1993 240sx wont start!

[countrytuner]

Hi everyone, this is my first post to the forum and i am in serious need of help. I recently acquired a 93 240 with the ka24de engine. The engine will not run. I have been doing test all day. There is spark, timing is correct, fuel pump is working, injectors work, but it still wont start. It can be kept running by squirting raw fuel into the intake so my problem has to be fuel related. Somewhere between the ecu and the injectors something is getting all out of sync. Also, the ecu is giving me trouble code 34 for the knock sensor, but this could be due to the rough idling i was getting with the squirt bottle approach. Any help would be much appreciated.

[Rb240Coupe]

Try crankn it then checc ur spark plugs to see if u smell fuel

also u can disconnect your fuel line then crank and have a buddy see if fuel is coming threw the lines. If not then try bangn your fuel pump

[countrytuner]

I checked the fuel line coming from the tank and fuel goes everywhere, then i checked the return line coming from the fuel rail to the tank and fuel poured out of there too... the problem im having isnt getting the fuel to the injectors. Ive narrowed it down even more now, I am getting 12V to the injectors with the ignition on but not cranking, i am just not getting a pulse signal to my injectors. I am going to buy a noid light tomorrow and see if that is actually the problem. My question is, what causes the injectors to pulse? CAS? ECU?

[countrytuner]

tried a quick fix today. Used an ECU for a ka24e engine... ran but obviously ran like crap, now i know its the ECU thats giving me the problems with the injectors not firing, if anyone knows where i can buy an ECU for a 1993 240 with the KA24DE engine... let me know

[3SCustoms]

my buddy might have one, ill ask him 2maro and get back to you

[countrytuner]

Awesome. That would be great!

[Wc240]

FYI, the CAS sends a signal to the ecu to tell it when to spray and when to fire.good job diag'n and narrowing it down. does sound like mabe the drivers went out. let us know how it goes

[countrytuner]

Hello again,SO i got another ka24de ecu out of a running car, plugged it in, and still no injector pulse. I put the ecu for the ka24e engine back in, the engine fired right away, but obviously still runs like crap because of the difference in sensors and whatnot. Im at a complete blank again. The fact that it runs with the ecu from the single cam engine and not the dual cam engine makes absolutely no sense to me. Obviously the ecu is not sending a ground signal to the injectors to pulse with the correct ecu, but it is with the wrong ecu??? Does anybody have any idea what might be causing this? My first idea was wiring, but even that doesnt make sense since the injectors pulse fine with the single cam ecu. Is there something I am missing here? Or do i have yet another dual cam ecu that has toast drivers for the injectors?

[vdub62387]

Check the wiring or starter

[1KleenS13]

Check the wiring or starter

Great advice After you check the starter, make sure you dont have a blown tail light bulb

OP you are on the right track, do you have access to a scan-tool of sorts? Unplug you coolant sensor and see if it will start the car (will default to around -40 degrees and tell the computer to dump fuel into the engine) Check the things that tell the computer how much fuel is needed, TPS, MAF, Coolant temp....... Keep hammering on it, you'll find the problem.

[countrytuner]

hey all, madea breakthrough tonight... got the thing timed properly... DUH!!... oh well. The engine runs now... well kinda. It wont start unless primed with fuel sprayed into the intake, and it only revs up to 4000 RPM... not easily i might add. The throttle is linear up until about quarter throttle, then the more throttle you give it, the crappier it runs and the lower your rpms get (levels out to about 2500 RPM at full throttle with serious missing issues). I've got a number of things to try now. I know its down on compression on cylinders 1, 3, and 4. I dumped a bunch of avgas/premium gas into the tank. It also has a really sloppy idle (idles at around 600 RPM, but will fluctuate between 400 and 800). I havent pulled any codes off of the ecu yet, thats tomrrows job. Anybody have any pointers or ideas on where a good place to start would be? besides obviously pistons and rings with an overbore to get the compression back up. Top end is perfect, valve seats and guides are great. Camshafts and distributor timing is perfect now.

[1KleenS13]

Maybe a flaky TPS sensor. Get the codes out of the ecu and go from there.

[countrytuner]

hey, so i just pulled the codes and im getting codes 14 and 34.. which i believe to be the vehicle speed sensor and the knock sensor... ?

[md4040s]

hey in case you haven't already done so, make sure the mafs wiring is all good.