Renault Turbo Trouble - plse help!

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Sun 24 Nov 2002 12:02
Renault Turbo Trouble - plse help! - julian HH
I have a Renault 21 Turbo, phase 1 modle reg is 1988. I paid not much for it and have had a new head gasket fitted. It has a BBR conversion on a button to 240bhp. std 175. This was done in 1993. It goes sweetly and the turbo is strong - save for when I really put my foot down in 3rd, 4th or 5th. The boost comes on strongly as usual, but then, it kinda "cuts out" intermitantly, almost slowing the car. Its like I have switched off the ignition and switched it back on again. If you like, a bad misfire but worse. Some may call it "choking". It is sevre. I have to take my foot off the gas a bit to allow it to clear. Gentle application of throttle is ok. It happens on std boost or otherwise. High boost makes it worse. Part throttle with full boost is fine and pre boost there is not a problem. When the head was done, the hoses were checked and they are ok. I have new plugs, rota arm and cap and the leads seem to be newish and do not outwardly show signs of trouble. I may replace these and see but I feel that I am not getting to the root of the problem. There is no oil leak nto the distrib either which these cars can do. So I am confused. Can you help? It is a 1995cc engine [f inj] with a garrett t3 turbo. Is it fuel or electrics. Any help greatly appreciated!!

Julian
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Sun 24 Nov 2002 12:41
Renault Turbo Trouble - plse help! - madf
could be a faulty wastegate actuator or valve that controls it. As revs rise it should close the wastegate allowing pressure to build up. What you describe sounds like a failure to achieve any boost pressure at high throttle openings.

As you say part throttle boost is OK, it sounds as if the actuator itself is sticking which could be a valve problem (not signalling actuator) or the actuator itself (gummed up or just worn out). Check all the wiring connections from ECU to valve (sorry I'm not familiar with the car) first. Then if they are Ok, you really need specialist help .. from an auto electrician used to turbos.. preferably with access to a rolling road.

(As revs rise the ECU sends increased signal pulses to the valve. )





madf
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Sun 24 Nov 2002 20:24
Renault Turbo Trouble - plse help! - julian HH
Cheers, I will have a look. It is odd as I do get good boost on part or half throttle. How do you go about cleaning the actuator - is this just a job for a specialist? I.e turbo off etc?

Thanks

J
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Sat 7 Dec 2002 13:16
Renault Turbo Trouble - plse help! - dan
Could you bypass the ECU solenoid for controlling the wastegate to a manual bleed. ECU can do funny things if it thinks its stopping you blowing yourself up.
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