99' S70, 5-speed, surging idle

Post by **850 LPT** » 31 May 2019, 09:00

Hi folks,

I've been driving the new to me S70 around and it has an idle problem.
When I come to a stop and take it out of gear the idle starts surging and sometimes the engine cuts out.

From doing a little research on here this may be pointing to a bad ETM. The ETM is a yellow label unit and the car has 209k on it now. I was hoping this would last a little longer but maybe not.

Would you guys agree or is there something else I should be looking at first?

Thanks, Dirk

krenekj · Post by **krenekj** » 31 May 2019, 11:41

When I suspected ETM issues, XmodeX was a great resource. They had a good flow chart one could follow to diagnose a failing ETM:

ETM Diagnostic Flow Chart.pdf: (142.07 KiB) Downloaded 181 times

Their techs are also very responsive to submitted questions and calls. That may have changed now that they only sell through authorized resellers, but it's worth a try.

https://xemodex.com/us/

Of course there are other issues that affect your idle, but if you suspect a ETM, they are a good resource to get better clarity on the ETM's functionality and impact to your issue.

Thanks.

Post by **850 LPT** » 31 May 2019, 12:43

krenekj wrote: ↑31 May 2019, 11:41 Of course there are other issues that affect your idle

I would like to learn more about this.

That flow chart looks to be very helpful.

I was just poking around their website and it looks like one could order from them directly again?

They suggest to replace the MAF along with the ETM. I don't know but that is getting pricey.

I need to drive the car more to complete the drive cycles and see what lights come on.
The battery went dead on me while I was working on the car and I am just now starting to drive it more regularily.

Thanks, Dirk

Post by **abscate** » 31 May 2019, 16:43

Dirk, that 99 NA has an idle air valve like a 1998. Denso ingnition and air/ fuel management.

Give that a clean , then let’s look at fuel trims

At under 200k, leave the ETM alone for now

Post by **wizechatmgr** » 31 May 2019, 16:58

Could also try running it without the MAF connected I believe. Typically if performance improves it's a sign the MAF "might" be going bad.

Post by **850 LPT** » 31 May 2019, 18:22

Thanks guys, I will investigate that idle control valve and clean if I can find it. Interesting about disconnecting the MAF, will try that too.

Post by **abscate** » 31 May 2019, 21:41

850 LPT wrote: ↑31 May 2019, 18:22 Thanks guys, I will investigate that idle control valve and clean if I can find it. Interesting about disconnecting the MAF, will try that too.

Comes off the snorkel aft of the throttle body. Dumps air into the intake manifold by a long hose.