Diagnosing hesitation (Ford Five Hundred)

[David]

Misc BS
Hello all

This is my first post here, and I am hoping it will be far from the last.

I am just starting out in engine maintenance (from an IT service background so diagnostic technique is no alien concept to me), so please excuse my personal hesitation to chime in very much until this post.

I have a few niggles with my Ford Five Hundred but this one is one I want to figure out before the coming Canadian winter makes it soul destroying to both diagnose or to just put up with on the roads.

The Problem
2005 Ford Five Hundred 3.0L Limited. 200’000 kilometres (124’000 miles)

Hesitation from a standstill. Lean code P0174. Still looking for underlying cause even while it seems to have gone.

Quick History
A month ago I started having severe shaking/hesitation when trying to move from a stationary position. I would have to put the gas pedal back up then softly feather it down to get the car moving without having the engine shake all it’s bolts loose. Other than moving from a stand-still, the engine does not hesitate or vibrate or react in any way.

I also started getting P0174 – Lean code.

As is the way, both the hesitation and the lean code were intermittent.

What I Tried So Far
Some quick Googling/YouTubing told me that the fuel filter could be holding up the fuel flow, and I don’t remember it ever being changed in the vehicle’s 4 year history that I am aware of, so I figured I would do that first. I took it off, it was rusty as hell and looked like it was long overdue. I tried blowing through it and nothing. No air flow whatsoever.

I’ve done that and the problem has largely disappeared, except it did it once more. It has gone away now, except for a very slight and imperceptible shudder when accelerating from a standstill. Come to think of it, the problem has not come back since then…I am waiting for it to, though. It seems the ghosts of the underlying problem are still haunting me.

What I Think
After some more Googling/YouTubing, I found that there could be a vacuum leak and the fuel filter was just in need of a change, anyway. I listened to the engine and heard a slight hissing on the left side of the engine where the manifold is. Could be my own imagination or wishful hope playing tricks on me.

I purchased some carb cleaner and did some investigating. The engine RPM dipped a little when spraying this hose where is connects with the engine block (??) but did not return to normal rev range like ETC demonstrates.

Through looking online at engine diagrams and YT videos of various types, I think this is a fuel injector?

View post on imgur.com

I may have changed the filter and flow has largely returned to normal, except for the one time it was hesitating with the lean code.

Is this something that should be causing the engine revs to drops slightly and stay there? From what I can tell, this is a fuel injector and no air should be passing to be leaking in, unless it is mixing in the the fuel in which case there was also be some fuel leaking and some serious misfiring, right?

So, my thinking is that the hissing is from a leaking head gasket itself, albeit a very slight one. Or maybe the hissing on that side is in my imagination or misunderstood from a normal kind of noise and not problematic at all… and that the one spout of hesitation is from the computer re-balancing fuel/air mix after the filter was changed, and that the problem really has gone away entirely. (please say yes)

Yes/no/maybe/dad?

Topic

[college man]

When the fuel filter was clogged it may have hurt the fuel pump. check your fuel
pressure with a FP gauge. Try cleaning the MAF with the correct cleaner. Also
check your PCV hoses for holes. more in this link.

http://www.ericthecarguy.com/faq/solving-automotive-performance-issues

[David]

Thank you, college_man.

I’ve been trying to find my PCV valve for days and days. Can you see it here anywhere?[IMG]http://images.tapatalk-cdn.com/15/10/27/baa565de7579077db133a596d67b8b7d.jpg[/IMG]
[IMG]http://images.tapatalk-cdn.com/15/10/27/13f94774beee1f3f66e3319088926567.jpg[/IMG]

Yes I’m aware my throttle body needs cleaning 😉

Sent from my iPhone using Tapatalk

[college man]

see if this helps.

http://www.fixya.com/cars/t13930296-locating_pcv_valve_2005_ford_five

http://www.focushacks.com/images/pcv.jpg

[Bill]

It appears like the rubber bushing in the engine torque mount is destroyed. That will make the engine thrash around when stepping on the gas and is a common failure on those cars. I would continue to search for a vacuum leak for the lean code.

[David]

Thank you for your response, Wysetech.

I have looked in to the engine torque mount and it looks like that could be something to watch for. Maybe the lean code comes up as a result of the severe vibrations wiggling something loose? I could not find a leak for the life of me, and no lean codes have come up for a little while now. I still think that it is a result of the combination of clogged fuel filter/old air filter/sticky PCV/dirty MAF/dirty throttle body, because things started alleviating as soon as I did the two filters.

I am asking around friends to see if anybody has a fuel pressure gauge so I can check that I haven’t damaged the pump with the crappy fuel filter.

Yet another thing to fix on the 500 before the real frost comes. Maybe I’ll get lucky and find a replacement rubber gromet instead of buying the whole thing in a kit like seems normal on the market.

I cleaned the MAF sensor and the throttle body.

I have found the PCV valve and disconnected both the hose elbow and the electrical plug-in but cannot for the life of me get the tiny nipple to wiggle out so I can turn the thing CCW and remove it – see image.

Any tips? I have tried using a screwdriver to encourage it out while I turn but it was both a very tight spot so I struggled and I was running out of sunlight. Is that a kind of tamper-proof thing that must be snapped in order to get the thing off? I think I read that somewhere that they will always break when removing and a new one must be purchased to replace the old one.

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