98 Ka24DET Frontier

[TRacing]

hey everyone.ive recently gone out and turboed my 98 Frontier. im currently running 8PSI on a stock block. the motor is running EXTREAM rich. does anyone have any idea how to solve this problem. i was thinking a new map senors but i can only find 1 bars for it and from what ive been told the computer wont except a 2 or 3 bar map senors. if anyone has an ideas please help me out

[TurboKA37]

what type of set up do you have? what are you doing for fuel management?

[Craving4Boost]

u have any pics? i wanna see

[fiznat]

yep it really depends on what you're using to manage your fuel...

Is the frontier KA actually MAP sensed? Didnt know that... KAs for the 240sx are MAF sensed from the factory. As far as finding a 2 or 3 bar MAP, GM has them-- I can get you part numbers if you wish.

[TRacing]

it has Both a MAP (which is a 1 bar) and a MAF. the MAF is built in to the side of the throttle body and the MAP is off to the side of the motor compartment. I have a 3 bar MAP off an 88 SVO turbo mustang. i havnt wired it up yet, i wasnt sure if it would work. if a GM one will work for sure then please send the part number and ill go out and give it a try. the fuel management system is complete stock. i havnt touched it yet. it seems to have more then enough fuel delevery i just need to find a way to lean it back a bit. as soon as the motor hits about 3K on the tach my air fuel gauge goes from about mid way to full rich and if i get on it hard u can see it let out a big black cloud of carbon. soo i know its getting more then enough fuel. some ppl have told me upgrade the fuel system some have told me replace the map senors. any ideas????

[jacob360]

I would do some more research into how the system meters air flow. I should know this, being a tech at a Nissan dealership and all, but I just started, and haven't had to deal with it yet. But if it has a MAF, that's what is measuring airflow. The MAP would most likely be used for OBDII diagnostics. I'll see what I can find in our information system.

[TRacing]

That would be great thanks alot.

[fiznat]

For your setup I would look into picking something like a S-AFC up. Upgrading the MAP wont do anything for you I dont think, and with the SAFC (~$200 I beleive?), you will have the ability to tune your fuel mixture back and forth in order to get the right mix. You really cant just throw on a turbo and expect the AFR to be perfect, doesnt work that way on EFI cars...

Like I said I really dont think upgrading the MAP will do anything for you (I dont even think it would work at all without a recalibration of some sort), but the GM part numbers are:

GM 1 Bar: P/N 12247561 -13.1PSIg (11kPA) to 0.7PSIg (106kPA)GM 1 Bar: P/N 12219927 -14.7PSIg (0kPA) to 0.5PSIg (105kPA)GM 1 Bar: P/N 12219931 -12.5PSIg (15kPA) to 0.8PSIg (107kPA)GM 2 Bar: P/N 12247571 -13.5PSIg (8kPA) to 15PSIg (205kPA)GM 2 Bar: P/N 12223851 -11.1PSIg (25kPA) to 25.1PSIg (275kPA)GM 3 Bar: P/N 12223861 -14.4PSIg (2kPA) to 31.1PSIg (316kPA)*GM 3 Bar: P/N 12219935 -8.3PSIg (44kPA) to 30.8PSIg (314kPA)GM 3 Bar: P/N 16040749 -13.1PSIg (11kPA) to 29.3PSIg (303.4kPA)

*I'm using this one on my setup

[2s4x0]

Hey NICK! I went to school with you punk!

[Structure240sx]

does the truck stumble at all in boost? get a wideband or get on a dyno to really see what our afr's are

[WDRacing]

Just so I understand whats going on here...Your running 8psi on stock fuel inecjtors of a KA24DE in your Frontier and your telling me that it's running rich?

I'm leaning towards saying thats impossible. The stock injectors will lean out a motor badly over 5 psi. So 8 is just to much, especially to be running rich.

If your using a narrow band AF meter you need to throw it in the trash....they are worthless at best. Beg barrow or steal a wideband and re-measure.

WD

[TRacing]

Ok to ans the last few post. Yes the truck is RUNNING EXTREAMLY RICH. My tail pipe is complete Black with carbon and on my drive way u can see where ive stopped and let the motor/turbo spool down cuz the tail pipe points right down to the ground and is leaving a nice lil black circle everywhere on my drive way. And its not oil incase anyone was thinking that. Ive had a buddy roll behind me and he could smell fuel coming out the pipes every time I got on it hard that’s how rich its running. The truck runs great when its in boost. it was stumbling for a lil while but the cause of that was cuz of a blown gasket between the turbo and the manifold, but now that has been fix its running beautifully, while in the boost range other then the fact is drinking my fuel. If the new MAP senors wont do anything then ill just return the 3 BAR I got off the stang. Im looking round now for an APEX S-AFC if any one has one for sale let me know cuz that’s most def on my parts list. along with a bunch of other parts. As for the air fuel gauge it is a narrow band and yes I know its not the most accurate thing but I just use it to make sure it doesn’t lean out the motor. As soon as im ready to really tune this thing im goin to take it to school and put it on the DYNO. And hook it up to all the test and metering computer they have. I would be happy to post pics I just don’t know how to. Thanks a lot guys for the help and if anyone comes up with any more idea please let me know. And when I do dyno it ill be happy to post the final results of it. ive gone light to light with a few ppl my best right now is holding door to door with a new GT Stang. But then again it RAN perfectly on that go. It has it good and bad days it seems like. but its a lot and I mean A LOT better then it was stock.

