1.9 dci lacking low down torque/power, RR graph included

[sburrell93]

Well, this isn't a clio, but there's a good knowledge base on here so thought it was worth asking anyway.

Its a vauxhall vivaro van, but I believe it's the same engine as in the laguna dci, 100hp one.

Basically it has no low down torque at all. It almost drives like a petrol. So far we have tried changing the MAF sensor, checked/cleaned EGR valve and changed the boost solenoid to no avail.

Anyway here's the RR graph

As you can see the curves look nothing like a diesel should. The final blue run was with the boost solenoid disconnected and the two vacuum pipes connected together. Also ignore the lines drawn on to show what a diesel graph should look like.

Does anyone have any ideas what this could be? My only thoughts is that the wastegate actuator isn't set up properly.

 

[Dan@SJM]

Smoke test it. Bet there's a vacuum leak.

 

[R3k1355]

It's making shitty boost for a diesel, it's not on full boost till 3.2k - what the f**k is up with that.

Gotta have a big issue with boost/vac somewhere, should be well on song before then.

 

[sburrell93]

Smoke test it. Bet there's a vacuum leak.

It's making shitty boost for a diesel, it's not on full boost till 3.2k - what the f**k is up with that.

Gotta have a big issue with boost/vac somewhere, should be well on song before then.

It was tested to see if it was holding a vacuum when it was getting it's RR runs. Holds a vacuum fine apparently (I wasn't there at the time, but my dad was and it's his van).

And the smoke from it is surprisingly minimal. I thought it seemed short on boost though tbh. Its making 1 bar according to the live data I can get but I can't find any figures on what its supposed to be.

 

[bashracing]

Air flow restriction in inlet tract or exhaust (suffer cation) ?

 

[Dan@SJM]

Not that kind of smoke test you put a machine on the inlet and let it do its thing. Then if there's a leak it'll start pissing smoke out.

 

[sburrell93]

Not that kind of smoke test :smile: you put a machine on the inlet and let it do its thing. Then if there's a leak it'll start pissing smoke out.

May be having a r****d moment here but how would putting something on the inlet reach the vacuum lines? I thought the vacuum setup on a diesel just came from the vac pump?

 

[Dan@SJM]

As its all linked via solenoids etc for boost control.

 

[Rickwood]

Try simple things first.
Is the actuator moving freely?
Is the map sensor clogged up?
Egr stuck open?
Silly little things like that could cause it

 

[Daniel]

Map sensors are quite common to fail on them.

 

[sburrell93]

Actuator moves fine yeah. EGR has also been cleaned out, tried disconnected etc so that's ruled out as well.

Not sure if he's tried a different map sensor in it, but the live data off it doesn't point towards it being dodgy

 

[Rickwood]

For the sake of one bolt (normally) just pull the map sensor out and make sure its not clogged up