Not Terrano but still Nissan - 2.0 turbo diesel problem

[Muckypup]

Hi Guys,
my other car is a Nissan Primera 2.0 td, a cracking car but it has a slight issue.
When the turbo is spinning it has loads of power and pulls like a train, but when its not the engine has a quite bad judder/shudder/kangaroo syndrome.
For exmple, 30mph in 4th gear the shudder will start and gets so bad you have to press the clutch to let the engine chill out. The turbo is not running at that speed so cruising smoothly requires 3rd. Normally this would not be the case and you would be able to cruise and pull from 30 in 4th
My mate unplugged the harness from the MAF on saturday and that seemed to help a little, which made me think about having a look at the MAF.

Does anyone know if I can service it, or if its much to replace?

Cheers!

 

[ShaunAFC]

Have you tried cleaning the connections to the MAF etc?

 

[clivvy]

clean the maf wire...be careful, gentle, and use electrical contact cleaner.

 

[Muckypup]

So same sort of thing that I did with the petrol Maverick?
Its a different system tho aint it, this being a round jobby in the air pipe... do they work in the same way? :thumb2

 

[11redrex]

same thing, metal tag or tags which tell the cpu what the air temperature is so it can adjust the amount of fuel. Just be very careful ! Contact cleaner and cotton buds.

 

[Muckypup]

Excellent, thanks for that. Exactly what I did with the Mav :thumbs

 

[Muckypup]

Absolutely nothing to do with the MAF. Cleaned it made no difference and makes no difference if its plugged in or not...

Plugged it into computer at a mates garage as the ecu light comes on and off intermittently. Only fault showing up is the V.S.S (Vehicle speed sensor)
This is a little sensor located at the rear of the engine on top of the gear box, which I believe tell the speedo your speed...

Please excuse my ignorance, but how can that affect how the engine runs?

Its £140 plus vat and my speedo reads fine so would be a bit of a waste to buy one and it make no difference to the problem.

To go over it again, the engine kangaroos when turbo not running, turbo running its fine. Could a dodgy V.S.S cause this?

Cheers guys! :thumb2

 

[clivvy]

if its signal based, perhaps the actual engine speed determined byu the sensor sends a signal to the ecu for fuel injection, timing etc??

sorry, i dont actually know, just speculating!

 

[Muckypup]

would make sense I suppose :nenau

 

[Hilltop]

Kangaroos !!

Kangaroos when the turbo is not running !! Why is the turbo not running ?? how do you stop the turbo running, I'm just confused.


Bob (gw0fje)




.

 

[solarman216]

If you unplug the MAF with the engine idling it would normally stop, indicating the MAF is doing something, Rick

 

[Muckypup]

Nope, unplug the maf no difference. Could that be an issue? My diagnostics guy didnt think so, he unplugged it and said try it for a while see if theres any difference
There wasnt which is why i'm looking at the V.S.S, it was the only thing showing up on the diagnostics. Reset the ECU and the V.S.S fault shows up immediately


HILLTOP - When I refer to the turbo not running I mean in the LAG stage, before approx 2000 revs when the boost kicks in. Only superchargers give you boost pre-2000rpm
Or so is my understanding...

 

[4wheel]

Primera

Suggestion.Disconnect the V.S.S and see if there is any difference.If not then perhaps ? Another thought is that if the faulty V.S.S. is looped back to the CPU it could disrupt the signal for low speed fuel mixture.Then again I have no idea what I am talking about .:nenau

 

[solarman216]

If unplugging makes no difference, then it is doing nothing, if it is doing nothing so why is it there? simple, Rick

 

[rustic]

If unplugging makes no difference, then it is doing nothing, if it is doing nothing so why is it there? simple, Rick

Since I don't have a MAF and also don't know what I'm talking about either....
but recalling the Terrano problems, if you unplug the MAF and there is no change then the problem is the MAF!

Logic according to Spock....
Live long and prosper...:lol

 

[rustic]

Since we all know F....all, I bet we could work together and pilot a Terrano to the moon. ( Probably the first landing ever)...

Somehow we seem to help each other and solve the problems.

That's another reason I like this site.

 

[Muckypup]

Many minds attacking the same problem stand a good chance of solving it... one mind often stays focused on the wrong thing leading to no solution! :thumbs

I genuinely have no idea when it comes to modern ecu controlled engines, gimme an old motor any day! All I know is most of the guys I used to think were whizzes with engines are no longer in the business as modern engines were not their thing. Now a days it seems you have to be a computer programmer to go anywhere near them!

I'm quite concerned about the MAF, as I totally understand what your saying Rick, it didnt make sense to me either. But the other thing I dont understand is that there was nothing showing up on the diagnostics for the MAF...

I think i'm gonna have to just buy a used v.s.s. & a used m.a.f, swap them and then see if there is any difference, cheers again!