Author Topic: Random Power Loss  (Read 2259 times)

Offline AdzCM

  • Members
  • *****
  • Posts: 472
Random Power Loss
« on: July 22, 2013, 06:54:46 pm »
Have my polo turbo'd and mapped. Got it all set up probably over 2 months ago. Everything was going well.

Recently i've found myself constantly putting more and more preload onto the actuator to maintain 18psi. Is this normal or do I have a boost leak? Its the red spring. Is it normal for them to wear down with the extreme heat etc?

Now for the strange thing. Went for a spirited burst up the road. Pulled well then all of a sudden, when I went to burst it again, it pulls well to about 4/5k rpm but only reaches maybe 10psi of boost, and it just bogs down/doesn't go anywhere and there's an awful rumbling noise. The noise is a fast, intermittent 'burrrrrr' haha, if that makes sense.

Anyone any ideas on what to check for?

The car drives 100% off boost. And when it 'rumbles' under hard acceleration, its not really smokey.

Adrian

Offline Etches

  • Members
  • *****
  • Posts: 1378
  • Still got the G...
Re: Random Power Loss
« Reply #1 on: July 22, 2013, 06:57:22 pm »
Sounds like a turbo issue to me dude, you using a second hand one?

Offline GR40

  • Members
  • *****
  • Posts: 431
Re: Random Power Loss
« Reply #2 on: July 22, 2013, 11:24:36 pm »
Check inside your hoses too! I had a similar problem with that short of noise and it turned out to be a metallic ring that had slipped off my plastic pipe end, moving around inside the pipes and blocking the sensor! I know it's a long shot to be the same problem as mine but you never know!

Offline AdzCM

  • Members
  • *****
  • Posts: 472
Re: Random Power Loss
« Reply #3 on: July 23, 2013, 01:47:56 am »
Sounds like a turbo issue to me dude, you using a second hand one?

Yeah mate, its strange though. Sometimes I can get it to pull the whole way to the red line in 2nd I've noticed. Really plays up in 3rd and  4th at the same boost/rpm. I'm lost like. I don't want to have to take it off the road yet :( too much fun...it could be the turbo tho...cheers.

Ill check the pipes, its worth a try. Though I doubt it unfortunately.
Cheers.

Offline AdzCM

  • Members
  • *****
  • Posts: 472
Re: Random Power Loss
« Reply #4 on: August 15, 2013, 07:00:57 pm »
Right, this is really bugging me..

I don't know what to look for.

the car drives fine off boost. If I put the foot down and change at 4krpm, all is fine. Anything above that, the car bogs down and I just hear the rumbling noise at round 10 psi. Boost slowly then reaches 15+ psi.

One time I wiggled the wiring loom, took the car out and it went 100% for 300m. Turned to come home and it was back to the rumbling noise again :(

Faulty ECU?
Faulty Wiring loom?

I've disconnected the blue temp sensor. Revs dip and it barely drives so it cant be that.

Disconnected the lambda sensor and it made no difference at all? Should it drive better it the lambda was at fault?

Could  a wire to the boost switch be at fault? Or would that mean it would run crap at idle since the boost switch is wired to the idle switch?

The spark plugs are white indicating it isn't getting fuel at all on boost? Running seriously lean. Can throw up a pic if need be.

GIVE ME SOME SUGGESTIONS PLEASE :(

Offline Yoof

  • Traders
  • *****
  • Posts: 2355
  • I know naathing..
    • Polo Performance Parts
Re: Random Power Loss
« Reply #5 on: August 15, 2013, 10:01:25 pm »
Who mapped it? Did it run well once mapped?

Fuel system healthy?

Sounds like you have a boost leak or a tired turbo is there any play in the turbo shaft, oil in the boost pipes? Dump valve okay?

Sounds like you knw you have a wiring issue too, was the boost switch setup pre-mapping?

Offline AdzCM

  • Members
  • *****
  • Posts: 472
Re: Random Power Loss
« Reply #6 on: August 16, 2013, 03:22:57 pm »
Who mapped it? Did it run well once mapped?

Fuel system healthy?

Sounds like you have a boost leak or a tired turbo is there any play in the turbo shaft, oil in the boost pipes? Dump valve okay?

Sounds like you knw you have a wiring issue too, was the boost switch setup pre-mapping?

A company over here in n. Ireland. He did an amazing job. Car was running 100% this past 2 maybe 3 months since it got mapped.

I don't think there's a boost leak but that would explain why I constantly had to addmore preload every once in a while to maintain 17/18 psi.....would a worn turbo mean the need for additional preload?

There is some oil in the boost pipes, but nothing alarming. Shaft play is minimal. The car goes 100% the very odd time. Does a turbo not just 'go' n that's the end of it?

New upratedfuel pump n the injectors seemed fine this past while. Never had them cleaned though...

Has to be a lack of fuel rather than boost? The plugs are white and there is no smoke if I accelerate hard :s

I've checked the wiring and connections visually n all seems well. If a wired disconnected from the boost switch, would the car run crap at idle since the idle switch is wired in line from the boost switch (originally full throttle switch) ?

Thanks for the reply buddy