OK, so I've resolved the problem with the MAF from the other week, fitted a replacement one.

Now I don't seem to have any boost at all! Car drives OK, revs OK, but the (OEM) boost gauge doesn't go to the + side of 0! It'll run between -7 and 0, but wont go past it, and I'm just not getting any boost at all.

Done an ECU diagnostic, and come up with code 33 (Left hand O2 sensor)

Would this cause the ECU to stop the boost? And if so, how come it's only just started doing it, as I've known that sensor was faulty for quite some time!

If the faulty O2 sensor has nothing to do with the lack of boost, any pointers anyone could give me? I'm almost certain that just after I'd fitted the replacement MAF all was well as I did give it a proper run and didn't seem to notice anything amiss. I defo had boost before the MAF went wrong, not that I'm suggesting that the replacement MAF has anything to do with this problem, but just in-case the faulty MAF has fooked anything else up :D

 

TIA

 

Dave

did you reset the ecu?ecu needs to know there has been a change, take out car battery for an hour or so.

It sounds like one of the turbos has decided to give up (seized)...and it's probably coincidence it happened just after you replaced the AFM...but it won't hurt to try another AFM

 

if that doesn't cure the problem, remove the downpipes from the turbos and see if both turbos can be spinned freely.

 

-Eric

did you reset the ecu?ecu needs to know there has been a change, take out car battery for an hour or so.

Yep, done that this afternoon, but with no joy :(

It sounds like one of the turbos has decided to give up (seized)...and it's probably coincidence it happened just after you replaced the AFM...but it won't hurt to try another AFM

 

if that doesn't cure the problem, remove the downpipes from the turbos and see if both turbos can be spinned freely.

 

-Eric

Thanks Eric.

Not looking good then, mainly as I have no facilities to do that sort of work anymore (the down pipes, not the AFM) and as she's my daily driver I can't afford to be without a car anymore. So it looks like I'll have to sell her for peanuts then!

 

Again, thanks for the help though

 

Dave

It sounds like one of the turbos has decided to give up (seized)...and it's probably coincidence it happened just after you replaced the AFM...but it won't hurt to try another AFM

 

if that doesn't cure the problem, remove the downpipes from the turbos and see if both turbos can be spinned freely.

 

-Eric

 

 

As much as i can see where your coming from, i dont think this is the case. Theres just not enough key symptoms to point towards a shagged turbo.

 

 

Dave, i take it the motor revs freely all the way to the red line, but is simply not boosting, and other than that, theres nothing else out of the ordinary???

 

Do the turbos sound likes theyre "trying" to boost and not getting up any steam? Almost sounds like a huuuuuuuuuuge boost leak to me.

 

Cant see how its anything electrical as the ECU has no control over the boost

As much as i can see where your coming from, i dont think this is the case. Theres just not enough key symptoms to point towards a shagged turbo.

 

 

Dave, i take it the motor revs freely all the way to the red line, but is simply not boosting, and other than that, theres nothing else out of the ordinary???

 

Do the turbos sound likes theyre "trying" to boost and not getting up any steam? Almost sounds like a huuuuuuuuuuge boost leak to me.

 

Cant see how its anything electrical as the ECU has no control over the boost

Hi Nick,

 

Yeah the engine runs OK, as far as I can tell. Gave her plenty on the way home this morning, and apart from the lack of boost, the only other thing out of the ordinary was a distinct vibration throughout the whole car at high revs :confused: I even got a slight 'pttssshhhh' (but only VERY slight)

The ecu can restrict the boost ie safety boost but not to 0 i dont think...hmm do a leak test if no luck disconnect the actuator solenoids to see if the ecu is holding back the boost at all, im not an expert but at least give it a go i would.

 

also check the exhausts and see if either is pushing out less pressure than the other. if one seems as tho its blocked OH DEAR......

 

hopefully just a big leak, fingers crossed.

Whats OH DEAR? If one seems blocked what does that mean? Ta

If its blocked then i think that side turbo would be siezed as its not spinning and exhaust gases cannot flow. u get me?

I getcha. Thanks. That is bad news if thats the case!

But surly if it was blocked to that extent, then the engine would stall, or at least run very rough?!

But my engine is running fine.

But surly if it was blocked to that extent, then the engine would stall, or at least run very rough?!

But my engine is running fine.

i agree

exhaust gas should still be able to flow but not a lot, trust me if it was a siezed turbo you would know about it. im not a pro but its just logic. i doubt your turbo is pooped or you wouldnt be able to rev it like u can, u must have a bigleak, a hose detached or intercooler pooped check them all when you can. and do that leak test.

yeah the engine would run like a 1 legged donkey with a siezed turbo.

 

at least one side of the engine anyway. youd have too much back pressure like jamming a potatoe in the exhaust, probably would stall your right.

Sounds like its on safety boost and your oem gauge is rubbish.

 

Resetting the ecu might require the battery being out for more than an hour. And once disconnected hold down the brake pedal for 5 sec to drain any power left in the caps on the boards.

That could be it. oh look im subscribed now ;)

And I updated me Avatar!

i cant get a small enough pic of anything.... will have to sort out me photoshop and reduce some ;)

I just removed the Z badge :)

 

Has to be gif and 100x100 pixels or smaller

removed the z badge and was left with 2 pin holes?

No using photoshop!

 

Although I will do it for real soon!

cool cool.

>> The ecu can restrict the boost ie safety boost but not to 0 i dont think

 

it can, if programmed to do so...

but a boost-cut by the ecu is very violent...almost like hitting the brakes

 

>> yeah the engine would run like a 1 legged donkey with a siezed turbo.

 

you would think so, but it won't.

I have seen several Zeds with one or 2 seized turbos and they all ran fine, just lack of boost.

I also know someone that bought a Zed with a seized turbo and wasn't told about it

He drove it around for years like that, thinking it was normal, because the car drove fine..

apparently one of my turbos was seized - only found out while they were being refurbished, and i hadnt noticed any difference while driving at all, maybe a little slower to spool up, but i was obtaining 14psi with no problems.

Amongst the 3 or 4 turbo faliures I've had, one has been a seized turbo.

 

As eric says the symptoms are car runs perfectly well, no bad stuff at all, but maximum boost is 0psi and there is a lack of performance. I also hoped an intercooler pipe had jumped off btw ;) but alas no, turbo was mashed.