My 98 coupe idles horrible! I've already done the checklist of: alignment, balance, break fluid.. what else could it be? It seems like my engine is hesitating, or getting a loss of air flow (RPM's go up & down)..
The engine mods i have are the typical I/H/E
Suspension mods, front & rear lower&upper strut bars, coil overs (2.25" all around) and shocks.

Any ideas on what it could be, or how to fix?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by EJacul8 &raquo;</TD></TR><TR><TD CLASS="quote">My 98 coupe idles horrible! I've already done the checklist of: alignment, balance, break fluid.. what else could it be? It seems like my engine is hesitating, or getting a loss of air flow (RPM's go up & down)..
The engine mods i have are the typical I/H/E
Suspension mods, front & rear lower&upper strut bars, coil overs (2.25" all around) and shocks.

Any ideas on what it could be, or how to fix?</TD></TR></TABLE>

I'm not sure why those three things came up when you were checking idle characteristics...care to explain that to me?

Odds are - without you further describing what your engine is doing - your IACV, FITV or manifold vacuum tubing is damaged, thus causing your idle to be rough and/or jumpy.

I can also tell that you didn't search whatsoever before asking this question. I guarantee there's nothing that your car is doing that someone else's car hasn't done in recent memory. Go search the archives and see if anything comes up and, in the meantime, describe the idle a bit better for us.

 

very true

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Archidictus &raquo;</TD></TR><TR><TD CLASS="quote">I'm not sure why those three things came up when you were checking idle characteristics...care to explain that to me?</TD></TR></TABLE>

thought i read someone posting something about their car shaking bad when idle, and this is what someone told them to check, my bad i guess


<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Archidictus &raquo;</TD></TR><TR><TD CLASS="quote">describe the idle a bit better for us.</TD></TR></TABLE>

well it fluctuates, it will run at normal RPMS (500-600) and not shaking.. then it will drop to close to 0-200 RPMS and the whole cabin will shake, and it will continue to do this until accelerate

 

ideas?

 

IACV needs cleaning. Check your timing belt also

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by i need a new username &raquo;</TD></TR><TR><TD CLASS="quote">ideas?</TD></TR></TABLE>

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Archidictus &raquo;</TD></TR><TR><TD CLASS="quote">
Odds are - without you further describing what your engine is doing - your IACV, FITV or manifold vacuum tubing is damaged, thus causing your idle to be rough and/or jumpy.
</TD></TR></TABLE>

that's your answer right there. First check IACV and FITV. If its not either of those, then buy some carb cleaner and spray it around the intake manifold while the car is running. If the motor bogs you found your leak. More than likely, its IACV or FITV though.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by i need a new username &raquo;</TD></TR><TR><TD CLASS="quote">


well it fluctuates, it will run at normal RPMS (500-600) and not shaking.. then it will drop to close to 0-200 RPMS and the whole cabin will shake, and it will continue to do this until accelerate</TD></TR></TABLE>


just raise the idle, there is a little screw on top of the throttle body, somtimes there is a black cap on it or some gray waxy stuff either way scrape it off and turn the screw at lease 1 whole turn counter clock wise see if that helps, if not, you may want to turn it a little more.

disclaimer
this it not how you properly adjust the idle, but at long as my car stays below 1000rpm its fine