Ps hey Taylor long time no see. How have you been?

[2s4x0]

Good, i totaled my ricetegra finally. I was looking for a way to get rid of that car, luckily i ran in to the back of a f-150, got insurance money, and got myself a 98 240. Did you put the turbo on yourself???

[LEMHEAD16]

Post your set-up if you want a better answer. Something sounds odd

[j-z]

does anyone know the map system that this guy has on his truck? wondering because i used to own a boosted prelude and hondas run map sensors. if theres one thing i know about map sensors, its that they dont like to see boost. are you getting any check engine lights? in hondas, whenever the map sees boost the ecu goes nuts and runs in safe mode by dumping alot of fuel in and backing timing off. sounds like this could be your problem because you said its really rich under boost, and i know, along with others, that with your stock fuel system you shouldnt be seeing any black smoke out your tailpipe. the quick fix for this problem on hondas is called a missing link. its like a check valve sort of that you place in line with the vacuum hose running to the map sensor, so you can boost without the map knowing and having it go into safe mode. hope this helps. by the way, what color is this fronteir so i can keep an eye out for this thing.

[TRacing]

Ive been messing with the map senor and the lines goin to it. i figured the same thing about the boost and my friend had come to the same conclusion about the truck running in safe mode. what my plan is to see what happens once i get down playin with the map circuit. i think the next parts on my need list is an adjustable fuel reg and the APEXI S-AFC controller. that should allow me to fix this fuel problem. I know the thing is getting more then enough fuel, Does anyone know what size injectors come with a stock frontier cuz i know the pump produces 34psi of fuel pressure and thats more then enough. my buddys SVO runs 15 PSI of boost and has 36 PSI of fuel pressure i just dont know what size injector the thing has. the truck is a silver and its been lowered about 3 inchs all the way around. it needs a nice set of rims tho. hopefully a B-day gift from me to me. and Taylor to ans ur question Me and Loren managed to drop in the turbo and custom fab all the intake and exhaust along with the oil feed and return in about a week. not to shabby i think for something thats never really been done or atleast no write direction on what to do and how to do it. if anyone would tell me how to post a pic on here ill be happy to post some pics of the turbo and the truck.

[C-Kwik]

I'd suspect that the Frontier has similar sized injectors as the KA in the 240SX. 260-270cc. Which would likely mean you are going tu run dangerously lean at anything over about 4 psi of boost. I'm curious as to what other fuel system changes you made(if any) to keep from getting detonation at 8 psi of boost.

[C-Kwik]

all you need is an ECU fron JWT, some 555injectors and Z32MAF. 22psi, no problem...

You're missing the point. TRacing is indicating his fuel system is stock. I wasn't asking what is needed, but how he manages to get enough fuel to his turbo motor using a stock fuel system...

[TRacing]

if from what all ur saying about it should be running lean is correct then i dont know how its running the way it is. ive never heard it knock or detinate while driving. I just ordered a Apexi S-AFC soo that should be here in a day or 2 and if my math is right then my truck should have 24 pound stock injectors. im probly goin to update those and get a ajustable fuel pressure. but i cant explain why its running so well. other then it consuming so much fuel

[underpowered]

going turbo has its price, don't you think?

[Nismo_Freak]

if from what all ur saying about it should be running lean is correct then i dont know how its running the way it is. ive never heard it knock or detinate while driving. I just ordered a Apexi S-AFC soo that should be here in a day or 2 and if my math is right then my truck should have 24 pound stock injectors. im probly goin to update those and get a ajustable fuel pressure. but i cant explain why its running so well. other then it consuming so much fuel

If your truck isn't detonating it is solely because you have no timing.

It is physically impossible for your injectors to flow enough fuel to support the engine. Much less the fuel pump to maintain the correct amount of flow at 51 psi of line pressure.

Your engine is on the brink of exploding. Fix the fuel system.

[C-Kwik]

your ECU maybe confused its functioning with the turbo. It was not made for turbo. I had same problem with my S14, and APEX safc maybe not the best solution; I have one for sale, new $250.

The ECU certainly doesn't know there is a turbo in there, but it will be able to read the additional airflow up to the MAF's limit. As a result more fuel will be added in proportion to the amount of measured air until either the fuel injectors or the MAF's limits are reaced...whichever comes first. I ran an E-Manage on an S14 powered by a T04B for more than a year and it ran just fine. Any problems I had were not problems with nor was it a result of the ECU or fuel delivery.

[ka24de-tier]

Hey I wanted to know what intake Manifold you used. I also have a frontier n want to turbo aswell.