Hello ppl !! Really dont post too much here but im always reading a lot of good info and following a couple of interesting builds here.
But straight to the point , Have a 96 civic HB DX with a lsv turbo. Built. Using the s300. Have a basemap on the ecu. And for some reason sometimes when i turn the car on has a solid CEL , wont let me connect to the ecu to troubleshoot or not even giving me the code(blinking CEL ) by jumping the blue plug. Now if i turn the car off and just open ign. No cranking until the main relay clicks when that happens the cel goes out. Kinda resetting it.and the car starts and runs like a champ , But sometimes i do the same and get the Steady CEL back on.

Could it be the ecu going bad , main relay ?
Not an expert , trying to get some input.
One other thing i noticed that is happening. My ignition switch gives me a hard time to turn to unlock the steering wheel .. Will it be correlated ??


Thanks in advance !!

 

Next time this happens, leave the switch in ACC with the solid check engine light. Wait 5-10mins to see if the pump suddenly primes and the light goes off. Then start the car. We are troubleshooting the ECU - get back to me...

 

The pump primes and all that ! It just stays solid until i switch on and off for 2 or 1 time sometimes

Thks

 

Bump ! Anybody ??

 

if the pump primes, main relay is fine. if the pump does not prime, main relay is probably bad.
if the pump primes, but the cel stays solid, its more than likely a fault with the ecu.

what happens when you jump the service connector? does the cel stay lit? does the cel go out and stay out without flashing anything?

have you tried unplugging the ecu for several minutes and then plugging it back in?

have you checked/cleaned/tightened all your grounds? specifically the main signal ground on the engine from the harness

 

When i jump the connector. It stays lit nothin happens , and the ecu wont connect
When that happens i just turn off ignition and back on.

Checked pretty much every single wire but will check again ! Thks

 

Are your injectors getting power when your CEL stays on?

 

Start by trying the ECU in a known working Vehicle. If the problem goes away you know it is specific to your car. If the problem follows the ECU then it is possibly a damaged or dying ECU.

 

So i tried the ecu on another car same problem. Swap s300 modules to another known workin S300 ready ecu. And boom. Everythin back to normal. So the S300 was good. Just a bad ECU. Problem solved. Thanks to those that put their 2 cents in.
Thks.