kaozzsc3/4

I was at the chinese resturant in my black sc300 heading to the strip club with my wifey when i got in the car it wouldn't start engine was cranking but thats about it. Thought it was the timing belt but it's good, distributor is new,all plugs and wires are new,but I am not getting any spark might be a dumb question but I own a sc300 and a sc400 same year can I switch the (ECU) to see if its a coputer problem.any idea on what it can be besides the computer an how can i check.cars been down 2 week now. spent more than $800 on things all good to do but haven't fixed the problem need help!!

5sp_jzz30

iTrader: (2)

ecu is not interchangeable. think about it...one is a 6 and one is an 8. more wires to fire more injectors and ignition to say the least.

check your EFI relay and fuse in the fuse box in the engine bay. make sure you dont have spark. take the wire off the coil and put it close to the chassis while cranking. if you have spark it will arc to the chassis.

to check fuel you can take a multimeter and check the AC voltage on the injectors.

if you have the wiring diagram to your car you can check the wiring from the ecu.

i had an electrical problem before that took me about 2 days to diagnose and fix with the whole interior removed and i had the factory service manual.

what year is your sc300?

kaozzsc3/4

alright I know I dont have spark thats why I replaced all my spark plugs, distributer etc... definitly have gas. Is the wiring diagram in the owners manual? The year of my sc300 is 1993. also how do I check the efi relay and what does it do?

5sp_jzz30

iTrader: (2)

the relay will click and you will hear and feel it when you turn the ignition on. when you pop the hood and open the fuse box look inside the lid for its location. its a small round looking relay with a metal top. at least thats how mine looks in my 93 sc300.

do you hear the fuel pump turning on and priming when you turn the key to the on position.

the wiring is not in the owners manual i believe. its a separate volume on the wiring you have to buy on top of the mechanics one.

one thing you can do is take plug off the coil, the one with two 18ga wires on it, and put a multimeter on it. you should be getting voltage when cranking. if you dont then you might have something related to the ecu.

btw there is also a fuse in the fuse panel in the drivers kick. that fuse controls the power going to the ecu. if that fuse is bad or the wire connection from the ignition cylinder to the fuse box to the ecu is bad then your car will crank all day and wont start.

lexdud

That'l teach you to take your wife to the strip club.

On another note ... what year is your car? If it is a '96 or later get your hands on an OBD II scanner and plug it into the port under the steering wheel. You might come up with something that will help.

Good luck ...

kaozzsc3/4

thanks for the info will try it tomorrow I'm not a mechanic but I love this sc the year is a 1993 and to lexdud we both work in one.

mteele

iTrader: (5)

If you thought that you could swap and SC300 and SC400 ECU...you probably arent experianced enough to be doing any of your own work Take it to a pro, let them figure it out.

Good luck!

kaozzsc3/4

ya ur right and i should probably pay someone to change my tire when i get a flat but wheres the fun in that ? i was 99% sure the (ecu)'s could not be swapped but on ebay they said it works for the 300and the 400 so I knew I could count on someone like you mteele to give me such good advise. once again thanks for the help.

5sp_jzz30

iTrader: (2)

did you completely miss the part where i mentioned what you need to check? if you check all the above mentioned things you WILL find your problem....

kaozzsc3/4

5SP JZZ30 I checked every thing you told me no luck so far looks like its still the computer . I'm not getting power from the computer to the igintor but I did forget the last part about the fuse in the kick panel will check today and get back to you but I think I checked the power going into the computer. I do appreciate the help.

5sp_jzz30

iTrader: (2)

if you dont have power going through that fuse in the drivers kick panel your ECU wont turn on. the ecu turns on all of your EFI related accessories including the ignitor, fuel pump relay and the fuel pump itself.

kaozzsc3/4

hey just got an idea in my head

i took my dash cluster out to send it to lextech about two months ago. i havent even sent it to them yet. could that be affecting my ecu?