wutangben

I am having a problem with my car that I need help with. I am going to try to explain it as best as I can, hopefully without making it too confusing. So here it goes...

My car (s13 coupe w/ s13 blacktop) was running fine for a while before I ran into a problem where my car would sputter/misfire/backfire under a high load. It would mainly only happen when I had my boost turned up and I was flooring it. It really sounded like the spark was being cut, (or it just wasn't sparking) and it would pop, backfire, and run like shit... It would be fine if I ran at 7psi, but if I ran at like 12 or 14, whenever I would be boosting, it would be doing the same thing.

I ended up figuring out that my battery terminals/posts were not making a good contact. I cleaned them all, and actually stuck a small nail inbetween the terminal and negative post of the battery to keep the battery cable on there really tight. This actually fixed my problem, and my car ran fine for a while. Then all of the sudden I had the problem again. This time I realized that my positive cable was kind of loose, so i cleaned it up, and used a small nail to keep that connection tight as well, and once again my problem was fixed.

The car ran fine until I did my fmic install.

Now the only thing that changed when I did the fmic install was that I moved the battery to the back... My battery posts/terminals are all clean, but I would have that sputtering/backfiring problem whenever I'd be flooring it during high boost. It isn't really a consistant thing either, it would do it randomly. Sometimes it would backfire a lot really loud, other times it would just backfire a few times through the revs and just cause it to not accellerate smoothly. I could drive the car at 7psi, and about 75% of the time, I can drive the car at 10psi without it doing it. Anything more than 10psi would cause it do have the same problem.

Since I'm pretty convinced that this is an electrical issue, I went ahead and cleaned up all of my grounds. I took a dremmel to all the surfaces, and all of the connectors and everything. I thought this would fix my problem, but I took the car on a few short trips and it still happened. Then all of the sudden my car ran fine. I could run at 14psi, no problems whatsoever. It ran good for about 100 miles before it started doing it again. I thought maybe the battery just needed a good charge from the alternator, and that's why it didn't fix my problem right away, but unfortunately it the problem came back, and it's still here!


I can't figure out what the heck it could be. The only thing I changed was that I moved the battery into the back. The only other thing aside from that that I can think of is that the hose going from my cold pipe to my intake manifold is a little bit twisted/kinked now. I can't think of anything else...

Anyone have any ideas? I just want my car running right again!

Ben

wutangben

If someone figures this out and gets my car running right, they'll have an extra $20 in their paypal account.

the head

1. do you have a large (1,2,or 0 gauge) ground in the back?
2. are all of your ground straps in good condition (no tears or corrosion)
3. Did you also run a ground up to connect with the grounds in the front of the car (I hooked mine into the hyper ground system i have mounted to firewall)
I am sure this has to do with a grounding issue

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I never knew you could do that with an eggplant

wutangben

1. I have a large ground in back, not sure what gauge wire it is, but it's whatever wire comes with the battery relocation kit that summit racing sells.

2. The ground in back is clean obviously since it is new. The ground on the left side of the motor that goes to the battery base tray, or whatever it is, is nice and clean. And the small ground at the back of the engine is fine if I remember correctly. The one cable that was kind of crappy/corroded was the positive to my alternator. I cleaned up the cable though, brushed off the corrosion, and taped it up...

3. I am not sure exactly what you mean by did I run a ground up to connect to the ones in the front of the car. Do you mean the grounds by each of the headlights? What exactly are you asking if I did? I haven't touched those...

the head

I used an HKS central ground in the engine bay then ran battery grounds to it as well
try replacing the ground straps with some 8 gauge wire also I may be wrong on this but arnt there more than two grounding straps for the engine?

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I never knew you could do that with an eggplant

wutangben

I don't think there are more than 2 engine grounds... I'm looking at those HKS-Style grounding kits on eBay, are they worth it?

the head

I had the same problems you had and it cleared my issues up

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I never knew you could do that with an eggplant

420sx

go pull out your spart plugs and gap them all to .30

do it now! also check ur coilpacks

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hydropgrahics!
ls1......