Masssive overboost

[CoochiGT]

Right, I swapped Turbo's at the weekend as mine was smoking on idle. I swapped it with a second hand one from a mate who'd just swapped his across to a CT9b. It was fine on his car, no problem's, although it did have a cracked wastegate but it got me out the s**t.

Ever since fitting it, I drove it today, went to hit boost and it hit 29.8PSI . Fuel cut kicked in to and I let off as soon as it did it. Had a chat with Ricky (sx_turbo) and my Bro and discovered I'd put the vacuum pipe's on the wrong way round. I'd put the one from my Boost Control Valve that said COM to the actuator and the NO side to the compressor. Swapped these over and drove it down the round, exactually the same but not over boosting as much. What would be the likely cause? I've checked the boost hose's for split and could see and visable splits. The vacuum hose's look ok too, I'm now at a loose end.

Thanks

 

[Jay]

The 'bastard' hose at the rear of the turbo (the one hardest to get to) will allow the rather cool-sounding albeit deadly infinite boost if it is leaking or becomes disconnected.

Check that mate.

 

[monka]

bypass the solenoid see what that does.


you may also want to check your headgasket, i had this once, and my headgasket has gone

 

[CoochiGT]

The 'bastard' hose at the rear of the turbo (the one hardest to get to) will allow the rather cool-sounding albeit deadly infinite boost if it is leaking or becomes disconnected.

Check that mate.

Not sure what one you mean Jay, On the actuator?? Or on the compressor? I swapped them over about 10minutes ago and checked at the same time.
And Monka, D'ya mean bypass the boost control valve? What will this achieve?

Thanks
Dan

 

[Jay]

You know the hard tube that starts at the PAS pump and leads down to behind the turbo - if that baby comes loose you get infinite boost. In the words of Egon Spangler - Not good.

 

[CoochiGT]

Hmmmmm, not sure what pipe your on about Jay, that might the problem then......... How big is it? And does it go above the EFI Pipe on a kinda of hex shaped thing with one pipe outlet?

 

[Jay]

Hang on a second matey. Sorting a pic or three now.

 

[CoochiGT]

Thanks, sorry for being a pain

 

[Jay]

Top left corner - part ID 17303B is the hard pipe that leads from your cambelt cover down behind the manifold. If the tube that connects to the turbo (part number 90445-12158) comes loose then it's bad news for your turbo.

 

[CoochiGT]

I still can't picture it Jay , I'm getting really worried now, cos not being able to picture the pipe I am thinking I haven't connected it. The strange thing it, I only remember connecting the 2 vacuum hoses which both go to the boost control valve for the profec EO-1.

What would it do to the Turbo then if it was loose, or not connected?

 

[Jay]

Head to your engine bay and have a good rifle through the connections mate. It's not uncommon for the hard pipe to be removed and replaced by aftermarket piping so don't fret too much.

Usually the CT9 dies a horrible death but some have been able to get away with it. Just make sure you get the engine checked over - fuelcut will have saved the day hopefully.

 

[CoochiGT]

Ok Jay, Thanks, and yeah it wants to of lol.

What part of the Turbo does the "hard pipe" connect to please? As I only remember connecting the EFI Pipe, the hard pipe for the IC/Boost hose's and two vacuum hose's.

 

[Spoonz]

maybe this may explain it a bit easier. 1st of all you do have a standard Actuator dont you?

If so then the actuator has to outlet 1 for high 1 for low.
now the high out put is the one you can see.
The low out put is on the other side of the actuator if you grab the actuator and move your hands round to the back of it you should be able to feel it

 

[weakboy2]

no, the solenoid governs high and low, the two outlets on the actuator just act as a T-piece.

Just block one of the actuator outlets and connect the other one directly to the outlet nipple on the turbo. Block all the other loose pipes and see what boost you get then, should be about 0.5 bar

 

[Spoonz]

yea but you know what i mean lol

 

[CoochiGT]

Does it matter which actuator outlet is blocked?

And I will do that tonight and let you know, surely if i'm not connecting it to my profec eo-1 it'll boost as it please's? And my profec won't tell me what pressure i'm running either, due to be disconnected? Could it be a dodgy actuator?

 

[sx_turbo]

i bet you got some boost pipes the wrong way round or something.

is your brother not able to spare 5 mins and have a quick look for you?

specially seeing as he knows these cars inside out.

 

[CoochiGT]

After talking to you Mr Rick I swapped the suspected pipe's over and still the same. And no he's going out and we not on best of terms atm.

 

[sx_turbo]

bloody family's

i cant do anything till the weekend.

if it's still playing up at the weekend, i dont mind popping over and having a look

 

[CoochiGT]

Cheers hun. I did have the boost pipe's ok first time round, gonna go and swap them and check the other's are blocking off properly. If not i'm just going back to stanard for time being. Thanks Rick, I'll let you know.