1999 C70 Mis-fire type symptom at low RPM

[Kazthebassman]

OK, here's the update. I put a can of Royal purple injector cleaner in 12 gallons of gas used 10 gallons. A very noticeable difference car ran nice no stumbling at idle. So I filled up and put another can in. Car ran near perfect til the last 2-3 gallons in the tank. So I figured, it has to be a dirty ETM..maybe injectors. I wasn't near my royal purple supplier so I put some Chevron injector cleaner in and decided I would clean the ETM the next day(yesterday).
Etm was dirty but cleaned up fairly easy. I didn't drive it til this morning. A little hard starting but ran pretty well then the hunting started, then limp mode in the last 2 miles of my 15 mile commute. Same on the way home but into limp mode with about 6 miles to go.
My Air intake sensor looked dirty, so I swapped it tonight, with an old one that may or may not be ok. No change.
I checked my coils supply voltages several days ago as Ascate suggested. Supply is OK. The running changes in 1-3 are minor when the problem is not there. When the problem is there those changes would be masked by the 'stumbling idle. Besides the coils are almost new, maybe 300 miles on them(not OEM). The problem existed prior to the coil pack replacement.
I have a Actron CP9550 code reader. There were no codes stored a few weeks ago. I read codes tonight The Codes are P0351,P0352,P0353,P0354 and of course P0355. The description of these on my code reader is "Ing Coil A Prim/Sec Ckt Malfunction for P0351 and "B-E" respectively.
Is this a common code sequence, after the vehicle goes into 'limp mode' ? Or should I be chasing a different problem not related to ETM?
Also the cruise control did not work.
Thank you for any help with this issue. This unfortunately for me is my only car other than a Celica project that may be done if if I wasn't always working on my Volvo. Thanks again.

[abscate]

If your ETS light is not on, and the bulb is good, I would stay on your ignition troubleshooting path until you can stop those misfire codes. How are the wires to the coils? Inspect that loom

[Kazthebassman]

Thanks for the input Ascate. Always appreciated, now and for past help as well.
I had after market coils on.(finicky Volvos) I put the old OEM coils back on. Same symptoms but no hidden misfire codes.
No codes at all. I have inspected the wires fairly well too.

I am now following the Xemodex flow charts. I want to eliminate the ETM wiring. That's tomorrow's plan.
I may throw a different MAF at it, if it points that way. The one that is on the car was bought used, maybe 5 months ago.
My code reader states MIL off (ETS off) and it does light, when ignition on and not started. Bulb OK.
I will update tomorrow.

[abscate]

Its very common to have misfires and no misfire codes. They don't set that easily.

The ETM on the turbo is a tough nut to crack - I would take off he intake manifold and inspect all the vacuum hoses while you have that off. Its mostly labor and cheap gaskets and parts.

[Kazthebassman]

It was the ETM.
I installed a Xemodex unit today. It was difficult to trouble-shoot, as it only happened when the car was at full operating temperate for a while. I had to get it hot then, trouble shoot using the Xemodex flow chart:
http://xemodex.com/us/knowledgebase/etm ... 1999-2004/

With the car warm, I was working with the "fuse #2" step, I was hearing a relay engage that was not the ETM moving, yet sounded like it could be.
I disconnected the ETM electrically. I still heard the 'relay'click. This told me the click was not the ETM moving and that the sound was a different function.
The conclusion is the ETM plate was not moving/had difficulty moving, when the vehicle was warm. Voltages had remained in spec at the connector.
I ordered the Xemodex unit late Dec 21. It was shipped in the morning of the 22nd and arrived in NJ in the morning of the 23rd.
Heavy rain and exhaustion forced me to wait til this morning Dec 24th to install it. It works very well.
There is a minor drop at idle sometimes. Nothing at all like it was at all. I can drive to visit my family for Christmas!
I ordered a new Bosch MAF from German Auto. I intend to reinstall my new after market coils and maybe new plugs along with the new MAF in the next few days.

[misha]

Which spark plugs you installed?

[Kazthebassman]

@ misha (spark plugs)

I had run ngk V-Power Spark Plug; BKR6E for a while.
I had changed to what the Hanes maunal says : Bosch FR7DPP+
I can not attest to the Bosch FR7DPP+, as I had ther ETM issues present when I installed them. They presently have black carbon on the outer ring and the ground electrode has reddish brown deposits. I don't believe this is very bad but I want it all new with my new ETM.
My vehicle is a 99 C70 cab 2.4 T

[Kazthebassman]

@ misha (Spark plugs)
owner's manual states : "Champion RC8PYP "

[Kazthebassman]

http://www.sparkplug-crossreference.com ... _PN/RC8PYP

[misha]

Don't rely much on Haynes manual.
Turbo and non turbo cars can use the same spark plugs like those Ngk bkr6 since they are the same like bosch fr6dc or fr7dc.The most IMPORTANT thing which makes a difference between turbo and non turbo cars is spark plug gap.It's more critical for turbo cars.

Ngk bkr6ix (iridium) are proper plugs for turbo car.The most important thing is that spark plugs for turbo cars are single prong ones.
Why you just don't install oem volvo spark plugs for turbo cars and save yourself and a car from troubles?

I can say to you from my experience and other's experience that cross reference,allthough refer to equivalent spark plugs,in real life it's much different and usually don't work for a lot of cars.Especially those fancy platinum multi-prong spark plugs.

These cars love oem things and nothing can beat that.Turbos are especially picky about spark plugs.