Contour Enthusiasts Group Archives Forums General Troubleshooting Duratec V6 loosing power (read other posts & FAQs)

I have a Ford Mondeo with a Duratec V6 2.5L engine, my problems started with some intermitent and transient engine power drops.

Turns out I had a clogged fuel filter so I changed it, the problem didn't go away... So accrding to my mechanic I needed to change the Fuel pump, so I changed it and the problem didn't go away... After some time I got failure codes 171 and 174 (Lean fuel mixture in Bank 1 and 2), my mechanic changed the pump for the second time (blaiming a possible faulty first pump) and the problem remains.

Over the weekend I had the MAF and TPS sensor replaced and replaced the main cat with a tube and the problem persist with the only difference that I haven't seen the 171 and 174 codes yet (they eventually appear after a few days)...

The problem is getting worst: Now when ever the engine warm-up and maybe after 5 minutes of driving the engine starts loosing poower, and even if I floor on the accelerator the rev's don't pick-up and after a few seconds the engine starts coughing (or farting).

I was suspecting the IMRC but it seems the IMRC fails when they don't open at higher revs (+3,500), my car gives me this problem at lower rev's around 2,000.

Will appreciatte any orientation so I can go work on my car tomorrow.

BTW, the dealer says it the Fuel pump because I didn't put the original Mondeo Part number that they sell 4x the Contour replacement I'm using, screw them both pumps are for the Duratec V5 and pump same psi's.

Sorry for the lenghty post but I'm frustrated by this month old problem that keeps getting worst.

Thanks,

Welcome to CEG!

• Make sure the secondaries are still hooked to the linkage.
• Check the PCV system for a major vacuum leak between the intake and valve.
• Check for vacuum leaks at the intake gaskets.

Guy's I've been fiddling at www.fordmondeo.org but you definetely have a lo more technical info on the Duratec V6 and related systems.

One more question:
by Check for vacuum leaks at the intake gaskets you mean the UIM and LIM gaskets?

Thanks!

Welcome. Check all vacuum hoses too. Test by spraying some carb. cleaner on them. If it idles faster when you spray on that location, you found your leak.

From TSB.
P0171 - System Too Lean (Bank 1 Firewall side) The Adaptive Fuel Strategy continuously monitors fuel delivery hardware. The code is set when the adaptive fuel tables reach a rich calibrated limit.

Fuel System:
�· Contaminated fuel injectors
�· Low fuel pressure or running out of fuel (fuel pump, filter, fuel supply line restrictions)
�· Vapor recovery system (VMV)
Induction System:
�· MAF contamination
�· Air leaks between the MAF and throttle body
�· Vacuum leaks
�· PCV system concern
�· Improperly seated engine oil dipstick
EGR System:
�· Leaking gasket
�· Stuck EGR valve
�· Leaking diaphragm or EVR
Base Engine:
�· Exhaust leaks before or near the HO2S
�· Secondary air concern
Powertrain Control System:
�· PCM concern

P0174 - System Too Lean (Bank 2 Radiator side) Same as DTC P0171, but Bank 2. See Possible Causes for DTC P0171

Will work on this list and let you know how what happened...

Thanks Dude!

And you do realize most of the Duratec Maintenance FAQs are here, don't you?

http://www.contour.org/ubbthreads/showflat.php?Cat=&Board=v6maint&Number=958650&page=0&view=collapsed&sb=5&o=7&fpart=1

It could be your sparkplugs plug wires and/or coil pack too. (I had bucking at 2300 rpm 35 mph, cylinder 2 (middle rear) had a carbon track on the wire.)

Latest on my problem:

My mechanic changed the fuel pump (just the pump not the sender assembly, he's been driving the car with a pressure gauge in the gas line, the fuel pressure drops when the car gets wars after 5 or 10 minutes driving.

The guy changed the pump so it's clearly a gas problem. He changed the power wire going to the pump, he changed the "fuel recirculation valve" apparently located in the sender assy.

The fuel pressure is 55psi initially and then dreops down to between 10 and 20psi when the car fails and looses power.

Please help with advise on what may the problem be... are the fuel pumps voltage controlled?

Thanks,
C

I think the fuel regulator is the only fuel line related part that hasn't been changed...

Is there a secondary filter after the main one that may get clogged, is there a diafragm in the regulator or somewhere in the engine that may need cleaning.

What other things can make my fuel pressure line drop?

Assume everything...

Thanks a Million!!! I'm desperate, I've had this problem for more than a month now and the car in the shop for a week...

Will send some of my home brew to the participants on this thread...

Thanks again,
C