Engine speed sensor?

[philj]

Just plugged the urs4 into the computer and its come up with the engine speed sensor giving a dodgy signal, and thus it thinks it is over boosting, so seems to have put itself in a limp home mode with only 1.7 bar and 9mpg? Although the digital boost guage read 2 bar before, we've just made a twin 2.5" straight through stainless system, went out, put my foot down and it was quick, then it was like it cut the boost down straight away and its been a bit sluggish since? Computer said engine speed sensor, so, where is it for a start?

Cheers

As below, now changed the sensor and its violently cutting the fuel/ignition?

[haaran]

Were you running the engine whilst checking the codes?
If not then that will give the engine speed sensor fault I think.

[spink]

***edit**** sorry i was getting my sensors mixed up
no thats the cam position sensor
***edit**** sorry i was getting my sensors mixed up

engine speed sensor(g28) can be found down on the bellhousing area on the passenger side of the engine,its actually bolted to an alloy block which is itself bolted to the block.I changed one on a car lastweek actually as it was giving no signal and causing massive overboost problems,which i have a feeling was the cause of the failure of the previous engine in the car(rod came through block on a non chipped/low mileage/fsh car)

[philj]

Lovely, I've just had a look and there seems to be 2 there? Do both need doing?

[spink]

Lovely, I've just had a look and there seems to be 2 there? Do both need doing?

yes there are 2,just one needs changing,the other is for the timing pin.Pretty sure the g28 has a black plug on the end but i would need to check again to be sure on that

[Gazjen]

You need to change the one that's looking at the ring gear on the flywheel, The one closest the gearbox

[philj]

Cheers, looked it up on etka, got another this afternoon, changed it over, now before it wasn't cutting the fuel/ignition, changed it for a new part (non genuine) and now soon as it gets to 1.5/1.6 bar the overboost cuts in and jerks violently! Pain in the ****.

Done a bit of digging, can anyone confirm the differences in these part numbers?

I've take off an 034 905 381A, but replaced it with a part that does 078 905 381 A, which seems to be for the AAH and ABC engine codes?

So I assume I've been given the wrong one...

[philj]

Then, after ringing around, it seems the only difference between the above numbers, and the ignition timing sensor is the length of the wires, as the pattern part replaces all the options.

Hoepfully I've just had a random duff one...

Anyone got any ideas?

[philj]

Well after a bit more digging on here, theres a good chance that speed sensor code was only brought up due to check it without the engine running!

There was another overboost code, but before I changed the sensor, it didnt cut it violently, just felt a bit sluggish...

If anyones got any ideas it would be much appreciated.

[yodaboy]

The sensors are magnetised and pick up all kind of crap....gave mine a good clean last week

[Smiley]

Are you shure you have no silly leak or a situation with the WGFV?

[Smiley]

Aah, and the ambient pressure sensor may have readings way out..
You asked about ideas..

[spink]

Well after a bit more digging on here, theres a good chance that speed sensor code was only brought up due to check it without the engine running!

There was another overboost code, but before I changed the sensor, it didnt cut it violently, just felt a bit sluggish...

If anyones got any ideas it would be much appreciated.

***edit**** sorry i was getting my sensors mixed up,i was wrong
no mate,its the cam position sensor that gives a code if the engine isn't running
***edit**** sorry i was getting my sensors mixed up,i was wrong


the overboost code was quite likely caused by the engine speed sensor(g28) playing up,certainly was on the car i was working on last week.

[philj]

Yeah I saw that after I posted, just thinking that may have been the code, I just saw speed sensor, and got on the phone, need to check it tomorrow.

Will have a quick rundown...

When I picked it up, it was doing it straight away, I changed the recirc valve for a forge one and it made it a fair bit better, but you could still feel it holding back but it wasn't violently cutting out. Did the exhaust, first test drive, put my foot down in first, shot up to 2 bar, then cut but softly. So went back, plugged it into the computer, and it said overboost and speed sensor.

Changed the speed sensor, and now its cutting out violently almost kangeroo'ing!

I've had a look about, and everyone suggests checking for boost leaks which I'll do tomorrow, but if theres anything else I can do to check/rule out? I've got another speed sensor on the way tomorrow, in case the new one was faulty. Will check the codes again tomorrow.

A friend of mine is due to take the car and I wanted to enjoy this lovely 5 cylinder note before I hand it over!

http://www.youtube.com/watch?v=qiiIR3AhopU

[Gazjen]

G28 does Sometimes show up when pulling codes if the engine isn't running but just test with it at idle to check.