by.

 

is it only when you make slight throttle movements while cruising? it could be accel enrichment settings

 

+1 on accel enrichment

 

Mazda Dealer here in Japan told me its probably a Solenoid from your Rats Nest or Solenoid Rack.

Not sure what year you have.....but I am changing mine now.

Looks like this.
Also changing all the hoses.

 

Check out your TPS voltages.
Download the map, zip it, go to the PFC forum, post it.
Log the event with ADVANCE functions and post it.

Having half bridge with stock twins is a poor combination!