maft with lucas 550's hella rich

[ilco187]

I am about to just toss these injectors out and get oem 450's but on to the problem, i set the maft up as the way it should for 550cc and no matter how much i turn the dials it is still rich, i mean like new set of plugs and 3 mins of idle pull em out and pure sooty, and cylinders wet as hell. touch gas pedal during idle and it stalls then revs but with missing and popping.

set the maft up as if they were 500cc and runs fine no stalling no misses and clean burning of fuel.

what is the flow of these damn things i cant find the site that had the specs its been about 3 years since ive seen it.

fuel system is denso 150 lph fp and n/t stock fpr.

 

[ENICKB]

What are you using to tune? Also you may as well sell em on ebay and get big injectors. Also why not just run speed density? You'll be a much happier camper! I promise. Maybe try opening the BISS screw to add some air to that mix? Hope this helps.

 

[92AWDHX40]

How are you tuning, maft and thats it, do you have a wideband, why do you say its running rich.

 

[habitatguy187]

The nt fpr has a base pressure of somewheres around 47psi if I remember....10psi more than a stock manual fpr. Hence why you're running rich and flooding out your plugs.

 

[ilco187]

Yeah i just have the maft, im more of a set it and forget it kinda guy i just add basic mods that really dont need much of tuning but its rich as it backfires and pops at idle and plugs are 3 mins of idle old and fouled in carbon 3rd set this month and wet in fuel so are the pistons.

on my last 1g i used this same maft with 450's and a wally 255 it was fine, ever since i got a n/t fpr and 550's its been a flooding hell.

probably gonna sell the 550's and go back 450's but get 2g 450's they have a better spray pattern, and 36 psi oem fpr like my old 1g and see what happens. save the bigger stuff for when i have link in the future.

also i have been told by a somewhat but not dsm expert that a bad knock sensor can cause rich conditions? is that right or BS.

 

[habitatguy187]

also i have been told by a somewhat but not dsm expert that a bad knock sensor can cause rich conditions? is that right or BS.

If it's throwing a code for the knock sensor then the ecu will put your car in "limp mode" - making it really rich so that you don't accidentally knock and blow it up. If no code though then no limp mode.