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Question: Vacuum leaks

Antz81

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dougelam

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It should work

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Antz81

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This is the rebuild kit I have. 20160426_182846.jpg
And these are the specific carb tools20160426_174325_001.jpg
Plus i have the choke angle gauge on it's way. It and the other bits and pieces should arrive early - mid May.

As for vacuum leaks, I think I only have one very small one left somewhere in the cabin vent controls. (Although it doesn't seem to make any difference if I block this off or not.)
 

dougelam

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2002 Roadster
Even a new MC solenoid, nice
How about a hand held vacuum pump?
The carb feet are nice to use but 4 bolts will work OK, that and a little patience

Keep us informed

Doug

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Antz81

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Yes do have a hand held vacuum pump. It's a must when working on these cars.
Don't carb feet, I was going to make something at work, but four bolts sounds a lot easier.
 

Antz81

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OK. Did a few more checks today. Idle is nice and smooth, with and without everything disconnected. When spraying WD-40 around the idle stays the same, so I pretty sure I have found all of the vacuum leaks. (Except for the one in the air-con controls. I'll get to this when I replace the dash)
 

dougelam

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How does it run when cruising?
Good throttle response?
Decent power?

Are you headed into winter down there?

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Antz81

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Cruising is fine also.

Yes winter is approaching. Things don't get too cold here though. 0*C overnight 12-15*C during the day. Not sur what that is in *F
 

Antz81

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One thing I do remember now that I think about it. The run on issue only started after raising the idle speed. It's currently at about 750rpm, but if I try adjust it any lower it drops down to about 500. Ideas?
 

dougelam

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I believe heat is needed to ignite the fuel, sounds like there might be some carbon build up in your combustion chamber

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Antz81

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I believe heat is needed to ignite the fuel, sounds like there might be some carbon build up in your combustion chamber

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Quite possible I guess. It was running very rich when I got it. I might see if I know anyone when a small inspection camera and see if I can see anything in the cylinders.
 

dougelam

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Or your spark plugs are hot like a glow plug
A quick H2O carbon blast would help narrow down the cause

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Antz81

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I believe heat is needed to ignite the fuel, sounds like there might be some carbon build up in your combustion chamber

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looks like you might be right. Not the greatest pics, but does seem to be some carbon.

Snap0001.jpg cylinder #4
Snap0002.jpgcylinder #4
Snap0003.jpgcylinder #2 I believe the white spots are the bare metal on the piston.
Snap0004.jpg cylinder #2 I believe this is the piston. Note the scrape marks that appeared after I tried scraping a little with a small hook.
20160502_164954.jpgSpark plug appears ok to me. But again note the carbon around the outside ring. All the plugs I pulled were the same.

So what do you think is my best option from here?
 

dougelam

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Looks like a hot plug running rich

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dougelam

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How much driving time do you have left this season?

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Antz81

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I'm guessing i'll need a new set of plugs again then. (These ones have lasted better though, the one that were in it when i got it fouled up because of how rich it was, and in less time)
The plug currently in there are NKG BPR4FS (Can't find delco plugs here, but this is meant to be the equivalent of the R45TS) What would you recommend?

As far as driving time goes, it never gets cold enough here to require the car being put away for the winter. I just won't take it out on the rainy days. But I do try to plan the bigger jobs for the winter.
 

dougelam

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Since you have a distributor I personally would go with the R45TS plugs ($22.50 from Amazon) because they will last past the 75K miles and that is when you should be replacing plugs, wires, cap & rotor anyways.

At this same time I would go then through the carb.

When you were checking for vacuum leaks did you check the intake to cylinder heads?

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Antz81

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Haha ordered a set of 8 r45ts plugs from ebay (the only set i could find on amazon wouldn't ship to nz) even with the shipping being almost the same as the plugs I'm still paying less than i would for a set locally.

Yes i did check around the intake manifold to the heads.
 

Antz81

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The PCV and coolant sensor arrived today. Both now fitted, but was unable to take it for a test drive. I did notice the new PCV had a tighter fit than the old one, not sure if that will effect anything. (If it does it'll only make thing better)

I showed the engineer at work all of my spark plugs. He did notice something interesting. Cylinders 2, 3, 5,and 8 seem to be running a bit lean compared to the others. This lead to an interesting observation of the intake manifold layout, it seems cylinders 2, 3, 5, and 8 run off the same side of the carb; I'm not sure I think that's the passenger side. Anyone know for sure? It seems like I may need to increase the fuel on that side a little bit. If no-one is sure I'll remove the carb this weekend and have a look.
 

dougelam

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I believe you are correct, another reason to clean and recalibrate your carb

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