M35 Stagea with VQ25det Boost issue breaking my heart

[Pelican86]

Please help me! My 2001 M35 Stagea ARX fitted with the VQ25DEt (all standard aside from a pod filter) is missing badly, pulling back, jerking when coming on boost and you can smell it if you try pushing through it. It's kinda similar to hitting fuel cut.

 

Yet At idle and normal driving it doesn't miss a beat??

 

I've been told it could be wastegate issue (anyone know an appropriate replacement wastegate?) Or ignition related  or even intake related however I've checked all hoses and they seem ok. I've done 55000kms in it myself and it hasn't missed a beat til now.

PLEASE HELP,  and thanks everyone, the info supplied on here is great.

[Leroy Peterson]

Who told you it could be a waste gate issue?
If waste gate wasn't working properly it would be making too much boost and would pull pretty hard... Not sure it would cut out though.
What do you smell? Fuel?
Does it drive OK off boost?

[GTSBoy]

Fuel pump.  AFM.  FPR.  Dirty injector.  Blocked fuel filter.  These are the first things to check.  Same as in the 500000000000 other threads that start this way.

[Pelican86]

3 hours ago, Leroy Peterson said:

Who told you it could be a waste gate issue?
If waste gate wasn't working properly it would be making too much boost and would pull pretty hard... Not sure it would cut out though.
What do you smell? Fuel?
Does it drive OK off boost?

Smells like rotten eggs. My Soarer used to smell the same when I'd been flogging it. It's driving fine under light acceleration. The bloke at autobarn advised potential wastegate issue and I read this last night so makes sense. 

If you've driven a turbocharged engine before, you'll easily understand the difference between an engine that is engaging the turbo and one that is not working properly. When you apply throttle pressure to the engine and the turbo does not engage, or the turbo boost gauge does not register a boost level, it's commonly due to the wastegate not functioning correctly or a blockage in the wastegate hose.

If you notice this problem, it's recommended to contact an experienced diesel mechanic with experience in turbocharged systems immediately to repair the problem before additional damage to the turbocharger occurs.

[Pelican86]

46 minutes ago, GTSBoy said:

Fuel pump.  AFM.  FPR.  Dirty injector.  Blocked fuel filter.  These are the first things to check.  Same as in the 500000000000 other threads that start this way.

Cheers mate, I've spent hours checking hoses etc so far as originally thought intake issue but all seems ok, it's not registering any fault codes either. It idles perfectly, revs clean in neutral etc

[Leroy Peterson]

If rotten egg smell check the intake box for bird nest.

So the issue is only when on boost?
Does it boost or does power die to nothing?
Has the car got any errors up?
Have you ever replaced the AFM?

Much more info is needed if you want us to help

[Ben C34]

Boost leak 

[Pelican86]

3 hours ago, Leroy Peterson said:

If rotten egg smell check the intake box for bird nest.

So the issue is only when on boost?
Does it boost or does power die to nothing?
Has the car got any errors up?
Have you ever replaced the AFM?

Much more info is needed if you want us to help

No it's not showing any errors or fault codes and no I've never replaced the afm. If I feather it I can get a little bit of boost if I nail it it's like hitting fuel cut at red line except it's doinf it at like 3.5-4 rpm. Aside from several  oil changes, tyres and a new radiator I'vebarely spent a cent on it. It's been great! It had 105,000 when I got it and now it's at 160,000 ans yes only on med acc you can feel it's not pulling right and hard it pulls back and kinda pops a bit and jerks then smells. 

I did spill some oil while servicing a few weeks ago and degreased the motor as it was a fair spill but I I've had it running really well for about a week after ans I also replaced the batrery in that period. 

 

 

[admS15]

Ever changed spark plugs?

[Pelican86]

2 hours ago, admS15 said:

Ever changed spark plugs?

Nah I haven't mate. There's so many things it could be making it so much worse and could get real expensive real quick. I'm a fulltime Dad with 2 kids that works 50+ hours per week. My times limited and so is my funding. I need a miracle haha

[admS15]

Well you've done 55k km since you've owned it, you probably dont know when they where last replaced. It would be the first thing id be doing. They would be due anyway. My 2c

[KiwiRS4T]

If nothing else pull some out and have a look. Might persuade you to go mad and buy a set.

[Pelican86]

15 hours ago, admS15 said:

Well you've done 55k km since you've owned it, you probably dont know when they where last replaced. It would be the first thing id be doing. They would be due anyway. My 2c

Thanks mate

[Pelican86]

20 hours ago, KiwiRS4T said:

If nothing else pull some out and have a look. Might persuade you to go mad and buy a set.

Buying a set as we speak, fingers crossed! Thanks guys

[Pelican86]

Thanks everyone, my car is better than ever. The plugs were pretty badly fouled up! However we replaced the fuel filter, and some vacuum lines as well and ran Molli through the fuel tank. Great result, really appreciate the help #backboostin ???

 

And no I didn't film this and it's on the highway ?

20180420_035745.mp4

[Caleb_M35]

On 4/21/2018 at 10:18 AM, Pelican86 said:

Thanks everyone, my car is better than ever. The plugs were pretty badly fouled up! However we replaced the fuel filter, and some vacuum lines as well and ran Molli through the fuel tank. Great result, really appreciate the help #backboostin ???

 

And no I didn't film this and it's on the highway ?

20180420_035745.mp4

Keep an eye on coilpacks also. I experienced all the issues you described earlier on. Replaced plugs, came all good for a week or so and then continued doing it. Found out at least one of the plugs were cooooooked so I replaced them all with OEM replacements and its been good since.