Higher idle RPm & temp gauge

[Quack]

Few days later of testing, still having issues. It’s fine in the morning however after one drive, and during the drive, the revs are higher on the tacho. Seems to get higher throughout the day even.

mat first I was convinced it was a misreading but now I am certain it’s not. I can hear the difference, the car at idle sounds like if the pedal was slightly pressed, running a bit faster.

I’m thinking either the throttle or choke is sticking but I’ve tried pulling both back and still nothing. Really strange.

[Quack]

Oh also I checked my alternator, putting out expected power so no issues there

[Iain T]

Can you post a picture of your carb/throttle arrangement. 

If there was a butterfly screw missing it would have high idle all the time, see Jeffds1360 post. 

It sounds as though something is moving after running the car then possibly settling down and returning when not in use. Odd, wierd but it must be something simple. 

Iain 

[Pete Lewis]

this is a 13/60 so runs a single stromberg 

have you checked the diaphragm for small holes and make sure the  2  location lugs are both located 

if you look down the air piston the two holes in its base must face the engine side or its wrong 

Pete

 

[AlanT]

Is power still down when driving? If so then I’d be checking compressions to be sure there isn’t anything fundamental at play. Then onto either fuel or electrics. 

[Quack]

[Quack]

Turned it on and warmed it up, sitting again at 1500ish idle, but nothing looks different around the carb area. Still sounds as if throttle is being slightly pushed even though it’s clearly not

[Quack]

Ok more news, not sure if this means anything. I have the engine running and I spray starting fluid in to the carb, the idle momentarily slows down to a more normal speed. Or is this normal?

Is there maybe a vaccum leak? Too much air getting in? I thought if anything it would rev up!

[NonMember]

If you spray starting fluid into the intake of a correctly tuned engine, then the mixture goes horribly rich and the engine stumbles, so the revs drop. That's normal. If it revved up then that would be an indication of too weak a mixture, possibly caused by an air leak.

[Pete Lewis]

much of this running and stumbling can arise from diaphragm problems have you checked that out ???

Pete

[Quack]

You’ll have to excuse my lack of knowledge but I’m not actually too sure what that is or what I’d be looking at Pete, doing some googling now

[Quack]

42 minutes ago, Pete Lewis said:

much of this running and stumbling can arise from diaphragm problems have you checked that out ???

Pete

All seems well 

[Quack]

[Paul H]

1 minute ago, Quack said:

All seems well 

Not sure if it’s the pic but the upper left side seems like it’s cracked on the rim 

Paul

[Quack]

The dread continues, just pulled out my spark plugs to find they’re all coated in oil…definitely contributing to some of the misfiring

[Iain T]

As Pete said what about the air piston are the holes at the bottom pointing toward the engine? 

[Quack]

Where/how do I see this?

[Iain T]

After checking the air piston orientation screw the top back on then with the air filter off (and the damper plunger out) stick your finger in the carb and raise the air piston to the top then let it drop. Does it drop all the way with a mechanical clunk at the bottom. If it doesn't the jet needs centering to the needle. 

Note: when screwing the carb top on take great care to evenly turn each screw and check alignment by raising the air piston and letting it drop with a clunk. 

Iain 

[Iain T]

8 minutes ago, Quack said:

Where/how do I see this?

From your photo just pull the diaphragm/air piston assembly up from the carb body. At the bottom of the piston are two holes which must face toward the engine/manifold 

PS

I've PM you with my mobile number. 

[AlanT]

Worth compression testing. You can then relax knowing it will be relatively minor…

[Quack]

Yep they’re facing it

[Iain T]

6 minutes ago, Quack said:

Yep they’re facing it

One down, now try the piston lift check. 

[Quack]

Wouldn’t say a mechanical clunk, more just a thud from landing 

[Iain T]

Possibly not down. When the piston is down is there a gap at the bottom between it and the bridge of the carb body? 

[Iain T]

If there is a gap then the jet needs centering.