Butch:
I have gone through this exact scenario over the last winter.
My case is extreme, but covers a lot of bases. My car is not yet
completely reassembled, but I can share my findings, in the hopes that
they will give you some areas to examine.
My car would not idle without at least some choke, and would
idle only roughly. It was difficult to start for a variety of reasons.
Most of my issues could be summed up as terrible maintenance by the
DPO. In your case, it may simply be age.
I am making the following assumptions, so if these are wrong,
please correct me:
1. The valve job was done at the same time as the carb rebuild.
2. The car has only had this problem since the carb rebuild and
valve job.
3. You have set the timing per Bentley, and at least tried to
set
the carb mixture per Bentley.
4. You are running stock ignition, and your vacuum retard is
installed per the original factory installation.
5. You have not disconnected any pollution controls, such as
EGR, anti-run on valve, carbon canister, etc.
6. You have a stock, or nearly stock camshaft.
7. You have properly set the valve lash, per Bentley.
8. That you used the correct late model intake manifold gasket
when you reinstalled the head. (My DPO used the earlier
style gasket, which blocked the intake ports. Idiot.)
9. You used the correct, late model head gasket and that
you installed it right side up.
10. You installed a fresh set of correctly gapped plugs
after the valve job.
OK, things to check:
1. Vacuum leaks. Use a propane torch (unlit, of course) and
spray propane around the intake manifold, vacuum hoses, carb
gaskets, etc while the engine is running. Any rise in RPM
means a vacuum leak which must be fixed.
2. Compression check. You should see that all cylinders are
within
about +/- 10% of each other. My number 6 cylinder was 50% of
the others - in my case this meant that the head gasket was
blown. The DPO had installed the head gasket upside down. DOH!
3. Disconnect and plug the hoses between the carbon canister and
the carbs. If the engine idles much better, your anti-run on
valve is likely stuck open or miswired.
4. Pull the valve cover vent hose while the engine is running.
You should see little, if any, vapor coming from the vent.
A steady stream, or worse a pulsating stream, of vapor
indicates
blow by. You should have picked this up on your compression
test if it is bad enough. Be certain that you plug the hose
when you pull it off the valve cover, as it will create a
large vacuum leak if you do not.
5. Test the EGR valve by gently pushing up on the vacuum
diaphragm
while the engine is idling. The engine should stumble or stall.
If there is little change, suspect a sticking or dirty EGR
valve.
Let us know what you find.
Vance
-----Original Message-----
From: owner-6pack@autox.team.net [mailto:owner-6pack@autox.team.net] On
Behalf Of oliv7219@bellsouth.net
Sent: Thursday, April 08, 2004 6:16 PM
To: 6 pack
Subject: What to do next ?
History: 74 TR6 52000 mi. set up 4 years. Valve job, Carbs
sent off and rebuilt.
Problem: Will only stay runnig with both carcs @ full choke.
Question: Can anyone suggest what i might Check.
74 TR Butch
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