Rough Engine Starting

[seanm]

Hello All -- 2005 XC70 63K miles. I do minor DIY - but have no garage, tools or skills for most stuff.

In the last month it takes a few ignition turns for the engine to turn over and fire up. Not all the time but every few days and seems to be gradually happening more often. . Happens throughout the day - not necessarily first start of the morning. Starter sounds fine and not slow. Idle and acceleration seem fine - with maybe some hesitation at times. but nothing significantly noticeable. I would rather deal with any preventative maintenance now before it worsens and causes other issues.

** Installed new plugs and fuel filter and air filter about 6 months ago.
** Placed a surgical glove over the oil filler and it sucked - which I understand is a good thing? and indicates the PCV is not clogged?
** Battery checked out fine about a month ago (but before this started happening)

Would these be the next steps?:

check on any codes thrown;
checking battery again;
cleaning/replacing the MAF sensor;
checking/cleaning the ETM/Throttle Body?
and/or?

I have 6 months remaining on a VIP Total Care Warranty that may cover the MAF sensor - but not the throttle body. Dealer has to do any warranty work and wants $120 to "diagnose" and pull codes. So I am thinking to go my Indy first - have the codes pulled and then go from there.

[ethansdad]

My next step would be cleaning ETM-throttle body. Reason that if MAF would most likely throw a fault code if out of range. Also when check connections and wiring to coil packs (may have wiggled loose when replacing spark plugs). Had same problem with my 2001 then ETM finally gave out (no CEL ever illuminated, replaced under warranty thank god) and the problem never appeared again.

[seanm]

Maybe this will help others with the same symptoms. To update -- No Check Engine Light; No Codes, wiring to coils seemed fine.
After reading more through this forum, I decided to try a bottle of BG 44K fuel system cleaner. So far it seems to have solved the problem. After the BG and 200 miles, now it starts right up and runs much smoother. For what it's worth - I also had an indie suggest to stay away from discount (Costco) and off-brand gas and recommended sticking with quality gas brands (like Chevron or Shell).
I wonder what others think about this?

[Astro14]

I have found, several times, with several different cars, that the cheap gas causes running problems.

So, I tend to buy Shell, Exxon, Mobil and once in a while Sunoco or BP...but rarely at the rest of them...and very rarely at the quickie-mart places...it seems to me that now, with the E10 fuel, that gasoline is more variable in quality...more susceptible to degrading while it sits. Certainly this is true in outdoor power equipment, where I've been through a few carburetors that get hopelessly gummed up from E10...

[ddandino]

I think Astro14 might be right ... during hurricane Sandy and the aftermath I was only able to get 87 octane gas. While I was suprised how well the car ran ( I kept it easy but definitly did notice a decrease in power ) I was suprised on how long my crank times to start became. This went away as soon as I was able to fill with 93 octane.


Dan

[seanm]

Makes good sense Astro. I would also suspect with the higher price, the high-octane at the quickie-mart/discount gas stations sit around much longer.

I have heard an oil change is suggested 1 tank after using BG 44K fuel cleaner. Do people here agree?

[Thames]

Have you cured your problem ?

[Allen]

Makes good sense Astro. I would also suspect with the higher price, the high-octane at the quickie-mart/discount gas stations sit around much longer.

I have heard an oil change is suggested 1 tank after using BG 44K fuel cleaner. Do people here agree?

Do not change your oil just because you used injector cleaner. I wish I knew where this absurd thinking is coming from.

[sjonnie]

For what it's worth - I also had an indie suggest to stay away from discount (Costco) and off-brand gas and recommended sticking with quality gas brands (like Chevron or Shell). I wonder what others think about this?

http://www.toptiergas.com/

Also it's worth using a bottle of Techron Concentrate Fuel System Cleaner to clean the fuel system every 5K miles or so. It's the same additive they put in TopTier gas.

[seanm]

Yes Thames...Since the bg44 fuel system cleanse, my starting performance has been much improved - with no more long cranks before firing up.

Allen - I thought I read in a thread here somewhere about oil breaking down faster right after a fuel cleanse, but don't know what the logic behind it was. Regardless, I have kept to my normal 3K oil change routine.

Also I am wondering... any opinions if running Ethanol-free gas is significantly better (or not) for the xc-70?