Hello,

got a new problem with my Saff.

When I was driving yesterday, it starts to not rev past 4000. At the beginning just sometimes, and now it wont rev past 4k at all.

At the same time it got another problem, the engine wont start witout to push the pedal a bit.
Changed the intake temp sensor and checked the baseidle with iscv unplugged, around 900rpm

Has someone an idea or a list what causes the ecu in limpmode ( it`s a P8)



Thanks

 

Could be someting whit tps sensor, as you say you have to push the pedal to start it. Not sure if that could cause a limpmode

 

Lambda sensor can cause it

 

check all sensors

Throttle Position Sensor
Crank Sensor
Phase Sensor

 

Or get the fault codes read. Somebody with a star-tester or a led-tester can tell you what's wrong.

 

Thanks for the relpys!

Went out for a drive today and everything seems fine, no limp and starts as it should...

Can a faulty tps cause the ecu go to limp mode?

 

You can reset your ecu like this:
http://www.grahamgoode.com/cgi-bin/f...stion=question

 

I think I dont have that button, cos it is fitted in a saff?!?

 

Ok, it is there again, went in limp mode but starts ok this time. So any sensor must be out.

I know that the brown and the blue sensor can cause the limp,maybe the lambda and tps and what else?!?

 

The easiest way, is to go to a Ford dealer, and read out diagnostic.
Here is some information about sensor testing:
http://www.cannell.co.uk/Ford_Worksh...sis%20Info.pdf

 

Thanks for that, will give it a try as the local ford dealer cant read out the diagnostic...

Was there with my escos a few years back, and they cant help me.
If I found the problem I will post what was wrong!

 

I work for Ford myself, and of course this is old stuff, but they would normaly have a fault code reader, so it shouldn`t be a problem. Often it is because the mechanics are to young and have never use it hehe.

Cheers

 

Got some news!

But no good ones

Turns out it is not limp mode, cos this revcut is now at 3000.
And when I hit the 3000 on boost, the engine wont rev past that and goes out. There is no power at all and I am just rolling a few seconds and then the engine will pick up again.

It seems also to be some kind of temp related, cos after a few miles of driving everything seems ok!

Strange things...

 

You are sure it dosen`t blow out ignition or get to less fuel?

 

Well, sure am I not

Was measuring all the sensor and everyone but the TPS was fine (while pressing the pedal the ohms jump a bit up and down), so changed the TPS for an old one that was flying around. Will see what happens.

 

While we are talking about LOS on P8, here is some info for you:

By far the most common cause for running problems on a P8 managed vehicle is the special ‘limp home’ mode enabling. This will prevent the vehicle revving past 4000rpm both at idle and under load once the engine is hot. When this safety feature is activated it will not rev past 4000rpm and you will experience what feels like a misfire that you cannot rev through.

The limp home feature is designed to protect the engine from damage, whilst still allowing the vehicle to be driven home, avoiding the unpleasant experience of being left at the side of the road. The vehicle will only go into limp home mode when it detects an error condition, this error can be caused by a number of things; such as sensors having failed, sensors plugged in incorrectly, poor earths to the ECU, lambda sensor being unplugged (or fuse failure) etc.

A large number of chip retailers use a facility to turn this limp home feature off within the chip, including virtually all chip suppliers using Pectel products. This is normally done either for competition vehicles or to avoid dealing with running problems encountered after the sale of a chip has increased engine power and highlighted other shortcomings, thus limiting the after sales support required. A sad but true fact.

However, as I’m sure you can appreciate, running without this feature offers no protection to your engine in the event of a sensor failure or other potentially damaging condition. We have always prided ourselves on ensuring reliability and safety for your engine and as such, use this feature within our chips, in fact, on our latest software calibrations we have enhanced the system even further. If you are experiencing running problems of this nature then we recommend all sensors are checked for condition and correct operation, starting with the lambda sensor and associated circuits as this is the most common cause of the system being enabled.

 

You can test all the sensors with a multimeter i dont see why you would waste time guessing.?

Get a wiring diagram off the net and check the voltage and resistance in the TPS and compare it to what it should be.

Chances are the TPS is closing too much and causing the problem try opening the throttle butterfly with the cable a little then start it up and see if the error happens. You should set this sensor with a multimeter at closed throttle and make sure it reads fully to full throttle with no breaks.

you can test each sensor in similar ways. If you need more help how then i have written many tech threads just need to know where to look.

Regards
Jano

 

Agree, you got all sensor information from me up in this tread, only thing missing is 3bar map

 

As written in a post above, had checked the sensors and everyone but the tps was spot on.

Changed that but it seems the problem is still there. Only had time for a short drive.

So the brown and blue sensor are ok. the phase and the cranksensor are ok, lambda too. So I think there is not much more left to check?!?


edit: MAP is still there to ckeck, but need a pump to test.

 

Have you check your engine wiring, from sensors to ecu, the big plugs on "torpedo" wall is a nown problem