Engine shaking + Black smoke - ALOT!!

[FUNGC]

my car is a 1992 240sx with a KA24DE engine

ok long story short...

ive taken out my engine to clean out my engine bay, and give it a fresher look. now when i put everything back together, it started, but it shook alot! ive checked for spark on all 4 cylinders, and there is. so after some time i gave up and threw in another KA24DE with lower km's and it was guaranteed to work.

but almost the same thing is going on with this engine. it shakes, but not as much. as i rev it TONS of black smoke comes out and my exhaust smells like gas. it is running very rich.

all the parts are the same that were used on both engines (e.g mafs, intake, exhaust, etc.) only the engine and it's sensors are different

im guessing that either the mafs is faulty or the cat is clogged, or my ecu is just messed.

please give me some suggestions, as i want to drive my car again. thnx

curtis

[neverlift]

man you bought another engine before checking for codes? no nothat sounds to be a bad maf.

[FUNGC]

how can i test if tha mafs is bad without trying another one?

or without using the consult tool which i dont have?

[neverlift]

multimeter ftmfwor check your ecu for codes. if you don't know how get the online fsm.

[DjPantsSpecR]

no, no, no. this is the easiest diagnoses in the world.

get a multimeter and check the resistance across all the injectors, you should have about 11-12 ohms.

now, this is just assuming you really put everything back together right, all hoses, and lines. then you just have a dead injector.

dont ask me why, but they die all the time when you remove them from the car, i have no idea why, but ive lost three or four like this.

so check that out. this is assuming youre reusing the same fram rail over and over while you swap motors, i do this this often...

[FUNGC]

ok now i cleaned tha mafs and everything and i think its messed.

it runs even ****tier than before, and when i pull off my mafs it idles the way it should. nice and smooth. now once i put back my mafs, it just bogs down and then shakes a hell lot.

does this mean that my mafs is screwed?

and dj, i how to test the injectors like that. i read that earlier and i tried it, but all my injectors have 0 resistance. i also tested the same thing on my friends S14 and its still 0 resistance.

now if i put the multimeter on the harness it will go up to like 60ohms and slowly drop down. soo i dunno what you are talking bout. care to explain your full steps carefully?

[s14_240sx]

i also tested the same thing on my friends S14 and its still 0 resistance.

THERES UR PROBLEM! You should have never brought such a sexy car near your POS!

Seriously we tried measuring the resistance on the two prongs that come out of the injector. Is that where u measure it?

[DjPantsSpecR]

yeah, you measure across the two prongs.

make sure youre on the correct ohm level. because im fairly sure its 11-12 ohms, you are probably in kohms, or something like that. so check different scales.

[FUNGC]

just tested a new mafs today, and it was the same. this is really pissing me off. i need my car to work!

what other possibilities are there?

oyea and when my fuel tank is almost dry, the car run smooth like normal. i just cant gas it hard, or it will stall.
Modified by FUNGC at 4:33 PM 10/28/2006

[turboboost]

check you aicv!!!

[FUNGC]

IACV was cleaned and asembled back together.

and my engine isnt just shaking during idle. if you keep it at say, 2000 rpm it will shake alot too. and alot of black smoke comes out.

when my tank is almost dry it seem to run smooth for some reason. i am really stumped on my situation.

[Cruz240Sx]

im not to sure on the ka24de but on the single cams theres a sensor that controll the fuel idel and ect it works off the temp senor theres a rubber boot that gets cracked n get mouisture in there n the connector doesnt make good contact u have to take it out wd40 it and slide it in and out a few times it might fix ur prob i had the same deal with my car n all the things u have done so far i did n nothin fixed it. the car was running rich and when u gased it it would studder. try that or if u can scan the comp if theres a code 13 in it then its that sensor try that man

[Dustin240]

Check the wires going in and out of your mafs for the right voltages,ground ect. Get the specs (Start the car and back probe the harness) ASAP^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^It's not your temp sensor,aicv or injectors.

[FUNGC]

replaced another different mafs (3rd one) and its still the same soo none of my mafs are faulty im guessing.

wouldnt the iacv just make it rich at idle? cause if i hold my revs up at... sayy 2000 rpm (or any) it will still shake like theres no tommorow.

car can seem to rev like a normal car, but once u hold the revs then it will start shaking.

ooyea and the black smoke is either gone or has less of it. or maybe its just the weather change in canada... i dunno

anyways MORE HELP APPRECIATED!!!

[DjPantsSpecR]

okay, im gonna throw this out there again.

check for around 12 ohms across each injector. the engine only shakes when it has cylinders out.

[FUNGC]

problem fixed. it was the ecu.

replaced it and i dont have any problems at all.

thnx for the help.