99 v70 GLT missfire/shudder in 'D' at stop light

grigalid · Post by **grigalid** » 21 Apr 2015, 05:46

Periodic issue I have been having, hoping for some input.

Occasionally while in 'D' at a stop the car will seem like it missfires. Idle revs seem steady but it seems as though the engine just dies suddenly for a second. If this is happening it usually also happens during initial acceleration. There are no symtoms while driving and hard acceleration on the highway. When put in neutral at the stop it appears to go away. The car is usually well warmed up, not sure if it has happened when the engine is cold.

The car has a new ETM xemodex throttle body. No check engine light, I will check for hidden codes tonight with my basic OBD2, but my vida died.

I was thinking coil pack etc, but the car has direct ignition ($$$). If a coil pack was causing problems would I feel it while highway driving? Can't afford to replace them all, what would you all recommend?

Thanks ahead of time,
Dani G

Post by **erikv11** » 21 Apr 2015, 06:47

Are there no codes or a CEL? Are the plugs in good shape?

I would expect a coil pack problem to throw a code. My first guess was going to be ETM, next would be MAF. On the 98 and earlier you can unplug the MAF as a test, this will throw a code for no MAF signal but the car goes into default and the stumbling should go away. Just reset the code when you are done.

grigalid · Post by **grigalid** » 21 Apr 2015, 08:16

I should have metioned that the MAF was replaced when I did the ETM. I will inspect the plugs as soon as I can.

As mentioned, no CEL, I will confirm there are no codes tonight.

grigalid · Post by **grigalid** » 11 May 2015, 09:44

99 Volvo V70 GLT 2.4L (turbo) 280 000kms.

Recent replacements: xemodex ETM, MAF, spark plugs, fuel filter, an evap sensor.

Symptoms:
Engines appears to miss while at red light in drive and during initial acceleration. No symptoms in neutral or park. Sometimes difficult to tell if this is occurring at cruising speeds, but it does happen.
NEW- happened twice. Major engine chugging during take off, low engine power. Both times engine was cool and was going up a hill. (I live on a hill)

So I replaced the plugs.
There was no CEL but OBD2 codes are P0352 and P1113

Trouble Code: P0352 - (ASE)
System: Powertrain
Subsystem:Ignition System or Engine Misfire
DTC Description: (Ignition Coil B) Primary / Secondary Circuit
Location:Ignition Coil B
Analysis: Circuit Issue

Question: Is ignition coil B cylinder # 2? (second from passenger side?)

Trouble Code:P1113 - (Manufacturer Specific)
System:Powertrain
Subsystem: Fuel and Air Metering
DTC Description: (Bank 1 - Sensor 1) Internal Resistance Too High
Location:Bank 1 - Sensor 1

Codes reset and only the P0352 came back.

I would think obviously there is a misfire/coil issue. I will jiggle the wires while on idle this evening, see if I can detect a wiring issue. I will also have my wife put it in drive as the symptom is more evident while in D. If it was a coil failure would I not notice this while in park?

Any ideas would be helpful. How can I test the wiring circuit/signal from COP driver circuit?

Post by **Brucebo** » 11 May 2015, 10:43

I would expect it to be a coil pack. If it misfires enough your cel/obdII will tell you which cylinder. At high revs it may not be noticeable. A coil pack can fail and still appear to work perfectly to the computer. What often happens is they start to develop a high voltage internal short, bypassing the spark plug. The actual coil and electronics are still functioning perfectly. If it's marginal one thing you can do is regap your spark plugs to a smaller (often corrected) gap. This lessens the arc voltage of the plug to below the shorting voltage. This often "cures" the problem, at least until you get a new coil pack.

Post by **erikv11** » 11 May 2015, 11:11

OK, there is a code now, and it sounds informative. Yes the p0352 points to cylinder 2, you expect this code from a failing coil pack.

I would move the suspect coil pack to another cylinder, and see if the CEL follows it (do you get a p0351 code with the suspect coil pack on cylinder one?). If the code doesn't move, then maybe the problem is the wire to cylinder 2, not the coil pack itself.

grigalid · Post by **grigalid** » 11 May 2015, 13:21

Great, thanks.

@Brucebo- thanks for the tip, will try the re-gap
@erikv11- perfect, that was in my plan for this evening once I got confirmation on the cylinder B thing.

I will keep you posted, thanks again!

grigalid · Post by **grigalid** » 12 May 2015, 04:52

So I jiggled the wires while on idle, no change. I then swapped coils and of course the issue hasn't come back. I will keep you posted once the code re-appears. It was sporadic before so this isn't that weird, just a pita as I would like to fix this.

Thanks again for the advice.