mx5roadster

iTrader: (3)

Need other's thoughts on my idle issue...

Car is a 94 with a stock 99 motor, VICS manifold, 99 throttle body, 94 sensors and injectors. Currently running on MSPNP.

Car is idling a bit high (950-1000) and looping more than I think it should (100-150 rpms).

All symptoms point to a vacuum leak. I've replaced all gaskets and seals on the intake manifold - did not solve the problem. Smoke test did not turn up anything. Vacuum gauge sits at 22inHg at idle. Timing belt is aligned correctly.

I'm currently thinking I have an exhaust leak which is throwing off the wideband, but my tune may also be off. Fairly new to MS tuning and I'm stumped on this one. Any thoughts?

Edit: I think I'm idling on the lean side. Would that cause this? I stated with the 94 base map and added fuel all around. AFRs are in the ballpark and car suns good everywhere else.

curly

iTrader: (25)

Do you have a wideband?

sixshooter

iTrader: (12)

Says he does in description.

Misfires and exhaust leaks can cause a lean condition. So can tune. I'm using my phone so I didn't open the msq yet.

mx5roadster

iTrader: (3)

Yes. Noticed the log shows in O2 voltage and not AFR, still trying to figure out how to fix that.

noob question - if the MAP shows completely stable at idle, I shouldn't have a vacuum leak right?

sixshooter

iTrader: (12)

A stable MAP does not indicate or contraindicate a leak.

curly

iTrader: (25)

Ah ok, I couldn’t find afr or o2 voltage in the log. There’s a write up on how to change from bolts to afr in the MS section, I think it’s a sticky.