mods are in my sig.


for awile my car has sputtered from like 4k-6.5k at WOT (***only when warmed up...never when cold***). Spraying the sputtering is even worse....any ideas on where to begin.

 

i would check the basics first like plugs and wire's then the opti sounds like the problem i got and i'm pretty sure its the opti

 

Fuel pump maybe? Get that checked out.

 

true it could be your fuel pump, check fuel pressure

 

So it only does it during closed loop?

 

I had a similarproblem but my car isn't cammed and my stumble was down in the lower RPM's. What ended up being my problem was that my spark plugs we gapped at a .58 (cold) and when it warmed up I think because of the heat they would expand even further not alowing the spark to jump. Once I corrected all of them I had no more stumble. It would make sense that when you spray it stumbles more because the atmosphere in the cylinder is denser and requires a heavier spark to ignite it. So either you have inadequite spark(opti), or to large of a distance in the gapping of your spark plugs.

Zack S.

 

i have stock gapped tr-6 plugs gapped at .036 i beleive. The opti is brand new, however i used to rev the **** out of my car (7000rpm) but i cant remember if it studdered or not. i think fuel is the problem because when i spray my 125 shot.....it just gets worse. I pulled the plugs and they where white.

but yes...it only acts up after its at normal operating temp.

 

I had a sputtering problem for a while last year that I couldnt figure out. My plugs and wires were brand new too so I thought that couldnt be the problem and overlooked them. Finally found out one of my plug boots was torn and arching against the header. Replaced it and it ran perfect. I would check all your plug wires closely for any tears. I would also recomend checking your fuel pressure to make sure it's not running out at upper rpms.

BTW, how did you go through seven optis? That's got to be a record or something. I'm still on the original, I think if I replaced mine three times or so I would probably have sold the car by now!

 

talking about plugs what should they br gaped at.? i have mine gaped at 50.

 

I think .50 is stock. I did try mine at .35 and it worked but milage was bad due to lack of complete combustion. If you have yours at .36 it should be sparking with no problem. I would open up your hood at night in a completely dark area and look for lightining. Rev it up and look as well. If you wires are ok, you have a brand new opti, and your plugs are gapped right and the porceline isn't cracked then I would try replacing hte fuel filter. Its an easy job.

 

how long since you've changed your fuel filter, inadequate fuel supply (ie filter/pump/regulator/clogged injectors) could definitely cause high rpm stumble but it shouldn't much matter when it's cold I wouldn't think

 

If it runs perfect when cold then bad when it warms up it is probalby a closed loop/open loop problem. Your O2 sensors are not used when the car is cold. If they are bad, they will only cause a problem once it is warmed up. My car did the same thing and new o2's fixed it. It could also be a MAF or other sensor problem.

EDIT:
If the problem is at WOT only, the o2's shouldn't be the problem since they aren't used at WOT.