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TR2/3/3A Idling issues and gauge readings.....

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K

karls59tr

Yoda
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When the engine is at operating temperature it wants to idle at 12 to 13 grand and sometimes up to 15. Seems to me others on here get their cars to idle a 800 rpm? I do have a mild street cam so that might account for some of the difference in idle speed. I tested the throttle shafts with a drop of oil to see if they were worn but it did not seem to change anything? If I kick down the pedal at idle at a stop light the rpm will often drop down to 10 grand and below and it feels like it is about to stall out? The car runs fine otherwise. Any thoughts?
 
10 grand ? that's 10,000 you know ?
Sounds like there is an air leak down stream of the carbs.
 
Karl - one way to find an air (vacuum) leak ... use aerosol carb cleaner.

Let engine idle. Lightly spray carb cleaner where there might be a leak: carbs, gasket areas, hoses, intake manifold, anything downstream of the carbs.

If the idling engine speed changes when you spray a given point, you've found the area of the air leak.

Tom M.
 
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Back your idle adjustment screws all the way out so they don't contact the stops and see what happens. It should stall or go to a poor, low, idle. If high idle persists, you may have a mechanical bind in the shafts or linkage. To check for air leaks, pull and push on the manifold. Idle shouldn't change. You have not reported that you had the manifold off since the head work, so I doubt this is a problem.
Bob
 
bobhustead said:
Back your idle adjustment screws all the way out so they don't contact the stops and see what happens. It should stall or go to a poor, low, idle. If high idle persists, you may have a mechanical bind in the shafts or linkage. To check for air leaks, pull and push on the manifold. Idle shouldn't change. You have not reported that you had the manifold off since the head work, so I doubt this is a problem.
Bob
Click to expand...
I have had the manifolds off a couple of times since the head work as I had to remove them to access the starter because I was sent the wrong starter and had to install a different one .Another thing that's happening is that there is a stumble or hesitation on acceleration....... It sort of feels like when you mistakenly leave the handbrake on and it just feels like something is holding the car back but not that severe? Would an air leak at the intake manifold create that effect? I did get a raise in rpm when I squirted carb cleaner on the intake manifold near the back of the motor close to the firewall. Is this just a matter of re torquing the intake manifold in that area or maybe adding another washer there? I am running an exhaust header rather than the stock exhaust manifold. Maybe that is somehow causing the intake manifold to not seat properly???? I will pull and push the manifold like you say and see what happens. Any thoughts on how to proceed?
 
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When it idles that high it throws off your idle circuit. If you set everything up right, it should idle all day at 700, although it's common to have a sticky throttle linkage that will occasionally bump the idle up to 900-1000rpm. Pull the gas pedal up with your toe if that happens.
 
Yes Karl
The rise in revs mean it’s sucking in the carb cleaner.
You can try loosening the rear carb / exhaust to head mounts give them a shake push to make sure they don’t hang up on each other and re tighten the clamps.

You did renew the exhaust/inlet gaskets when you moved thinks to fix the starter ?!
As once fitted and crunched they don’t un- crush to be reliably used again.

Edit
Ive commented on you other manifold post.
 
While the revv rise with the carb cleaner is a problem, you may have more than one. When checking linkage, make sure you did not bend the linkage shaft that runs across the firewall behind the engine.
Bob
 
Hamish Racing said:
Yes Karl
The rise in revs mean it’s sucking in the carb cleaner.
You can try loosening the rear carb / exhaust to head mounts give them a shake push to make sure they don’t hang up on each other and re tighten the clamps.

You did renew the exhaust/inlet gaskets when you moved thinks to fix the starter ?!
As once fitted and crunched they don’t un- crush to be reliably used again.

Edit
Ive commented on you other manifold post.
Click to expand...
When I changed out the gaskets after removing the manifolds I did notice that the old gaskets showed a black carbon trail going outwards towards the rear at the back gasket and similar at the front gasket which leads me to believe that the header flanges really are narrower than the intake manifold flanges so that when the manifold bolts are tightened they create a gap at the intake. So AI says you have to create a level surface there by using washers to make a level surface. Ideally you're supposed to use a caliper to see what the difference is between the header flange and intake manifold flanges and make a suitable shim to create a level surface. Hopefully I will only have to do this at the back where I detected the leak but I will retest all the mating surfaces with the carb cleaner to make sure. I really don't want to pull the manifolds for a 3rd time but I hear what you are saying about the crushed gaskets. Interestingly AI mentions that on the TR3 not only can the clamping bridges be misaligned but " but the intake gasket may have slipped off the locating dowels on installation." Also manifold binding bolts must be left loose until perfectly mated to the head then tighten in stages from the inner bolts to the outer in 3 progressive stages 15ft lbs 25ft lbs 30 to 35 ft lbs.
 
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