benjipage

hi there can anyone point me in the right direction please, my 2001 2.5 v6 mondeo has lost power and wont rev above 3-3500 rpm.mil light is on. i have changed plugs,leads,imrc,lambdas,rear cat,fuel filter,air filter and cleaned secondaries but still no better. i tried redex and stp petrol treatment. it keeps blowing the engine management fuse as well. and i disconnected the speed sensor at back of gearbox but nothing seems to work.i don't want to scrap it as i love my car but this is driving me nuts

Bungle

Is it misfiring or firing clean but won't rev? How's the maf and the coil pack?

benjipage

hi, it fires cleanly then splutters at 3-3500. i replaced the maf sensor but no change. taking the car to collage today so will get coilpack tested.

Bungle

Any joy? Re my question does it misfire at 3k or just sck air and bog out / die?

benjipage

coil pack seems ok, cleaned out iacv and no more mil lamp so far but still spluttering at 3500 maybe its an air leak somewhere.seems to rev up to 5-6 k when not moving but won't hit limiter. has a pending code p0174 pending but no mil lamp.was thinking what about charcoal canister

oldford

Pending codes do not set the MIL (yet).
Drive around for 2 more days and it will become an active fault code with MIL on.

P0174 - Fuel system lean Bank 2.
Air leak is a likely cause. Could be charcoal canister if that is connected to bank 2.

Do you have access to live data? What are the Long Term Fuel Trims?
Just to check that bank 1 is also lean, but just before the DTC limit.

benjipage

i will check on the fuel trims tomorrow, also should the throttle be at 17.6 % on tickover.

oldford

Is the throttle percentage absolute or relative?
Absolute shows a percentage of the full scale analog signal, might be right.
Relative shows the opening relative to full closed, then it would be a lot.

benjipage

not sure on throttle but just bought a new fuel pump,sender,throttle body and tps. found a split hose by t piece under throttle body.fixed that but still p0171+p0174 bank 1+2 running lean. wheres the best place to get new uim+lim gaskets as i may as well replace then when i clean the secondaries.i have torque lite obd for android with bluetooth obd plug in so just learning to read it properly.

oldford

Did you clear the codes after fixing the split hose?
Warning: do it with a warm engine, so the ecu may relearn immediately.

benjipage

once i fixed the hose the mil went out.but still getting pending fault of p0171+p0174, to reset the ecu is it better to pull out a fuse or disconnect the battery. what number fuse is it?. why on a warm engine?. can a faulty speed sensor on gearbox cause this problem?.

oldford

Fault codes are better cleared with the scanner.
Clearing them will also clear any learned values.
If there is still a mixture problem, the engine will relearn immediately when warm.

Faulty speed sensor cannot cause this problem.

If the MIL goes out, then the fault codes are no longer active. The MIL only goes on when they were active codes (in service 3), but they can be duplicated as pending codes (in service 7). Service 3 codes are kept for at least 40 more engine starts.

benjipage

ok thanks, which fuse is it to relearn the ecu.are the throttle bodies known to play up or the tps.

benjipage

hi, thanks for the help, fitted new fuel pump from ebay and job done. no dtc back to full power. i ran a magnet around the tank and come up with metal fillings.(not much but)cleared out now. now i've got a spare throttle body but don't know whether to keep it as a spare or what