2001 V70 T5 Running Rough after ETM Replacement

[Gymbo]

The car was running great until last week I drove home about 5 miles for lunch and when I started it up to come back to work it would barely idle and went into limp mode. No check engine light but I pulled codes after work and showed ECM-91F0 ETM internal fault. After a quick email to XeMODeX I had a new ETM on its way to me. (kudos to XeMODeX customer service)

It was going to be a week before I could get into the local mechanic who installed the XeMODeX 3 years ago so I decided to install it myself. In retrospect I am questioning that decision...LOL

After watching a bunch of YouTube videos I removed the airbox, turbo charge pipe, radiator fan assembly and the plastic pipe that goes from the intercooler into the bottom of the ETM.

I installed it on Saturday and at first all seemed well. In fact, the car felt more responsive than before. Then last night while running to the store the check engine light came on and was for Misfire Cylinder #3. I cleared the code to see if it would recur. This morning it started a bit rough but it didn't throw a CEL. I had to get to work so I drove it to work and once in my parking lot it idles smooth, but not quite perfect.

The questions I have is there anything I could have done wrong relating to the ETM install that would cause this? As far as I know I got all the intake plumbing and vacuum lines back together snugly. I have tomorrow afternoon off work and am going to recheck my work.

I replaced the MAF 3 years ago when I originally had the XeMODeX ETM installed.
New VOLVO plugs 1 year ago - I do believe that it was cylinder 3 plug looked like it was running rich... I wondered if it might be a bad injector dumping too much fuel or now wondering if I have a weak coil. Had been thinking about installing a new injector on my next parts order.

XeMODeX also suggests changing the ECM relay when installing the ETM...it's ordered and I'm still waiting on the part.

Planned maintenance new air and fuel filters. Though the air filter looks fine, the fuel filter was done 50k ago.

I am an hour from the nearest indy Volvo shop.... so before I start throwing parts at it is there anything I should specifically check on the work I did?

From what I've read scouring the forums a misfire is often related to a bad coil pack. It's just the timing right after I completed the throttle body work has me questioning.

Any thoughts are appreciated....THANKS!

[firstv70volvo]

Did you install a new ETM to manifold gasket? This is an important item never to reuse since it will cause an air leak and idle problems. Check to make sure the intake tube is fully seated on the ETM; I use a mirror to check if the back side is fully seated.

For the misfire on cylinder 3 I would move the coil to another location to see if the misfire follows the coil. If the misfire does come back and it's the coil don't drive the car since this can harm the (expensive) catalytic converter, replace the coil right away.

[Gymbo]

Thanks for the response.

Yes, the replacement XeMODeX ETM came with a new OEM Volvo gasket, which I
used.

When I initially fired it up it idled awful and I discovered I didn't get the intake tube seated on the ETM. I loosened the clamp and believe I got it seated. That might be something to re-check.

Yes, I was thinking of moving the coil to a different cylinder to see if I could duplicate.

One other thing I forgot to add, I recently noticed I have small exhaust manifold leak...it's barely detectable and I was going to have my mechanic do that repair next month. Not sure if that would cause a misfire.

[Gymbo]

Drove it home after work. Stumbled a bit right after it started....a gave it a little throttle and it smoothed out and drove normally on the way home. It's a 7 minute commute. Upon pulling into my carport the idle was smooth but just a little off of how smooth it was before the ETM acted up last week. It did not throw a misfire code driving it today. Thinking I will make sure the intake tube is properly seated on the ETM. Now that I've done it once, taking the airbox and radiator fan assy out shouldn't take all that long.

[abscate]

Any leak in the induction path will give you a horrible idle, do check all the hoses

2 turbo clamps
Clamp at the bridge pipe
Clamp at bottom of inter cooler
Clamp top of inter cooler
Clamp at ETM

Hosesat the intercooler are easy to install half on/ half off

[Gymbo]

After inspecting all the intake pipes and vacuum lines, I could not find any that were loose or not fully seated.

So since it was running great prior to throwing the Misfire Cylinder #3 code I took a flyer and replaced the #3 coil this morning before work.

Fingers crossed, but it ran normally this morning on my commute to work.

[volvolugnut]

Exhaust leak can messup the O2 sensor reading and result in air fuel ratio being off. Then you have a miss fire
Volvolugnut

[Gymbo]

Thanks. I just ordered new O2 sensors and exhaust manifold gaskets.