Background info.
I bought a 90 Civic Si shell a while back. The guy bought it from bought it from someone else. And doesn't know if the car ever ran. The A6 that was in there had spun a bearing and had high mileage. So I replaced it with a complete OBD0 B16 swap that I bought from a local forum member. While doing the swap I wire tucked the engine bay. I soldered and heat shrunk all the wires I cut. I also relocated the battery to the trunk.

The problem.
When I turn the key to start the car. It would turn over like half a turn, click then everything dies. The door chime stops chiming, cluster no longer lights up no mater what position the key is in. When I disconnect the battery and connect it again everything lights up as normal until I turn the key again.

Any help would be greatly appreciated, thanks.

 

Negative battery terminal is loose on battery or isn't grounded it h
appens to me a lot

 

x2.

 

x3

 

x4

 

Thanks for the tip but still nothing. I ran the power wire back to the engine bay. I connected the stock grounds that go to the valve cover and the one to the tranny and still wont start. Although now everything doesn't die. The engine just turns a little bit then a lot of clicking. I also took off the starter and gave it direct power from the battery and it works fine. The motor isn't locked either, I can turn it with a ratchet at the crank. The battery is good and so are the grounds. I'm thinking it could be the power wire going to the starter. I'm going to try to put a larger power wire to the starter tomorrow if I have time. Anyone else ever have this problem? Again thanks for the tip.

 

check all grounds. The ground on the main harness has to be on the block/thermostat housing. If that fails go over all your wire tuck with a continuity tester and see if you dont have a short.

 

As everyone else in the thread has stated thus far, IT'S YOUR GROUNDS!!!

But on a side note, what size wire did you run for your battery relocation? Nothing smaller than 4AWG I hope.

 

check your ignition switch, my car was doing the same and it was the ignition was losing power after the key turned

 

The car started!!! Then my ECU fired...

I checked all my grounds again and still nothing. The power wire I had running to the starter was the old alternator wire. The wire I used for the actual battery I'm not sure on the gauge. It's pretty thick, it's about as wide as a penny maybe bigger.

I ran the power wire from the battery directly to the starter. I also ran the power wire to the fuse box to the starter. So the starter was the distribution block I guess.

The car started right up on the second try. I was so happy. I let the car Idle to get to temp. I revved it a few times to hear the loudness of the open header. It's was loud. Within ten minutes of the car being on it died while idling. I go to start the car again when I smell something burning. I look to my ecu and its smoking. I unplug the ECU and start cursing up a storm as I open her up to see this:



It looks like the capacitor tried to launch off and took a spray **** all over the board. lol


My question now is, what caused this? Where should I start looking for a short or was it a faulty ECU (doubt it)? I'm all ears.

 

Should I start another thread?

 

probably no need unless you have an issue with getting help through this one.

i personally have never seen or heard of what happened to your ecu happening before. If it were a mis-wiring issue i would think the ecu would have fried before ten minutes passing.. so maybe there was some odd internal issue with the ecu. I woudn't blame you if you were worried to plug in another ecu though lol.

 

Yeah, I don't want another paper weight. It wasn't exactly 10min it was more like 7 or 8. Either way when I was revving it in the car I didn't smell the burning ECU just the exhaust from the open headers.

 

The difficulty starting and the short circuit may or may not be related. It is impossible to say because the car ran...... until either one of two things happened.

1. ECU shorted internally
2. Wiring shorted. (I have seen "sharp" solder peaks that poke through heat shrink)


Check if any wires in the harness also got hot or show signs of beginning to melt? it may give you a clue which circuit is bad. Recheck wiring for continuity to the appropriate sensor location etc. Then Recheck all wiring for continuity to ground. Then recheck wiring for continuity with each other. It's long tedious work but very straight forward and not difficult. If everything checks out, get a new ECU and hope for the best.

 

Thanks for pointing me in a direction. Looks like I'm going to be busy for a while.

 

I didn't get to check out the car today. I did however do some research. I think the capacitor did take a **** on my ECU. These ECU's are at least 16yrs old and the caps wear out and leak or pop.

This guy even includes the capacitor that exploded on mine in his chipping kit.
http://cgi.ebay.com/ebaymotors/civic...mZ280546735240

On his pics the burnt ecu looks a lot like mine which leads me to believe that the capacitor was the cause of my fried ECU. I'll still look for shorts but now I'm not that scared to plug another ECU

 

are you still running obd0? i have a pw0 sitting around somewhere...

 

She runs again!!!

I didn't get a chance to go over the wiring. Instead I bought another ECU and swapped out the chipping parts, plugged her in and viola! Starts on the first try.

I kept the covers off the ECU and kept touching it to see if it got warm. To my surprise it didn't, it was as cool as a cucumber. The car didn't get to temp, but it was late and the car was loud so I called it a night. Even tho it didn't get to temp it was on longer than the previous time with no burning ECU. Tomorrow I'll make sure everything checks out and hopefully put the car back on the road.

HELPFUL ADVICE:
If your OBD1 ECU has never had the C14 capacitor replaced, it would behoove you to do so. When it fails, your ECU is effd. Failing capacitors smell like bad fish, nasty pu$$y. Its a different smell than burning electronics. They also leak out a liquid called electrolyte. So if your ECU is old (more than likely it is) REPLACE THE CAPACITOR or end up with this: