Just got back from the rolling road...

[newsh]

Take it to Newsh's car hospital. He sorted mine out for me, Can u feel the loss of power when u are driving?

I can sort the basics and I know where they tend to leak and a few other little tricks I've learnt since being on this forum.

[1975DCS]

you really need Samcos. Its not only the big hoses either, its all the little vacuum hoses too.

Too bad there is not a complete tailored kit available (according to their website)...
Vacuum hoses: what kind of length and diameter did you order from Samco?

[Robatron]

Take it to Newsh's car hospital. He sorted mine out for me, Can u feel the loss of power when u are driving?

As a matter of fact I can a little, I mean it feels quick, very quick infact, but I assumed I was beggining to get used to the power where in actual fact I believe that feeling is simply a loss of power.

I would say mostly hose failures through age, I'm running upwards of 360bhp on stock clamps but the old rubber hoses wouldn't take it, new ones might work for a while but you really need Samcos. Its not only the big hoses either, its all the little vacuum hoses too.

You know the car very well as it was infact Dan_b's motor so I am very safe in the knowledge that it has been looked after and also has samco boost hoses fitted.

I really do appreciate all the help and I would love to get to the bottom of this.

[Robatron]

So I left my rolling road graph at home today!

I shall bring it in tomorrow and scan it so as you guys can take a peak at it.

[dan_b]

Rob - has the Wastegate diaphragm been replaced?
Newsh - you know the car well, you helped install all the Samcos and the PCV hoses in there

[Robatron]

No it hasnt Dan. Does this sound like a possible cause?

[LHD_Kid]

Too bad there is not a complete tailored kit available (according to their website)...
Vacuum hoses: what kind of length and diameter did you order from Samco?

There is almost a tailored kit available from S2central.net AKA Paul, but in addition you will need the 4mm vacuum hose (3B, for all engine bay and to the ECU and boost gauge 4 metres, ABY I think is a little less, but its cheap anyway) and a length of 8mm straight (1 metre)
Plus a myriad of clips
Expensive but worthwhile...

[dan_b]

Was just speculating to myself - just wondered if a leaking wastegate diaphragm could give the issues you've got? I never changed it when I owned the car. Probably best to eliminate other possibly more obvious causes of boost leaks first though?

Still concerned about your aircon power sapping problem too. Wonder if that could be related?

[Robatron]

I agree with you, I think it could be related to the aircon.

I got a bit of a chance on the way to work to push it a little today and there is definatly bags full of torque there, just not all the power it should have...

[newsh]

There's a hose missing from the samco kit which is the one from the ISV down to the IM, 20mm bore small elbow shaped. could be that one.

Remember when we fitted the MarkH mod we had to jack the IC up to the crossmember, I bet a garage wouldnt do that. I think I'd whip the bumper off and have a look.

Leaky wastegate diaphragm would mean too much boost, overboost cutout..

[terrybullwon]

There's a hose missing from the samco kit which is the one from the ISV down to the IM, 20mm bore small elbow shaped. could be that one.

Remember when we fitted the MarkH mod we had to jack the IC up to the crossmember, I bet a garage wouldnt do that. I think I'd whip the bumper off and have a look.

Leaky wastegate diaphragm would mean too much boost, overboost cutout..

Um...... i never got that hose either

[Robatron]

John, the mechanic did indeed take the IC off so that is very plasuable!

I dont know how to take the bumper off or jack the IC up though...

[Robatron]

Oh I just remembered something else, when the car is at idle it starts hunting ever so slightly, not rapidly just the needle will slowly go up and down about 50/100rpm and obviously in doing so the oil pressure either drops or gets higher.

Could this be caused by the leak or something more sinister?

[s2dude]

Could possibly be the ISV (idle stabilisation valve)..
Have a search for how to clean it. That cured my cars hunting idle totally.

[Robatron]

I have plenty of carb fuel so cleaning it shouldnt be a problem. Thanks.

I have a question for you though, when the car was hunting, did you have a slightly irratic oil pressure? Not moving a great deal, maybe only 0.1/0.2 of a bar, but did it move somtimes very quickly and make the car feel ever so slightly lumpy?