Limp mode then cuts out! :(

[redmans]

Good morning all,

New to all of this so go easy on me!

Few months back had a lot of issues with my Signum, going into limp mode turned out to be the Throttle Body was shot (So i've been told, haven't got a clue when it comes to cars). This was replaced, £340 later, she was driving lovely!

Then.....

Driving to work on Friday morning, on the M4, car with spanner then goes into limp mode, managed to pull over after making my way from the fast lane . As soon as the car come to a stop, it cut out. I did notice though that when I was about to stop, foot on the clutch and the revvs dropped to about 500, stayed there about 5 seconds and cut out.

Got towed to a garage and they said they haven't got a clue, it will have to go to Vauxhalls. Somethings telling me that will be an expensive trip. They have given me the following codes though:

P0070 Ambient Air Temp Sensor malfunction
P0638 Electronic throttle position sensor circuit high input
P1614 Immobiliser wrong signal received
P1616 Steering column module wrong environment identifier

Even though they have these codes, they say they haven't got a clue, and the throttle body that was put on in September 2011 looks brand new.

Didn't know if anyone else has had the same issue before and could help before I take it to the stealers!

Just noticed how much I have been going on and haven't even mentioned the car. It's a 05 plate Signum Elite 2.0DTI covered 115000 miles.

Just remembered that the past few weeks a few times the revvs at idle would go from about 900 to 500 and up and down until I shut it off. No EML but as soon as i turned her off and back on not an issue. Was told that this could be an issue with the EGR valve, but the garage took a look and said that it's full of gunk but is still moving freely so shouldn't cause an issue. Black smoke from the back when I boot it, but apart from that nothing out of the ordanary for a Diesel.

Any help would be great, it's driving me mad not having a car and trying to rely on public transport!

Thanks,

Sam

[Critch]

Need some live readings to help you out.

But it could that the TPS ( throttle) is sending a bad signal so therefore can't work out if it's on part throttle/ no throttle etc

But as said you need live readings to see what's happening

[Critch]

Need some live readings to help you out.

But it could that the TPS ( throttle) is sending a bad signal so therefore can't work out if it's on part throttle/ no throttle etc

But as said you need live readings to see what's happening

[redmans]

Okay, so picked the car up last night, she drove fine from the garage. The garage said this is a strange one as he cannot find the fault at all.
The engine only cut out on him when he disconnected the throttle body. The problem seems now that the engine will run fine but mor often than not at ide the revvs will drop to 500 then back to 900 until we shut the car off. The garage also reported that this is now happening at 2700rpm, it will hunt then as well. No EML or car with a spanner now, really doing my head in.

He said something about the MAF sensor, tried a new one as the readings were all to pot (Haven't got the exact readings) but soething to do with it was saying that there was more air going in than was actually present and the ECU and throttle body stop asking for the readings from the MAF when it starts hunting at both idle and 2700rpm.

As said, tried a new MAF, readings looked good but problem still there and the car with a spanner showed up, stating fault with the EGR valve, They have said this cannot be right as the valve is dirty but is moving freely, not sticking what so ever, he tried the new MAF on his 2.0DTI Vectra and it threw up the same fault with his EGR valve, even though he dosen't have an issue with his car.

They are now telling me that this is an issue with the fuel pump! AARRGGHHH!!!! £1400 apparently! If it was the fuel pump the car woudn't drive fine or start would it? Can't see how that it linked in with the hunting.

Checked all pipes and vac pipes, all fine.

Starting to pull my hair out now, might just throw the towel in and get shot of her!

[Critch]

Think time to go else where.

If the egr is gunked up why not clean it?
What's to say it not sticking partially.

What type of tests have the garage performed or have they mearly plugged computer in and said can't find fault?

If their scoping and use line graphing data something will be playing up.

[Critch]

Double

[redmans]

From what I'm feeling, they are only doing things by their computer and "Knowledge".

Sometime this weekend I will try and ckean out the EGR valve and see where that get's us. Just messaged him now and he said that he has sent the MAF back so the orginal is now back on my siggy but the one he used was a Fast Parts one :O! I've seen on here only to use VX ones as others can cause more problems than actually exist!

Any idea on the price of a MAF sensor from VX?

Thanks for the replys Critch, your a star!

[Critch]

Before you throw money at parts I'd go to garage with someone able to use and interperet an oscilloscope.

Things like MAF readings etc can be performed within a couple of minutes and will confirm maf ok or not.

For time being You could try cutting a coke can (other brands will also be fine) and cover egr whole on the block.

Tie the egr valve up out of the way nice and securely so won't fall.
Leaving it connected so ecu still thinks its working. And see if that has any help

[Critch]

Double post

[redmans]

Thanks Critch,

Will have a look this afternoon and give it a good blast and let you know what goes on. How do I attach the can to the hole? Sounds daft but not very mechanically minded!