Hesitating Duratech

[simple_gifts]

Vehicle is 2006 B2300 67K miles
2.3L Duratech.

I noticed this problem since almost new, vehicle has 1 second hesitations every few seconds primarily during warm up. Not very pronounced and not enough to prevent from acceleration; the situation is best described as having a giant AC compressor cycle on an off; sort of that parasitic drag type of hesitation. Hesitations are becoming more frequent and seem to disappear when the "core engine temp" is at fully operating condition. (not just when the temp needle reaches the middle) A five minute sit, can trigger the situation again.

Someone who borrowed the vehicle has also noticed it, it is not my imagination.

Any thoughts; I don't have clue. May just wait for the CEL, but I'd rather not be 450 miles from home when the culprit rears its head.

Plugs and everything ignition is original; passed OBDII based emissions test just two weeks ago, no CEL.

 

[zanzabar]

My first thought would be throttle body. I just cleaned off one a 2.3 2005 Focus and it was having the same hesitation you are experiencing. FYI the buildup was sticky and tough, I had to resort to sandpaper to remove the bulk of it, since the spray cleaner stuff I was using was not having an effect. Also, the housing is plastic, so you'll need some plastic safe spray, not the traditional throttle body cleaner.

 

[Bgallagher]

I agree with the trottle body. Also, pull the plugs and check them out. It seems to me like they might need to be regapped. A sparkplug can tell a lot about your engine

 

[zanzabar]

RE: gaps, I believe the listed is 0.051" but there is some talk around the internet of going higher. The Motorcraft double platinum ones out of the box were 0.044" I think, and I gapped to 0.055. Be careful not to touch the center electrode when gapping these, only grab the outer arm with pliers.

 

[simple_gifts]

Sorry about getting back so late, forgot I posted this until I was driving around this weekend and the situation was cropping up again; Thanks for the input. Will try the TB first, then the plugs. I think these are 100K plugs and most of my driving has been highway; I'd be a bit disappointed if they needed replacing at less then the recommended interval.

-Thomas

 

[TFB1]

I disagree on all of the above, clean the mass air meter... If dirty it will cause a lean fuel condition which leads to hesitation and sluggishness... New plugs can help in such situations but the problem is usually back in a few K mi, still at 65K mi I'd be replacing them...

 

[simple_gifts]

Update:cleaned the MAFS and the situation is much better now. I consider it fixed. Who says a mechanic can't come in a can? Will be cleaning the TB next weekend and I need to do coolant.

I will give the nod to Ford for making servicing the sensor almost a joy.

 

[MysticGold04]

Are you talking about the Mass airflow sensor on the intake air tube? I cleaned mine not too long ago as well. I also cleaned the TB, as it was really gummed up.

I have heard that the IAC valve can cause issues like that as well. Every once in a while I will get minor hesitation accelerating easy in 4th gear. It does not do it in any other gear so I haven't taken the time to really investigate.

 

[simple_gifts]

Yes the air tube one; What is the IAC and where is it; what does it do?

I haven't delved into the TB yet. Will be checking that out shortly. Any tips on that? Do I need to remove it from the vehicle?

 

[MysticGold04]

I didn't remove mine. I just removed the air tube and sprayed cleaner in it with the engine running as the instructions said to. To be honest I didn't notice much of a difference after cleaning it, but it was pretty dirty.

I believe the IAC valve is on the passenger side, if you are facing the front of the car. It is up near the top part of the hood- it has a metal shield around it. I have not attempted to take it out yet to clean mine, but I may just replace it soon.

 

[mechtech2]

This seems electrical - an intermittent glitch.
Coils and ignition modules can be funky with cold/hot conditions.
A regular misfire or uneven idle could be all sorts of components.
But running fine with a cut out indicates a connection is being interrupted. Maybe a TPS .

 

[TFB1]

Originally Posted By: simple_gifts
Yes the air tube one; What is the IAC and where is it; what does it do?

I haven't delved into the TB yet. Will be checking that out shortly. Any tips on that? Do I need to remove it from the vehicle?


I wouldn't touch it... Years back(early '90s) Ford TB were supposed to have a coating that prevented dirt from sticking to them and what did wasn't enough to cause a problem... Cleaning could supposedly damage the coating...

If you do decide to clean it, I recommend removal as any dirt you remove will likely find it's way inside the engine, at least into the intake system...

The IAC can get gummed up and cause idle issues(esp cold), I do occasionally clean those, usually with WD-40 or similar that leaves some light lubrication... I dunno about the later IAC, but harsh cleaners could damage the ones of early '90s and back... Now in my later years, I mostly go with "if it ain't broke don't fix it", though cleaning the MAF meter every year or two is good preventative maintenance...

 

[steve20]

Originally Posted By: TFB1
Originally Posted By: simple_gifts
Yes the air tube one; What is the IAC and where is it; what does it do?

I haven't delved into the TB yet. Will be checking that out shortly. Any tips on that? Do I need to remove it from the vehicle?


I wouldn't touch it... Years back(early '90s) Ford TB were supposed to have a coating that prevented dirt from sticking to them and what did wasn't enough to cause a problem... Cleaning could supposedly damage the coating...

If you do decide to clean it, I recommend removal as any dirt you remove will likely find it's way inside the engine, at least into the intake system...

The IAC can get gummed up and cause idle issues(esp cold), I do occasionally clean those, usually with WD-40 or similar that leaves some light lubrication... I dunno about the later IAC, but harsh cleaners could damage the ones of early '90s and back... Now in my later years, I mostly go with "if it ain't broke don't fix it", though cleaning the MAF meter every year or two is good preventative maintenance...


good memory^^^I remember it being coated with a Teflon type caoting--supposedly sped up the intake charge

 

[MysticGold04]

Originally Posted By: steve20

good memory^^^I remember it being coated with a Teflon type caoting--supposedly sped up the intake charge


I did notice mine did seem to have some type of coating on it. (It was white) Not a normal metal TB plate like in my Toyotas. I used Intake/TB cleaner to clean it.