2006 Fusion V-6 Hitting On 3

You need to qualify "compression"

The important thing to consider when looking at compression, is: Do all of (4/6/8) the cylinders have roughly the SAME compression. A few PSI difference from one to the next is normal, anything over 10 PSI difference between cylinders means you might have a problem.

The next thing to consider is: you have only stated 2 of the 3 needed things to make an engine run. you need compression, spark, and FUEL.

Check all cylinders, record your compression, and let us know what they turned out to be.

Next, check to make sure you have fuel to each cylinder.

You say you know you have spark at each cylinder, might want to double check that.

If all three of these are OK... you might have something going on in your valve-train. Could have some stuck valves, and burnt valve seals... or worse..

Also, it would help if we knew what engine we are talking about... is this a locomotive, Volkswagen air cooled, rotary airplane engine, etc etc etc.

Thank you RVZ717, Forgot to mention eng. size. It is a 3 Litre, The car is running ruff on the 3 rear cylinders only. We have 170 lbs. on the front 3. The engine has oil leaks. Just wondering if low oil level could lead to this problem? It seems to be lack of fuel. I`m wondering if this is a built in safety feature????? Thank you, "B"

What's the computer say?

http://www.fordfusion.net/forums/viewforum.php?f=26&sid=1eda38371e511c8665f296fa766a833c

First it's :"the loss of power from the front 3 cylinders"

Now it's: "The car is running ruff on the 3 rear cylinders only."

"We have 170 lbs. on the front 3". You don't give the compression numbers for all cylinders.

"Low oil level".

"Lack of fuel."

You're in for the long haul.

Well lyn, I see it this way, if the car is running on the rear 3, it must have compression in those cylinders. I`m not a rocket scientist, but I do know the 3 components of "fire". If we`ve got spark,compression and no fire. Seems to me there must be a lack of fuel. I was just wondering if somehow the fuel coud have been shut down on the front 3 cylinders as a safety feature as a result of low oil pressure? Thanks "B"

I don't think oil pressure is the problem....are the spark plugs wet? Your injectors may be clogged, this is the first thing I would check if the plugs are dry....

http://www.fordfusion.net/forums/viewforum.php?f=26&sid=99c1116899705c7a4c25a639a246d477

It seems strange to me to have 3 with fuel and 3 without ????????????????????

You might have got some contaminated gas and the injectors are all restricted, those three to the point of less than minimum required....in other words if it is the injectors, they all need to be cleaned....I would also check filter/s in gas line and fuel pump/ line pressure...

If I were facing the car, I would look for fuel at the 3 front cylinders with a handy probe that is placed against the individual injector, that can since the injector's movement and fire the built in LED each time it fires. Or, I could spray some starting fluid into the air intake, and see if the front three cylinders come back to life.

Does this engine have cylinder on demand function?

What has changed since the vehicle worked correctly?

And what does the computer have for trouble codes?

I would still like to know the compression on every cylinder. Knowing the compression on only 3 tells us little to nothing.

Your spark plugs or coils may be contaminated with oil or water.

My Ford PU developed a miss that turned out to be a broken cheap plastic intake manifold that was flooding a coil and shorting it out. Each plug has it's won coil.

It cost over $1,000.00USD to have the manifold replaced. That's been three years ago and he's run like a top ever since.

Don't let the oil level get low.

yes, from extreme engine wear.

Fisrt off I would like to thank those of you that have responded to my questions. Today we pulled all the plugs and got 170 ish in all cylinders, and lots of fuel presure. Still hitting on rear 3 only, no code."WTF". Could we maybe have a timming problem? I`ll be honest with you guys, I`m old school and still run a flathead Ford v8. Gone are the days when a flat screw driver and a 9/16 wrench would get you back on the road. I`ll try the quick start thing. Have a good nite, "B"

I think you hit it. The points are pitted.

Based on what you found( compression, and fuel) I believe you may have misfiring coils. If the system was going to shut down 3 cylinders to save fuel or pollution, they would not feed fuel into them. That eliminates everything but the coils. Ford's coil on plugs seem to be prone to failures. If run long enough, the ECM will notice the cylinder misfire, and trip a code. Usually "random cylinder misfire" or the specific cylinder misfire. Rather than throwing money at a problem, just switch 1, or 2 spark plugs and coils from the back bank to the front, and see where the dead cylinders end up. An easy, no cost test.

