Hi everybody...I have a 93 civic ex that wont start the car cranks but wont start. Ok when i put the key in the "on position" the pump doesnt prime and none of my dash lights light up(CEL Srs etc..)so i replaced the fuel pump it still doesnt prime. So i check my fuses with a multimeter and everything was fine. Im not getting spark so im thinking its the Dizzy but B4 i replace it will a bad dizzy cause my CEL and SRS lights not to light up when key is in "on position".I then took the fuel pump relay out of my working cx and nothing. I installed the relay from the ex into the cx and it started right up so the relay is fine. I just did a K-test to see if my ecu was bad that another site mentioned to do and i was supposed to read 5 volts from the MAP sensor plug and i recieved nothing. i wasnt sure if i did it right so i check my cx and i read 5 volts. so i figured my ecu was done so i removed the ecu outta my cx thinking it will at least start the car but not run it well and nothing the CEL SRS light still didnt light up...im gonna use my friends P28 in a few days to see if it works hope u guys can help me B4 i can get the ECU

Wondering if you guys can help...

 

check for spark and fuel. then check yuor dizzy wires spark plugs. its a good start.

 

make sure your fuel pump is grounded and that your power wire is "hot". also check the fuel pump relay/fuse and make sure those are good still.

 

I don't know anything about this "K-test" so i can't comment on that, but i'm getting the impression that 1) no Spark, 2) no Fuel? 3) bad signal value. All this leads to electrical unless i'm missing something.

Make sure to check your vehicle schematic before fronting $$ for parts you do not need, if you haven't already. Make sure to check all the applicable fuses including the engine bay fuses and interior driver-side fuse box.

Make sure the MAP plug is receiving power so that it could send a signal out. If it has no input in, it can't send an output to your ecu. Also, some vehicles have more than one relay in the control circuit powering the fuel pump, so check your electrical schematic in your manual (assuming you have one).

It is also plausible, especially in colder climates, to have damage within the distributor. (i.e. i had a vehicle fail to produce spark from a distributor that i had replaced not 3000 miles previous. The diagnosis and solution...one of the ignitor pins broke loose due to thermal stress change between the cold startups and running temperature conditions. The distributor that i replaced my OEM with was not designed for moderately cold conditions (i.e. 0 degrees F)).

Hope that helps. Questions, additions, corrections welcome.

 

thanks guys for the replies.
@Gumbey i have no spark or fuel and i replaced my plugs and wires and still nothing...

@93egsleeper im gonna check the fuel pump ground and see if the power wire is hot. the relay and the fuses are still good...

@Simkin314 the k-test is supposed to check if ur map sensor is getting power..the site said its should read 5 volts if it doesnt ur ECU i bad...and my MAP is not receiving power

does anybod know if the ecu in 92 cx i thinks its a p05 will start my 93 ex?

 

just to save you alot of guessing and other purchases, fix your CEL light first. the bulb simply just be blown

but if you want to make another shot at it, i would check your ecu as well

 

To test it, i'm sure it'll work to start up the vehicle...but I would be concerned about what caused the problem with your car before chancing to burn up another ecu.

Did you switch fuel injectors with low impedance injectors without a resistor box or conversion of any sort...that could burn up your fuel control circuit in the ecu, possibly causing cascading damage along the way.

I don't know, but be careful. It may be beneficial to check whatever ecu pins you can for appropriate levels before throwing another ecu in the mix. ECUs don't traditionally 'go bad' even if it is 16 years old with 300,000 miles.

Your definitely on the right track though, good luck.

 

okay did any of ur indicator lites ever work before this? because they should come on (SRS & CEL) as a pre-test with the key in the on position (2 clicks) and if anything since u have a multimeter measure ur battery voltage (should be 12.6 volts or higher).

 

ive got the same problem.. dropped my turbo y7 engine in hooked everything up ran my resistor box for my injectors thought main relay also. swapped that. still nothing. nothing coming from ecu swapped it with 2 others still nothing. im confused.

 

Wondering if someone figured out a solution. I have the same issue in my 95 cx. After a rain, the cel didn't come on but the car started. Few hours later the same day, the car stalled out and won't start back up. The cel still doesn't come on so I can't read the codes

 

The CEL bulb may be burned out.

 

Check your engine grounds....one on the thermostat housing, one on the valve cover, and the one on the transmission. Check continuity across all those back to negative terminal.

 

it's not that because the fuel pump won't prime anymore either. as if no signal from the ecu

 

You mentioned that before the no-start, the CEL stopped working, so the bulb may be blown.

With respect to the no-start, check dash fuse 25 and hood fuse 31, if you don't hear the fuel pump prime.

 

It ended up being a loose ground on the thermostat housing. Thanks

 

You are welcome!