Hey guys, Just fired up the rebuild today, fired up pretty much right away, tonnes of smoke but after 10 minutes i have her idling at 1000, and a nice even exhaust note, starts up right away also with used housings and new apexs. Anyways, when first trying to get her started up, my friend noticed that my exhaust tips were arcing electricical sparks against the reat metal part of the lower bumper, I bent the metal part up so it wasn't near the exhaust and it stopped, but what would cause this, I did recently put the battery in the trunk, but it wouldn't explain the sparks? There aren't any shorts, and everything else works fine, the exhaust also only arcs when cranking the engine. What gives guys, its got me scratching my head. On a side note its so nice to hear that sweet rotary exhaust note after 7 months.

Thanks, Matt

 

awsome so you did the rebuild yourself
so what parts did you replace just the apex and new gaskets or did you buy a rebuild kit etc
gimme some details

ohh i would have clue bout the spark sounds out of it

btw congrates on a happy day

 

you know theres a ground on the stock muffler? i only found it when it fell off when I pulled mine out, lol

 

That's a new one on me. My first thought is you need better grounds somewhere and check the positive battery leads for any leakage/shorts. Traceing this one down might be a headache.

Congrats on the first fire up.

 

nm. they beat me with the ground wire.

 

I noticed that on Sec gen cars(may not Pertain to you..but here goes anyways)..That on mine ther was a ground strap that attches to the Exhaust and goes to the Frame.When I replaced the clutch I removed/replaced the exhaustI replaced the strap with a new one...Maybe if you Attach a Ground Strap that would fix the "odd arcing thing " goin on with you .Not a Clue,why it is Arcing either ,but it seems like maybe The strap was there for A Purpose?..For What I'm nOt sure.maybe some-one else Knows?..would be informative.LUck to ya Matty..DAVE/MrSTYX

 

I figured the entire exhaust would be grounded already since its bolted to the engine and its fully welded togeather? Also any clue to why it would only happen during cranking? My friend also said that the sparks were pretty thick and orange. for the rebuild i used the best parts out of 3 blown engines, and replace one of the housings with a used housing from ebay. IT was a great day yesterday, I replaced all seals except for the side seals and corner seals, and i replaced all springs, and Ported the engine myself using the racingbeat templates. a little starting fluid and she was growling back to life, I'll never forget it.

 

I would say it is a bad ground to the starter.

 

I would think that the only way that could happen is if there is a bad ground to the engine, since the starter is bolted right to it. Worth checking it though. I'd check the ground wire that runs from the battery to the frame and then to the engine just above the starter, as well as the ground strap on the rear of the exhaust...it connects to the rear muffler bracket .

Rich

 

The engine ground is the one that goes to the starter bolt on the engine. Other then that the engine is not grounded to the car. All the other connection points have rubber in them.

 

Hmmm...on mine the ground is on a transmission-to-engine bolt just above the starter, but not one of the starter bolts (I think). Not much difference, just has me curious now. I'll try to remember to check tonight.

Rich

 

my guess is the starter is shorting to ground. It's closest ground is the tranny > engine > exhaust > arcing you see at muffler.

try another starter, they're not expensive. even a junk yard one would be worth a try.

I'd also add a ground cable from engine to frame. Run it from a front cover bolt to the frame where battery goes. 2 gauge or thicker. Add another where muffler goes. That helped my voltage and battery charging too.

 

A starter shorting to ground would not cause arcing at the end of the exhaust system. It would cause...well, at best it would cause a dead battery and a failure to turn over the engine, and at worst it would cause an exploding battery.

I really think that if the ground strap were connected to the tailpipe like it's supposed to be all would be good. I'm surprised that the arcing is as bad as it sounds like it is, but there's a reason they put a ground strap there.

Rich

 

What if it's just static buildup? Like 64mgb said, it has a ground strap back there for a reason.

Congrats on getting it to run. I had a similar experience with a certain white GSL a few weeks ago.

 

Lucky you

but odd situation...

 

On mine the Ground has been on the engine side of the long bolt for the starter, The one that goes in from the engine side.

The exeaust is grounded to the engine and then the engine to the batt thrugh that one cable, So the one at the muffler should not really be needed.

 

How about this. The muffler is just held on by rubber things. If and when they fail, the strap is there to keep the muffler from dragging on the ground.

 

That is what the peice of chain run under and welded to the muffler is for.

 

There are 2 engine grounds. The battery cable and another one from the top of the engine to the firewall.

Odd, I have never noticed a ground strap on the exhaust/muffler.

 

The engine has inadequate grouding. you are correct that the exhaust system is grounded through the engine, so the only way that it would be sparking is if the engine did not have a good clean ground. Should be simple enough to check, just run another wire across from the motor to the - on the battery and see if it goes away...

 

Yea the grounds we an issue, it stopped arcing after its initial start up. I checked my plugs inbetween initial crankings and found that the were stuffed with vasoline. If this were the case, and i had poor engine grounding, i'd guess that all the enegry from the coils would just be ground to the engine, and then cause there were no good grounds, it would have made its way to the muffler, and then to the bumper to ground out. Its pretty screwed up, but makes sence. I added a 2 Gauge Ground strap to the top of the engine, and it runs much smoother. I Forgot to add any grounding to the engine after the install.

Thanks for your help guys

 

Good to hear you got her fixed man. I read a post by someone who was burning up throttle cables due to an engine grounding issue. That cable was the easiest route for the juice to take, but the cable couldn't take the heat. He went through a few of them before he figured it out...

 

The bad grounding could also explain the heated wire from the alternator that we encountered.