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Going the the boxes of bits I have, I pulled out the three Delco solenoids (EGR, throttle jack, boost) specifically because I wanted to know which was which. I noticed that my boost solenoid has a connection to the wastegate and the turbo compressor. But it also has another tube which has been blocked off.

Now when I looked at the parts manual, it seems that connection should have a filter at the end. As I understand it, the solenoid bleeds off air from the wastegate, but how can it do that if the connection is blocked? The car did show 1 bar on the boost gauge at full throttle, prior to me ripping everything to pieces, so I'm a bit curious.

Margate Exotics.

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Hmmmm. So why is mine blocked off?

 

OK, here's a scenario: The boost solenoid fails, so the PO blocks the relief port, and resets the turbo wastegate to give 1 bar mechanical boost. Call me old Mr. Suspicious, but I cannot see any way the solenoid was operating with the port blocked.

 

Is there any way of testing the solenoid out of the car, as it's all in bits right now.

Margate Exotics.

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Testing is easy: rig the intake to a (low) pressure supply, connect 12V to the solenoid and check for escaping air. There should be none without the 12v supply.

I have made many mistakes in my life. Buying a multiple Lotus is not one of them.

 

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  • 4 weeks later...

My boost gauge has gone all 'floppy' it sets at rest far over to the left of gauge, but when boosting i am only seeing .5 bar (but i know by the feel etc that it is fully boosting so no problem there) anyone have any ideas,maybe the gauge has just died?

 

 

Hmmm come to think of it when the car over boosts which does happen occasionally the needle flicks like a mad thing.....so i'm thinking busted gauge.

Simplest things first.

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The gauge in the dash gets its signal from the boost transducer tucked up under the bodywork by the right side fuel filler.

 

There is a rubber hose from the plenum (white line here) 

post-15426-0-65677400-1369939298.jpg

 

So it could be that the rubber hose that connects the hose to the transducer is cracked.

Rubber elbow shown here is to the MAP sensor BTW, the boost transducer is attached to this same plate.

 

DSC02545.JPG

 

It could also be the electrical connector to the dash gauge.

Travis

Vulcan Grey 89SE

My Lotus Photo and Projects Album

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No, it is bolted up in the buttress behind the right quarter window, next to the solenoid to open the fuel door. There are two bolt heads that you can see through the body when the hatch opens.

Travis

Vulcan Grey 89SE

My Lotus Photo and Projects Album

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Found it,it is behind the r/h quarter light panel sits almost on the tank,vac pipe was in good condition ,electrical connections and wire really shabby (looks like heat damage),but gauge does flicked when pulling connector off ,so i,m erring towards a bad transducer.may take it off whilst repairing wiring and give it a technical clout ,if i bridge the two connection's will the gauge just go to full deflection does any one know??

Simplest things first.

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Update,fitted second hand 'new' gauge works a treat,also heli coiled errant engine mounting bolt,what a diffence a tight engine makes! I really should hang my head in shame for not addressing earlier.

Eta.Spelling and various words missing.

Simplest things first.

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  • 3 weeks later...

Back on course, I've just checked the boost solenoid. I removed the blocked-off rubber pipe from the bleed connection, put the pipe that comes from the compressor to solenoid in my mouth, blew through it, and air escapes through the bleed port that should have the sponge on it. There was not a lot of resistance at all. That is without any electrical connection.

 

I don't think it should do that, should it?

Margate Exotics.

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Update: just tried 12v across it, and the solenoid clicks.

When I try blowing through the input tube with power on it, I can't, it's like it's been shut off. I haven't tried any compressed air at 14psi, though. But it seems 'not right' that I can blow through it at all.

I measured the resistance at 23 ohms.

Margate Exotics.

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Thanks Derek.

 

So given that information, the dump port on mine was definitely, and deliberately, blocked off. And if I'm right, then the effect of that would be that the solenoid would be unable to control boost over the wastegate mechanical setting. I did witness 1 bar on the dashboard boost pressure gauge, so I can only imagine that some previous individual had jacked up the wastegate rod until that pressure was reached.

 

But why would they do that? It sounds a bit dubious to me.

Margate Exotics.

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Perhaps Stimpy is one of the PO's? :hrhr:

88 Esprit NA, 89 Esprit Turbo SE, Evora, Evora S, Evora IPS, Evora S IPS, Evora S IPS SR, Evora 400, Elise S1, Elise S1 111s, Evora GT410 Sport

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