KA-T misfire.... help!

[Garber]

91 240sx hatch with ka24de-t.

friend #1 built the car and never had it tuned, got deployed and sold it to friend #2 for cheap because he needed money. Friend #2 didnt really want another project so he sold it to me for cheap. i went and looked at it a few weeks ago and it idled fine, and it was really clean. i made a down payment on it. it was just running reallly rich because of no tune.

he got the title last week and we transferred it. he said he didnt drive it since i made the down payment but it misfired at idle, and the whole time i drove it home it misfired.





pulled the plugs. cylinder two was wet so i replaced them with brand new ones. that didnt help. cylinder two is not firing at all. the plug looks brand new when i pulled it out again, minus being soaked in gasoline (the others are already brown from it running rich). grounding the plug on the valve cover i can see plenty of spark in the daylight when the car is turned over. i check the injector with an ohm-meter and it read 11.8 which is good. i dont know what to check next. any ideas?

i was scheduled to get it tuned today but i couldnt because of the misfire.

[j20accord00]

while its running have you unplugged #2 injector?

my friend had an issue with one of his injectors, they were 550s and it just stuck open dumping too much fuel. he pulled the injector clip off and it made no difference at idle while it was running.

you should list more about the car, injectors, maf, ect...you shouldn't be driving it without a tune at all..and if its not tune with bigger injectors..well theres some of your misfire problems

theres alot of factors that take into place...post up a pic of th engine setup too

btw what are you tuning it with?

[Garber]

i unplugged injector #2 and it made no difference. i figured that didnt matter because it wasnt firing anyway? i dunno.

im working on getting a mod list. he told me a few weeks ago but i forget most of them. he is slow at getting back to me but i will update as soon as i know.

what i know:

ka24det completely rebuilt 15k ago
garret td04
bigger injectors (not sure what time)
chipped ecu for a t3/t4 turbo (thats what he told me lol)
safc-2 (which is what needs tuned)



http://img718.imageshack.us/img718/8485/55129842.jpg

[j20accord00]

just looking at it quickly i see 3 things that are wrong...one the maf is too close to the turbo..

2. the ccv needs to be vented back into the intake behind the maf and that hose that is going the intake in front of the maf should be moved to the cold pipe.

that will fix some problems..but you still need to figure out what else is going on,

dont waste your time with that safc. there is so much more tuning tools then that.

it seems you are having an injector issue. After you get the info you need, find out what exactly it is tuned for and who tuned it.

fix them 3 things first. and check the timing...and while your at it make a boost leak tester and see if you have any leaks.

Also check and make sure the maf is wired correctly. and what kind it is. and make sure you have an extra ground on it too

[Garber]

thanks for the advice! i want to get this cylinder firing before i starting "nitpicking" though.

how can i tell if the injector is stuck open?


this would all be so much easier with a mod list lol. will i be alright for a little while with that safc-2?

[j20accord00]

are you trying to use this car as a dd?

I would wait till you find out more about the car and what tune it has.

injector wise, that im not 100% on, but from experience that Ive seen with my buddies car, it was flooding with fuel..it was everywhere..literally coming out of the exhaust.

and it ran and missed like crazy..if you can find out what injectors it has maybe you can try putting another one in there.

[importdude]

check your maf wiring

to check if the injectors are leaking
pull the rail up in the air and turn on ACC power and let the fuel pump prime
if its leaking ull see gas come out of the bottom of the injectors

remove the sAFC

[Garber]

hmmm doesnt sound like an injector then. it drove half decend besides a sligth vibration from the misfire.


the plan is eventually to dd it. i wont before it is safe though.


any way to check the dizzy?

why do you suggest checking the maf wiring? and what should i look for?

what is the danger of having the maf too close to the turbo?

[Garber]

the injector o-ring was leaking bad enough to saturate the cylinder so it couldn't fire. got it taken care of. thanks guys.


look for many new threads to come as i figure out whats going on with this thing. im gonna try to dial in the a/f's tomorrow

[DeatschWerks]

I would take heed of the warnings about the MAF, you should have about 18"-24" of piping between the turbo and the intake for the MAF to function properly. The word of caution about checking the wiring on the MAF is because it has been a common issue of them being wired improperly because of the varieties of MAF meters being used with turbo additions and swaps.