[pantaloons]

My 99 LS has recently begun to stumble or stutter at low rpms in mainly 1st and 2nd gear.

I am thinking this is somehow nitrous related as I've had a zex kit spraying a 65 shot for about a month.

Any ideas?

 

[JustinKlemgold]

Oy....nitrous is never a good thing for your engine but I don't think it's that. It may be your spark plugs...have you checked them? Have you changed them since putting the nitrous on? I think it was on here that someone said that it's a good idea to go to different spark plugs when using nitrous...perhaps a colder plug or something? Someone can correct me if I'm wrong...

 

[JustinKlemgold]

Orrrr, you never mentioned what kind of tranny you have...I believe it is adam57xx that had a nitrous setup in his car similar to yours and he was on an auto tranny and now he is experiencing tranny problems....if you're a manual then disregard what I just said, unless you haven't upgraded your clutch...dang, it could be a few things...

 

[pantaloons]

I have a 5spd.
When I installed my nitrous I put in new NGK bkr7e plugs that are supposedly the best to use w/ nitrous.
I'll check them anyway.

 

[MichaelDelaney]

if it stumbles off the line you have too much cam for your engine or the ignition timing is delayed too much for it. Advance the intake cam. You really can't do too much on the ignition timing except to advance only on the lower rpms using a programmer like a Hondata or AEM EMS or Apex Power FC or you can use an igniion specific controller like the Apex ITC or Shogun Power Tuner. The nitrous dictates that you don't advance the base timing at the distributor.



If it dies up top, you are getting too much reversion or too much burnt gases staying in the chamber. Pretty basic stuff. Advance the exhaust cam. The Zex electronic fuel box may have something to do with the upper rpm stuff but I doubt that it's affecting your low rpm problems.

 

[JustinKlemgold]

clutch? What about your clutch?

 

[JustinKlemgold]

What MD said was going to be my next guess

 

[pantaloons]

It's a stock clutch but only has 40k on it and it.

 

[JustinKlemgold]

Adding a 70 shot of nitrous is going to wear your clutch out a lot more quickly is it not? I don't really know about nitrous, but I do know that when you go turbo (turbo adds about 70HP too, at a modest PSI) you have to upgrade your clutch because that type of stress eats up a stock clutch. I hope thats not it and it's just what MD said....clutches are expensive...

 

[FlyinHighImport]

Mike D you are a god in the automotive knowledge...anywhooo whatever mike and justin said is probably right.

 

[MichaelDelaney]

do me a favor and check your plugs. make sure you haven't burnt one. Check the gaps and make sure you gap them properly. A messed up plug that has fouled or has been eaten by detonation will cause misfiring and stumbling as well.