Power problem, maybe, help!

This has happened a few times now and I only really get to test it on motorway drives which I don't do many of at the moment. But I noticed a intermittent problem.

When I am cruising along at 80 or 70 for a while and then I put my foot (almost) flat down the car revs up and changes gear if needs be but it doesn't seem to have the power there. It does accelerate but it's a little juddery up until 90 then it's normal after that to go up the speed. But if I go from a much lower speed like 30 it goes past 70-80-90 without a problem.

It literally only happens if I have been cruising for a little while sticking at that one speed and sometimes it just doesn't do it at all.

I noticed it being a problem when some bloke was sitting so far up my arse I could smell his farts and I put my foot down to get away but he didn't exactly disappear like I expected :/

I should point out my car is a completely stock TT VVTI and you will see in my signature.

So at 30mph if you floor it, are you saying that I does not have the same hesitation, or is it only noticeable when you are at WOT (wide open throttle)?

Doesn't have any hesitation if I plant my foot anywhere between 0-60

It accelerates past 70+ as normal

Sounds like a VSV error in my opinion, I had a similar issue on my stock twins, admittedly on a manual box, but if I dropped it down into higher revs it would not boost, I had to slow down, then go for it and it would boost fine, was also fine if I just accelerated through the gears, only ever an issue if I dropped down into a gear that put the Revs at 4k+ rpm.

Sounds like a VSV error in my opinion, I had a similar issue on my stock twins, admittedly on a manual box, but if I dropped it down into higher revs it would not boost, I had to slow down, then go for it and it would boost fine, was also fine if I just accelerated through the gears, only ever an issue if I dropped down into a gear that put the Revs at 4k+ rpm.

That's exactly what I'm having. What's VSV? And how do I fix/check it?

That's exactly what I'm having. What's VSV? And how do I fix/check it?

They are small vacuum sensors that do occasionally fail over time, Your best bet is asking someone like Kieran at Extreme Performance on here if he has any lying about, nice and easy thing to replace

They are small vacuum sensors that do occasionally fail over time, Your best bet is asking someone like Kieran at Extreme Performance on here if he has any lying about, nice and easy thing to replace

Thank you I'll get on that.

I'm not sure if the VSV's from VVTi cars differ from non VVTi variants, but might be worth checking before purchase.

It's difficult to tell from your description whether it's an auto gearbox drive issue or a problem with the turbos/power.

Do you have a boost gauge fitted? Is it behaving normally ie. boost rising to normal levels as you accelerate? Usual surge as the 2nd turbo spools up, etc.

If boost pressures are normal, then it sounds like an auto gearbox issue.

If the boost pressures aren't normal then it could be a vacuum line popped off, IC pipe leak, sequential turbo valve not working properly, etc.

It's difficult to tell from your description whether it's an auto gearbox drive issue or a problem with the turbos/power.

 

Do you have a boost gauge fitted? Is it behaving normally ie. boost rising to normal levels as you accelerate? Usual surge as the 2nd turbo spools up, etc.

 

If boost pressures are normal, then it sounds like an auto gearbox issue.

 

If the boost pressures aren't normal then it could be a vacuum line popped off, IC pipe leak, sequential turbo valve not working properly, etc.

I do have a boost gauge fitted. I remember it working fine and the boost reading as it should but I will test it again to be sure.

If it is a problem with the auto box would I not get problems at other times?

I was thinking that it was the turbos taking their time to spool up. But I'm guessing that wrong.

I will check everything you've listed and I will check out that link posted in the next comment as well.

I do have a boost gauge fitted. I remember it working fine and the boost reading as it should but I will test it again to be sure.

 

If it is a problem with the auto box would I not get problems at other times?

 

I was thinking that it was the turbos taking their time to spool up. But I'm guessing that wrong.

 

I will check everything you've listed and I will check out that link posted in the next comment as well.

To me personally it does sound like a turbo related problem, VSV, vac hoses, or a sticky actuator, but more likely previous two, also don't think it would be an IC hose, as that would send you almost into a limp mode, well it did to me anyway when the hose popped off. Mine was the hose that goes from the intercooler to the throttle body

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I do have a boost gauge fitted. I remember it working fine and the boost reading as it should but I will test it again to be sure.

 

If it is a problem with the auto box would I not get problems at other times?

 

I was thinking that it was the turbos taking their time to spool up. But I'm guessing that wrong.

 

I will check everything you've listed and I will check out that link posted in the next comment as well.

To me personally it does sound like a turbo related problem, VSV, vac hoses, or a sticky actuator, but more likely previous two, also don't think it would be an IC hose, as that would send you almost into a limp mode, well it did to me anyway when the hose popped off. Mine was the hose that goes from the intercooler to the throttle body

I have a feeling I am having the same issue and it could be VSV related where the engine has been sat for so long.

The boost readings should give you an idea whether it's a turbo or drive issue.

Do a test drive and check what the boost gauge is doing at the specific time you are having the problem.

If it is turbo related these threads in the FAQ section should help. I'd start by checking all the vacuum pipes to see if one has popped off or split.

http://www.mkivsupra.net/vbb/showthread.php?35926-The-sequential-system&highlight=sequential

http://www.mkivsupra.net/vbb/showthread.php?35924-Sequential-turbo-hoses&highlight=sequential

http://www.mkivsupra.net/vbb/showthread.php?27904-Sequential-turbo-problems&highlight=sequential