no start issue.

[drz1ll3st]

Long story short:

91 KA24de 5 spd

been building up my car. nothing crazy. ive rebuilt the head and had the timing on wrong, so thats that problem. now im getting code 11, 12, 21 which is CAS, MAF, No spark. ive never had a problem with my maf, so thats out of the picture. the CAS is in the dizzy, so i bought a used one and tested it out by spinning it while on the harness and i hear the injectors pulsing and im getting correct reading on multimeter.

timing is dead on now, so thats out of the question.

now for 21,,,, i pulled the plug out, connected it on the boot, held it by the strut tower and I SEE SPARKS!!!! but they look a bit weak and my dad saw them too while he was cranking the car. and IM GETTING FUEL! air, fuel, and spark are all there. this leads me to believe that my ecu is fried.

Besides ecu, can anyone tell me i might b overlooking something stupid. or confirm im right. ID rather be right and have it be the ecu. ill just get another one, turn my car on and call it a day.

[Lobo240sx]

First, Reseat the ECU harness. Pop the top on the ECU and check the board and pins.

[alms24sebring]

You have to look real closely too to find a burnt/shorted wire. They can be small. ECUs are generally $60-80

[drz1ll3st]

edit below

[drz1ll3st]

I bought me another ecm and its only giving me code 21 and now 34 which is knock sensor. my sparks are weak so idk if that accounts for it throwing a code
Heres what ive done:
checked power transister, fine no problems (after i checked it with the right terminals )
checked ignitor: primary ohm 1.2 (same from autozone) and secondary is readion 12.9k roughly. is this too high? fsm states it should be around 10.0 at 20deg C
checked resistor condensor: getting 2.2k ohms it should be

what i will check tomorrow is the ecm connector, maybe something is loose. i wanna pull my hair out!! i cant figure this thing out! please somebody throw some ideas in the air, ill try anything up to this point.

[drz1ll3st]

https://www.youtube.com/watch?v=PuaGZQ9 ... ata_player

Made a vid so u can see whats going on.

[Lobo240sx]

Video is set to private. Make it public.


This video is unavailable
This video is private.
Sorry about that.

[drz1ll3st]

thanks for bringing it up. its now public. I've ordered a new resistor condensor bc im not 100% sure mine works, so im just going to replace it. its only 16$ shipped to my doors.

[SX APPEAL]

About the only way to fry an ECU is if there's some kind of short in the injector circuits and you burn out an injector driver. Otherwise they VERY VERY RARELY AS IN ALMOST NEVER fail. Compare the amount of wear the rest of the system gets (Plugs, wires, cap, rotor, injectors, distributor etc...) the ECU is not your problem. More than likely (and this is not personal, its just how it happens, we've all done it) you've incorrectly assumed a part is good without testing it fully, and moved on to the next thing completely unaware. You say you had the timing wrong, did you turn the engine over while it was like this? If so, you could have bent valves in the head. Bent valves = no compression = no start.

[drz1ll3st]

Everytime i had set timing, i cranked it by hand and no problems. I cranked it slow also to feel anything, and didnt feel anything holding me back. I checked everything you mentioned. It has new plugs and wires. Two sets of distributors that check fine during the benchtest. Today i took a spark plug out, connected it to the boot, grouded it, and hadhady gf crank it. I got spark from the electrode to the tip, sp i do have spark. And all other components like ive stated have been checked as per the fsm and check out fine. I also dtarted a compression test but my battery started dying, and i got, from one to four, 180, 170, 160 140. By the time i got to cyl 4, battery was dying. Im going to recheck tomorrow morning before i leave for work. But im geting high compression numbers with a dying battery.

Sorry if my wordings are misspelled but im on my phone and its acting up a bit. Andii know what u mean about overlooking stuff or assuming its not the problem or w.e. But ive checked about everything 20times. Im not giving up yet because all i need is for the car to start, and i will be driving, then i can focus on paint!

[L3aN-s13]

Whats the news on this? This is happening to me now. Im thinking it could be the Power transistor.

[drz1ll3st]

A couple things. My gas was old and bad. Running was a link off and my fuel lines to my rail were back wards. If you're condenser reads2.2k ohms then its fine. The pn fro courtesyparts isnt thr right one. Trust me.

[SX APPEAL]

LOL thats a freak combination of problems, but it adds up to a no start. Is it running now?