andrewvong

Hey Honda-tech, I want to give a quick introduction that I am a new member as I finally registered an account.
I have been on these forums many times to find problems that I had to my Honda and reading the forums
here solved so many problems. Even gave me the motivation to do my own build. So now I am finally stuck
somewhere and can't find the problem.

So this is my first project car. EG civic hatchback with a b20z1 block and a gsr head. I did the whole build
myself except when I shipped my block to golden eagle to get it ported and my head also ported somewhere
else. After putting everything back together and mounting back into the engine bay it was time to start up.

The first time I turned the key all the lights on the dash was on, everything was working so far. After turning the
key to make it turn over nothing happen but the fan started spinning. Stopped there to check the web to see what I
need to check. (fan stopped spinning after awhile)

The next time I worked on the car. I tried to test the car if it would turn over this time but instead it completely turns
off with no power to the dash lights nothing worked. Gave up and went to to do more research.

This time I decided to clean all the grounds and positive wires, check all fuses with a light tester. Cleaned the one on the starter, thermostat housing
and the negative battery wire. When I went to start it all lights came back on and the car was cranking, I cranked it
about 2 seconds and decided to stop. I decided to give it a little more battery power so when I plugged it in for
it to charge it, then all the power died again.

So far I did a Voltmeter test and it seems like there is power running through the engine bay. The plastic piece for the clutch is
still there for the bypass, and my ignition switch still works since there is power running through there too from checking the two
plugs under the dash. But still no lights to the dash and nothing turns on when I turn the key.

Last mistake I found out recently was my ECU was smoking and I think that was due to having the MAP sensor not plugged in.

This is so far what I have found out and tried to do, if anyone has any suggestion to help me solve this mystery that would be awesome.
its been 3 months since I been trying to figure this out. Need all the help I can get.

Thank You.

2LEM1

iTrader: (1)

Hey, at least it wasn't vaping.




You need to take this car to someone that knows what they are doing.

andrewvong

yeah, that would have been bad.

Probably, I didn't want to as I want to do everything myself but it seems that would be my last option
if there aren't any options left to do.

Thanks for the reply.

2LEM1

iTrader: (1)

Where are you located?

mk378

Smoke from the ECU is really bad. Merely having a sensor unplugged will not do that.

The ECU grounds on the thermostat are easy to forget when swapping engine.

Saying "there's power running through the engine bay" is not very specific. First I'd look to make sure the battery isn't connected backwards. Then check each connection and ground with a voltmeter. Turn the headlights on (key off), if they don't come on though the battery is charged, you have a rather fundamental problem.

andrewvong

I am located in Rhode Island.

andrewvong

Can the ECU grounds go bad in any way?

Okay, maybe I can get some pictures in to help. ill try and do another voltmeter test and check my grounds again.

m90polk1

Sounds like you have power and ground, even though you may have continuity it doesn't mean the car will start. Under cranking conditions all other electronics turn off because of the amperage needed to spin the starter and crank the motor. You need to make sure your engine grounds to chassis are sanded clean because the starter uses the transmission as ground. There should be a ground from transmission to passenger side frame rail. Make sure that wire is thick enough like 0-8 gauge, and is not corroded. Where are you in RI, im in Providence?

andrewvong

Thanks for the reply! Sorry been busy because its almost Christmas, haven't had the time to take pictures and work on my civic
also that it is super cold out now. Yeah I sanded the chassis and the transmission ground. I bought a 4 gauge new ground cable
since the old one was ripping a bit. should I go bigger than 4 gauge?

m90polk1

That should be fine

fcm

No power at all is defiantly a connection problem, either power or ground, [ground being the most common] T would recheck/do the main grounds, batt. post and cable clamp. batt. to chassis ground and chassis to engine ground, a simple 12V test light, [not LED type] is all you need to confirm engine and chassis grounds, connect test light ground terminal to batt neg. post, touch test light probe to any part of engine, [test light should light up] then have someone turn ign. key to run, [test light should still be on, then have them turn key to start, [even if engine does not crank, test light should still be on] if test light goes out you have a grounding issue, do the same tests with test probe to chassis, [shock tower bolts will work great], same tests if at any point the test light goes out or even dims there is a grounding problem.

If you confirm the grounds at good then start checking the power connections, batt. to under hood fuse box, and main fuses.

Loosing a ground to the ECU can be very bad as power will "look" for a ground, remember electricity takes the cores of least resistance, in a DC circuit if a ground for a circuit is not available it will look for one and that can be though circuits that can not handle the current resulting in "smoke", as that circuit blows like a fuse, it may be a capacitor or resistor or other component, or even just a circuit trace on a circuit board in the ECU, open the ECU if there was smoke the burn should be easy to spot.

Before replacing the ECU you need to solve your other problems first. or it will/may happen again. 94