Funny thing is that when we had one coil for all of the cylinders, failure was rare. Now that there are one for each cylinder, and they cost four times as much, they have become common failure items. This is not progress.

I misread your reply. You did not say weather you had fuel IN the cylinders when the plugs were removed. If the plugs came out wet, the answer I gave about coils stands. If there was no signs of fuel in the cylinders, then cylinder on demand, or non working injectors would be more likely. Sorry.

This is not an all-inclusive list, and it is possible under some circumstances to add, change/modify, or delete items. It is a basic performance testing menu.

Basic testing sequence:

Pre (cold) start attempt:

Check for proper battery voltage

Install fuel pressure gauge

Check for pressure and volume (check spec table in repair manual)

Install engine analyzer

Check for spark at a minimum of two cylinders

Check for injector pulse at a minimum of two cylinders

Pull codes

Check ECM/ECU data stream

Attempt to start: if starts and runs:

During running, recheck:

Fuel pressure/volume

Primary/secondary ignition scope traces

Injector operation (on scope)

ECM data stream

Bob C. (#8) may have hit on it. The engine control system may shut down one bank of cylinders for fuel economy at steady road speeds based on input parameters. The system may have malfunctioned and permanently shut down three cylinders. You either need to get a good shop manual or consult a knowledgeable repairman.

This will further loss of energy~~

I had a Ford Windstar with a V6 that suffered from a similar misfire situation. I ended up taking the intake manifold off, replacing the EGR valve, and cleaning the EGR return lines to each cylinder as 3 were plugged completely. This resulted in the EGR gases being delivered to the remaining 3 cylinders and immediate degradation of performance to the point where I thought the van was only running on 3 cylinders. After cleaning and re-assembly, it ran as good as ever.

An EGR system that sticks closed, or the passages become clogged will usually run better, or close to the same. The EGR system is an emission system that allows controled amounts of exhaust gas (no oxygen) to be introduced to the combustion chamber. If the exhaust gas is restricted below what is set by the factory, the change will be little noticable to the driver.

BUT, if the EGR valve were to stick open, the extra exhaust would lower the oxygen content below the point where combustion will readily take place. That will make your car feel dead. I tend to think that your EGR was stuck in an open position, and that cleaning everything allowed it to close again, improving performance to like new. Cheers.

'B' - Given that you have compression, oil is not the problem. Without oil on the cylinder walls, ring blow-by would increase resulting in lost compression. 170 psi is adequate for firing the cylinders. If the cylinders are not firing you need to look elsewhere for the problem.

I'm a little curios as to how you know that the front three cylinders are not producing power. I'm going to guess that you tested the front three cylinders pulling off a plug wire while the engine was running and looked for a dip in rpm, but you did NOT do this test on the rear cylinders because they were not accessible. If this is the case, there is a slight chance that you may have swapped the wires. But it is more likely that you damaged the ignition system. With a plug wire lifted, the spark is going to find a path to ground. With the old cap and rotor systems with oil filled ignition coils the alternate path would have been arcing within the cap. With the newer solid state ignition systems with dry ignition coils, the alternate spark path or the higher reflected voltage back into the primary will cause damage on some vehicles.

Not sure which engine version you have but some engines have variable displacement wherein the hydraulic lifters are collapsed and the fuel injectors shut off to acheive maximum fuel efficency. My engine cuts from 6 to 4 cylinders however there are others that cut from 6 to 3. This is accomplished electrically with control valves operated by the ECM.

You should be able to contact FORD and find out what you have.

Even if your engine is not a variable displacement type, collapsing of the hydraulic lifters due to low oil pressure can definitely decrease the cylinder combustion pressure in today's close tolerance engines.

Things to check: Oil filter check valve operation, Variable Displacement Control elect fuse, cause of oil leak, loose or ruptured oil gallery plug, loose valve train assembly allowing oil gallery port to "free flow", loose VCD valve assembly.

Also; There is an internet site "ASK A MECHANIC" that is excellent for getting advice and direction.

Good luck!