2008 1.8 Tdci Ford Focus Limp Home

[M@tt 77]

The missus' Ford Focus has started playing up. It appears to be going into limp home mode whenever you give it any beans. It basically wont go above about 2.5k revs when under load.

 

When not under load i.e. clutch to floor and loads of gas pedal it revs fine

 

Its like hitting a bit of a brick wall, I've used my scan tool on it but there's no codes at all present.

 

Usual suspects are MAF sensor, I've unplugged it but it made no difference.

 

My scan tool does live readings but I'm unsure what are/aren't acceptable values for the various sensors so it's a bit fruitless trying to stare at them whilst I take it for a spin up the road

 

Any ford boys or mechanics on here with any ideas?

 

Ta

[Tom Fenton 1,542]

I've had a MAF crap out before on a late diesel Mondeo and not throw a code, however it was just gutless, it would rev ok.

Your fault to me sounds MAP sensor ish. Can you see values for MAP on your scanning thing?

[205kenny 7]

Sound like a boost leak or maybe map sensor, check map/boost reading on live data.

 

My brothers car did the same thing and turned out to be a split boost pipe.

[farmer 328 1 Cars]

i had no ends of trouble with my vaxhall with EGR valves

[TT205 42]

I've had this on multiple occasions on a Saab TDi almost always it's the EGR valve, but on one occasion was an electrical fault (bad earth) causing it to go in to limp mode

You can kick it out of limp home by intentionally stalling it or when running turn ignition off and back on and re-starting very quickly to confuse it

With my EGR faults (I've had three now) twice was the electrical side of the valve and just gave symptoms like yours, once was mechanical (gross carbon build up) and it just died - temporary fix was to repeatedly hit the valve with a mallet while turning the engine over

[TT205 42]

So what was the problem Matt?

[Rich_p 23]

An old work mate of mine had a similar issue. It was a tiny pipe within the boost system somewhere had split at the end and come loose. It was trimmed and re fitted and it did it again a few months later.

[johniban 59 1 Cars]

get someone to rev the car and see if the turbo actuator is working, ie the rod moving, if you have use to a mitivac you can put it on the end of the actuator and pump it to see if the diaphragm is leaking.

Or if the waste-gate is jammed or sticking.

Does sound like a boosting issue due to it only happening under load but it shouldn't really go into limp mode,

 

I'm unsure of the workings of the boost system on them engines, but usually they have electronic solenoids to control the turbo actuator and you wont see it working on live parameter readings as you will see the engine ecu asking for boost say 1200 mili bars and if there is a leak somewhere or the solenoid is bust it just wont work, but also wont give any fault codes.

Sometimes if it has an air flow meter fitted it will come up with an air flow fault like to air metered to high or to less.

 

You could always pull the vacuum pipe off the turbo actuator and drive it CAREFULLY, not foot flat to the floor, and see if its boosts up fine, just to rule out the turbo unit itself.

id whip off the air filter piping and make sure the turbo impella is free and has no excessive movement in it too.

[johniban 59 1 Cars]

An old work mate of mine had a similar issue. It was a tiny pipe within the boost system somewhere had split at the end and come loose. It was trimmed and re fitted and it did it again a few months later.

citroen c5s and xsaras have this issue, the actuator vacuum pipe splits, usually they are cut off and put back on.

[johniban 59 1 Cars]

I've had this on multiple occasions on a Saab TDi almost always it's the EGR valve, but on one occasion was an electrical fault (bad earth) causing it to go in to limp mode

You can kick it out of limp home by intentionally stalling it or when running turn ignition off and back on and re-starting very quickly to confuse it

With my EGR faults (I've had three now) twice was the electrical side of the valve and just gave symptoms like yours, once was mechanical (gross carbon build up) and it just died - temporary fix was to repeatedly hit the valve with a mallet while turning the engine over

 

EGR systems are a killer these days, especially wiring problems, as later citroen/peugeots engines like c4 picasso ( witch we have ALOT of problems with wiring!) the EGR and Airflow meter share the same feed, so we can see fault codes like air flow to metered ect, people usually would just replace the air flow meter as most garages that we get sent cars from do at a costly guess,

Then when it comes to us we check it for feeds to find it has none, and you find a broken wire up near the egr valve

[205wrc 16]

I've seen this happen on Mondeo's. What mileage has she done??

At around 60k miles the injectors need re-programming. We had this happen to one of our customers. At first she was complaining of lack of power sometimes, then it became more frequent until one day the car refused to start. We had a word with the local Ford main dealer and the first thing they asked was "How much mileage?".........."injectors need re-programming".

We re-programmed the injectors with a Snap-On code reader and there has'nt been a problem with it since......

[205wrc 16]

We had another one in today......58 plate Focus. Wouldn't rev above 2000 - 2500 under load. On the fault code reader, it threw up "Diesel Additive Tank Low Level". That wouldn't cause the lack of power, but the symptoms of failing to rev, and no power is pointing towards a blocked Cat......

[M@tt 77]

cheers for the replies chaps

 

we've still not sorted it yet

 

Baby no2 arrived 1 month early and has been causing us a few headaches so I haven't really had time to look at it plus we're moving house next week as well!!

 

its done about 60k I think

 

how can the injectors need reprogramming? what do they change on them?

 

EDIT> according to this her 2008 1.8 tdci doesn't have injector programming (or at least not listed here)

http://www.autodiagnos.com/sites/default/files/ford_injector_programming_tdci_ad.pdf

Edited December 13, 2012 by M@tt

[205wrc 16]

The injectors are coded to the ECU and the codes can get lost. I'd go down the blocked cat route first though as it's the cheapest test. Un-bolt the cat from the system - downpipe off the manifold and try driving it. Noisy I know, but it will eliminate it.