the car: 97 civic dx
engine: 97 jdm gsr

I was driving last night and did a pretty hard pull approaching 90mph in 3rd gear then let off the gas. Put the tranny back to 4th and then the car just died. Had it towed. I replaced the dizzy and fuel pump thinking that would fix it. But I found the FI E/M fuse was blown. I replaced it with a 15a fuse. Drove it down the street, then it blew again. I put in a 20a fuse and drove for a while, it ended up blowing. So I put in another 20a fuse but it instantly blew with the ignition on the first position. Ideas anyone?

 

bad wire

 

First, never install a higher than recommended amperage-rated fuse as you risk frying the circuit and causing a fire.

The blown fuse is 15A fuse 44 under the hood, right?

Obviously, you have an electrical short. To pinpoint the short, unplug components one at a time on the circuit to see which disconnected component does or does not prevent the fuse from blowing. You may need to buy a box of 15A fuses for these tests. Start by inspecting the fuse slot itself. Do you see any signs of burning or damage? If not, proceed with the test below.

Unplug the the connector for the components below in the order. Stop the test when you find the first disconnected component that does NOT prevent the fuse from blowing, even if it is the first component on the list. Post your findings.

1) main relay
2) all four fuel injectors
3) IACV
4) ECU connector A

 

Thanks I'll give that a shot!

 

Okay, so here are more things I've found. With nothing plugged in (no fuel pump, injectors, ecu, and main relay) the fuse pops when turning the ignition to the 2nd position. More ideas?

 

Your test results say that the short is located in the Wht/Blk wire running between the hood fuse box and the main relay or in the fuse box itself.

The next step is to disconnect the battery, and remove and unplug the hood fuse box. Then use a multimeter to test for a short in the Wht/Blk wire and also inspect the rear of the fuse box for signs of a short. If the Wht/Blk wire does NOT have a short, then replacing the hood fuse box should solve the problem.

 

New observation. I plugged everything in. except for the main relay. The fuse DOES NOT blow. I plugged in with a new main relay, as soon as ignition hits position 2, the fuse DOES blow. I tried with 2 different main relays. I gotta get this fixed!

 

Okay, that's a different result. Now unplug everything except the main relay. Does the fuse still blow?

 

Without the main relay, nothing blows. It's only when the main relay is connected. In an attempt to educate myself, I stumbled across this:

http://www.tegger.com/hondafaq/mainr...ion/index.html

When testing the terminals on the main relay while connected, I'm showing ground on connections 3, and 6 when ignition on 2. I'm not too great as an electrician So I don't know if that's good or bad and how it relates to that diagram in the link above. This is so frustrating!

 

Do this^, and post the results. Otherwise there's not much more to discuss, because you will be randomly guessing what the problem is.

 

I did that. The fuse does NOT blow. it only happens when the main relay is connected. I've tried 2 different relays all with same results.

 

So if EVERYTHING is unplugged EXCEPT the main relay, the fuse still blows? Where did you say that you tested this?

 

Yes, it blows with nothing else connected except for the relay and the ignition on position 2. I'm at a friends house where my car is. he's knowledgeable of electronics and circuits but even he's stumped as we've tried to isolate the problem. Any other ideas?

 

I have lots of ideas, but I need solid facts to help you. Originally you stated that the fuse blows with everything disconnected, including the main relay. You now say that the fuse blows with only the main relay is connected. Are you absolutely sure the latter is now correct? I'm asking because I don't want to take time developing new troubleshooting for a false lead.

 

Sorry to have confuse you. Yes, the fuse blows even when the relay is the only thing connected and the ignition is on position 2. If ignition is on 1, it doesn't blow, only when on 2.

 

And, under these same conditions, if you now unplug the main relay, fuse 44 will NOT blow, right?

Do you have a digital multimeter and know how to test for an electrical short (continuity to body ground?)?

 

yes, we do have a volt meter which has been helpful to us. not sure which pins to test on the relay.

 

A voltmeter can't test for shorts. You need a digital multimeter that allows you measure resistance/continuity (Ohms). Can you get one?

 

Yes we have one.

 

Okay, give me a couple of minutes, and I'll post specific terminals of the main relay connector to test for shorts (continuity [~0 ohms] to ground) when EVERYTHING is disconnected (main relay, ECU, all fuel connectors, and IACV).

Main relay wire harness connector:

 

Okay, test for continuity to ground on terminal 6 of the main relay wire harness connector under the conditions I mentioned in my previous post. Use the under dash metal frame as ground for this test. Set the multimeter to the lowest/smallest Ohm scale for this test and post the Ohm reading and Ohm scale used.

 

Will do! What is pin 4 and what is it's function? My friend has a feeling this may be the culprit.

 

Pin 6 IS grounded.

 

Pin 4 leads directly to the fuel pump and cannot be the cause of the short, based on the circuit diagram.

 

Pin 4 is not showing 12v at all in any ignition position. pin 6 is shorted to ground. is this correct?