Blowing FI E/M Fuses! Please help!
#1
Blowing FI E/M Fuses! Please help!
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?
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?
#3
Re: Blowing FI E/M Fuses! Please help!
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
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
#6
Re: Blowing FI E/M Fuses! Please help!
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.
#7
Re: Blowing FI E/M Fuses! Please help!
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.
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.
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#9
Re: Blowing FI E/M Fuses! Please help!
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!
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!
Last edited by zerovandez; 09-06-2009 at 04:02 PM.
#10
#13
Re: Blowing FI E/M Fuses! Please help!
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?
#14
Re: Blowing FI E/M Fuses! Please help!
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.
#16
Re: Blowing FI E/M Fuses! Please help!
Do you have a digital multimeter and know how to test for an electrical short (continuity to body ground?)?
#18
Re: Blowing FI E/M Fuses! Please help!
#20
Re: Blowing FI E/M Fuses! Please help!
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:
Main relay wire harness connector:
#21
Re: Blowing FI E/M Fuses! Please help!
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.
Last edited by Former User; 09-07-2009 at 09:27 AM.
#24