Negative LTFT

chris' speed 3

chris' speed 3

Greenie N00B Member
Greenie Member
ENGINE/DRIVABILITY

Year/Make/Model: 2010 mazdaspeed 3
Mileage: 225k km, rebuilt oem spec engine has 20k
Location: MTL
Concern: -14 LTFT at idle and around -9,-6 while driving
DTC's: p0455 (Evap gross leak)
Modifications: bone stock (for now)
ECU/Tuning Software: AP
Tuner: not tuned
Is the concern intermittent? no
Can you duplicate the concern? yes

So having issues with negative ltft, I don't know how long this has been going on as I just recently installed my accessport with a stage 0 map from cobb in preparation for some mods and a tune from justin.

I have been having a long crank issue intermittently mostly when the engine is warm since i bought the car in july 23'. Spark plugs are good and gapped at 0.026 and injectors were serviced when the engine was put in, seals were replaced with oem seals.

I'm thinking an injector is leaking as that would explain the long crank as well as the negative ltft, just don't want to spend money on seals if it could be something else like the evaporator system maybe
 
Kind of, i have a damond 3.5" on the way, also doing the pcv and adding an occ and some other stuff so whole intake system is coming off so i used windex on all the connections and everything looked good, i don't have an actual tester

But the evap code, Ive seen a lot of threads (not speed threads) saying the purge valve could cause something like this but im unsure of what the right way to test it is
 
So no you didn't... Windex won't bubble why would you try that? (Don't answer this)

Evap leak could be gas cap seal failing inspect that too
 
disassembled the whole intake, cleaned everything, cleaned the maf, reset ecu and everything seems fine now I've put 120km on it since and trims are max -6 now
 
chris' speed 3 said:
Very tempted to answer but i won't lol

And I have 2 extra oem gas caps that i tried swapping and didn't change, evap code came back

does this look like a good kit?

https://www.amazon.ca/CWTRLPC-Charg...show_all_btm?ie=UTF8&reviewerType=all_reviews
Click to expand...
No, you can build one out of a PVC end cap and a silicone coupler for less. I am assuming you have a compressor? As well as boost leak testing a smoke tester is very handy for finding leaks. That being said the smoke test and the pressurized boost leak test serve similar functions but are different tests.
 
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