Wahooz

Hi all, hopin' you can help out. I've got the infamous "shudder" whenever I come to a stop and push the clutch in to engage 1st. I've done the MAP whack, cleaned the IAC, and even replaced the MAP but it still happens. I'm running an AEM EMS, so it's not like the ECU is learning and compensating for the change in temp and humidity here in VA. It feels like the car is going to stall whenever I push the clutch in from a stop. It's drivin' me crazy! Not sure what it could be as it just started doing this recently and my EMS hasn't been modified since installed. Does the AEM EMS adjust itself like the stock ECU? Thanks for any insights you can share--

negcamber

Go back to your tuner...there is a problem with the fuel maps down low. He may need to ride with you with a laptop plugged in to do some street tuning. I've got an EMS too and also had to visit my tuner a couple times to tweak the maps so the car runs best for my driving style. Like you said, it's not like the oem that learns your driving style...someone has to teach it.

Wahooz

Thanks for the response negcamber...but I'm still wondering why it just started doing it? I had my EMS tuned about a year ago, and this problem only recently surfaced. I didn't change any major components (I replaced the starter, but wouldn't think that has any effect) since it was tuned last year. If it was a bad tune, I would imagine it would've done this from the get go, not after nearly a year?

Red Barchetta

It's most definitely not your EMS because I'm running stock and I've got the same problem...

qbmurderer13

Not sure why you would even try the MAP whack or cleaning the IAC. If its only doing it at a stop when you push the clutch in then it sounds like a clutch problem.

Red Barchetta

Damn I had a feeling it would be... yikes I hope just a fluid flush will do.

negcamber

Regardless...a quick ride with your tuner and his laptop should be able to diagnose the issue.

Have you made any mods since adding the EMS? That might impact the tune.

raymo19

I had the same problem when the ambient temperatures warmed up this year. negcamber is spot on. My tuner added fuel down low and the problem went away.

It's unlikely to be a clutch problem as you'd probably have other symptoms/problems.

Good luck.

Red Barchetta

What if its with a stock setup? Could it be the fuel pump or even the filter?

negcamber

^^ Unlikely to be fuel pump...it is pretty binary...on or off. And we don't have a fuel filter...just a mesh sock over the fuel pick-up.

BTW...diagnosing the OP's car is somewhat different than for an OEM car. Almost always the EMS should be the first thought with drivability issues as described.