[dj16bit]

Honda crx can you have spark with a bad ECU?

[TxGreaseMonkey]

No.

[TxGreaseMonkey]

Do you need any help?

[dj16bit]

Hey there,
Thanks for your reply. I am not sure if I have a bad ECU or two Bad ECU's or not getting proper power to the ecu.

When I purchased the car it would not t start, fuel issue . I unpluged the harness and there was no power going to the fuel pump so I ran power to the fuel pump and I was able to start the car. I noticed that the fuel gauge was not working so I asumed that the extra two cables in the fuel pump hardness had something to do with the fuel gauge. I touched the wrong cables while the car was running and it sparked and the car turned off.
Car is not getting spark now. No ignition spark After disconecting the battery terminal for 30 seconds and turning the ignition on, I replaced the main relay with a used one and tried a different ecu,same thing no spark no blinks on the ECU. I checked all fuses, still no ignition spark after disconecting the battery terminal for 30 seconds and turning the ignition on, I replaced the main relay and tried a different ecu,same thing.
I checked all fuses.
I am thinking that I may still need an ECU?

Thanks,
16bit

[TxGreaseMonkey]

Answer these 3 basic diagnostic questions for me:

1. When you turn the ignition switch to ON (not START), does the Check Engine Light (CEL) come on and then go off after 2 seconds?

2. When the CEL goes out, do you hear (or feel) the main relay "click"?

3. During the 2 second interval that the CEL is on, do you hear the fuel pump in the gas tank run?

Your answer to each question above:

1.

2.

3.

[dj16bit]

Answer these 3 basic diagnostic questions for me:

1. When you turn the ignition switch to ON (not START), does the Check Engine Light (CEL) come on and then go off after 2 seconds?

2. When the CEL goes out, do you hear (or feel) the main relay "click"?

3. During the 2 second interval that the CEL is on, do you hear the fuel pump in the gas tank run?

Your answer to each question above:

1.There is an orange light that I believe is the check engine light, It's a [symbol] and it doesn't turn off.

2.The main relay never clicks,I have two used relays neither one clicks. The fuel pump turns on because I temporary rewired it.

3.N/A
__________________

The car did run with the original main relay just the fuel wasn't getting 12v and that's when I ran a 12v cable to the fuel pump and it started. I then noticed that my fuel gauge wasn't working and I taped the two wrong cables at the fuel harness. Does the main relay
Power the ecu in any way?
Thanks again for the help
16bit

[TxGreaseMonkey]

Yes, the main relay provides power to the ECU, fuel pump, and fuel injectors. The Check Engine Light staying on says there's a problem with the main relay, ECU, or ignition switch. Most Hondas will not run, if the CEL stays on. The ECU is signaling the CEL that the system doesn't check out.

First, check all under-dash and under-hood fuses with a test light or multimeter. Pay particular attention to the ACG (S) fuse in the under-dash fuse/relay box. It's a 15 A fuse controlling power to the main relay. It may be Fuse #24, but should be identified on the fuse box cover. Second, turn the ignition ON and verify you have approx. 12.5 v going to main relay connector Terminal 5. Third, replace the main relay with a new one. Fourth, decide whether you need to change the wiring to the fuel pump, turn the ignition ON and see if the CEL comes on for 2 seconds and then goes off. Also, listen to see if the fuel pump runs during this 2 second period. Fifth, if everything checks out, try and start the car.

[badpenny]

I might have the simple solution to your problem. I found this out with my 87 Si. There are 4 different distributor caps for these cars. And depending on where you purchase your distributor cap, you could have the one that the screw holes are not lined up properly, (adversely causing your wiring to the plugs to be off)

[Razi3L]

[QUOTE=txgreasemonkey]Answer these 3 basic diagnostic questions for me:

1. When you turn the ignition switch to ON (not START), does the Check Engine Light (CEL) come on and then go off after 2 seconds?

2. When the CEL goes out, do you hear (or feel) the main relay "click"?

3. During the 2 second interval that the CEL is on, do you hear the fuel pump in the gas tank run?

Your answer to each question above:

1. No

2. No

3. No

[TxGreaseMonkey]

Razi3L, does your CEL stay on all the time? If it does, check your under-dash and under-hood fuses with a multimeter; then, run the K-Test on your ECM.

Read this:

https://www.askmehelpdesk.com/cars-t...tml#post219451

[Razi3L]

Thanks txgreasemonkey I'm going to try this out asap.. and yes the light stays on all the time now because I have grounded out the green black wire from the main really... I wasn't getting the initial click at my relay so I started checking out my my main relay with my test light and came to find out that when I tested the green/black wire it clicked so I figured id ground it out but I'm still not getting any spark. So I'm guessin that my ecu is bad because I'm not getting a ground from the ecu. Also I sent my distributor to the people I bought it from thinking that my ignitor was bad but as so as I get it back I will do the k-test.. thanks for everything

[TxGreaseMonkey]

To perform the K-Test, you won't need your distributor.

[Razi3L]

LoL txgreasemonkey when I went to do the k-test and ground out on the thermostat housing I found my ground loose! Thanks for everything though tx if the k-test hadn't said used the thermostat housing as a ground I would probably never would have found it, because its under other wires and I couldn't even see it.. thanks a lot though txgreasemonkey you are AWESOME!

[TxGreaseMonkey]

That's great news! Remember, keep that Civic going for a long time.

[Razi3L]

dj16bit I was having that same problem.. but what I came to find out was that my ecu ground was loose. You can locate the ecu ground on the thermostat housing. And the only way I found it was because of a step I was following in the k-test.