Thread: D2 TD5 sluggish below 1900 RPM when hot

Could it be the fuel pump failing because the fuel in the tank has heated due to the return fuel?

Trout,

Hard to say but over 1900 rpm it goes like a cut cat. Doesn't seem to be fuel related over that figure.

That being said I believe that fuel is being restricted until the turbo cuts in..

?

Originally Posted by eckolsim

known fault codes: Fuel sensor high and occasionally P1884 I think.
Fuel temp sometimes reads below zero degrees when cold on Hawkeye.

If that code keeps coming back replace the FT sensor in the FPR cos on high FT input the ECU reduces fuelling and that -0 reading makes it more suspect, get genuine or at least a bosch one cos it's not very expensive(ERR2081)... also make sure that the wastegate is not sticking

Check the fuel temp sensor wiring, might be chaffing on something or broken.

Quick update...

Fuel temp sensor wiring was damaged along with a few other areas.
Replaced the engine harness with no change in the power loss issue. Confirmed that Fuel Temp sensor was shot however.

Replaced fuel sensor this morning and drove to work (30 mins). No sign of power loss issue. Not yet ready to call it fixed but looking promising. Will advise after a couple of days of driving.

OK. Claiming victory here. More around town driving and the car is driving as it should.
It has been a 2 year battle and am happy to see the end of it.

Add Fuel temp sensor to the known causes for dangerously sluggish behaviour below 1900 RPM.

Thanks Guys.

Howdy

Apologies for the post hijack, I've been trawling AULRO for posts about sluggish takeoff and this seems to be as close as it gets to my experience. I realise there is a long list of potential culprits for loss of power issues, but most of them seem to come up with a cold start, or after leaving the car idle for a few days, or some other scenario which I do not relate to. My purse is tight so I would prefer not to go and implement solutions to problems I don't have.

Symptoms:

'Intermittent' loss of power below 1900 revs over the past 6 weeks. No throttle response other than a very slow creep up, whether my foot is on the floor or leaning on the throttle. Then 1900 comes around and off she goes.

It started as a one off occurrence once a week, then gradually happened repeatedly during some journeys. It has mostly happened in first gear, but a couple of weeks ago when driving around the Mornington peninsula this happened in 2nd and 3rd, repeatedly and relentlessly over the course of one drive - but again only when revving up from ~1500 and up to 1900. Most days it does not happen at all, but I live in inner Melbourne and mostly do short drives. The reason this post is ringing familiar is I feel this tends to happen after extended periods of driving, whether in one slug or in quick succession... when the fuel return has warmed up the tank?

EGT registers between 200 and 350 most of the time, goes up to 450 when trying to get up to speed on the freeway with a mild incline. Unfortunately do not have a Nanocom - I would definitely buy one if the car didn't already have 300,000+ on the dial when I got it. Perhaps a false economy...

FYI the cam/crankshaft alignment was done in the last 3 years by the previous owner.

Took the car to Mornington Prestige for a checkup this week, they picked up on a very subpar reading coming from the MAF and reckon this is the culprit. No error codes that they can otherwise point a finger at. Unfortunately they are booked until February - as is everyone else in Melbourne - and I am pretty keen to get this sorted before then.

Tried unplugging the MAF yesterday - was a bit skungy in the multiplug socket so sprayed some contact cleaner but left it unplugged to see if anything changes. I feel the car *may* have a bit more power generally speaking, but sure enough the sluggishness cropped up halfway through the day, briefly. Will plug back in tomorrow and look out for any changes post-clean.

Back to this thread: would it be safe for the engine to drive for a couple of weeks with the fuel temp sensor multiplug removed? I know the ECU reverts to predetermined air flow values when the MAF is disconnected, but can't find information about the FTS. I feel this is the only way to cross this option out, given how unreliably occasional the issue is. I would have to give the car a good running over several days without the loss of power to feel that I am onto something, as opposed to having a couple of lucky days.

Follow up question: what is the easiest way to unplug the AFS multiplug? I struggled to get the MAF multiplug loosened, and that was with front and centre view. The FTS is a bit of a reach even for my dainty fingers.

Also of importance: the mechanics told me there was no risk of further harm in driving the car under the current conditions - but should get this sorted whenever I can. How does this ring? I have been stuck in Melbourne for well too long, and was hoping to get some open road over the holiday period. Should I start managing my expectations? ...

Any other experiences/recommendations very much welcome, and merry xmas to all.

Cheers

t

No experience with a faulty fuel temp sensor, but yes if you disconnect it will also revert to a default value.

With the Td5 you can pretty much disconnect any instrument used by the ECM for air/fuel measurement and it will assume it has failed and default to predetermined values. If performance improves you often have found the culprit if it is a sensor that has faulted.