The advice from Jarrid is all correct. Check that throat for signs of
dribbling with engine off and pump ON.
Any make carb has the same chance of a leaking needle valve, allowing
excessive fuel into the mixture and idle as well as at speed.
From the little you gave as diagnostic data, I assume the car idles
slow and normal when cool or warming up but after a good run and full
engine heat is developed, you have to keep it about 1500-2000 at idle
or it will stall out.
This a classic sign of too much fuel flow but .....other things need
checking as well.
1. Test fule pressure with a proper gage. If the pump is making more
than 2.0 psi, put in a regulator and set to 2 psi.
2. The need to rev up at idle CAN be caused by an obstruction in the
idle jet which starves the engine. You manage to keep it going at
1500+ because you are bringing into play, the high speed main jet
action and this supplies the engine enough fuel to avoid a stall out.
Why this would occur only when warm....is something to check out,
possibly a loose carb section or air leak which gets worse as parts
expand??
3. Check intake manifold gasket and torque carefully. Again,
expansion when hot causes changes.
4. Check timing to assure ign. is not sticking advanced when hot.
5. If PCV valve is used, see that it is not sticking open when hot.
6. If serious overheating is occuring, this would affect hot idle.
Check coolant temp for normal range operation.
7. Dirt inside carb may float around and lodge in jet or passageway
or needle valve...flooding carb or starving carb system according to
where it lands.
8. Torque everything which relates to intake and carb. Look for air
leaks but using a oil squirt gun to blow a LITTLE fuel around carb
gaskets and manifold joints. If any is inhaled via a suction leak,
the rpm will change. Of course BE CAREFUL and also have an
extinguisher close at hand in case of accidental flare up. When done
slowly, this should never occur.
9. Water or contamination in carb or fuel supply can also upset idle
at times.
10. Check that enrichment device is actually FULLY OFF when moved to
that mode. It may be working itself back to a richer setting due to
vibration or other causes. Also it may NOT be turning off in the
first place and this means the hot engine is running choked...and
won't idle slowly !
Hope some of these tips will allow you to find your problem and I
await your report as to just what was found wrong.
-----------------------
Joe K.; the pitman arm seal is in fact a metal rim lip seal similar
to trans and axle seals. You pull off the pitman with a proper gear
puller or steering puller (no hard beating allowed here).
Use a small hook tool to lever out the old seal. Contact Barry
bearing Co. or similar jobber for anti-friction bearings and show
them this seal. They will find it is a std. inch size seal...no sweat.
You must of course get a seal which is "close" to the original as far
as fitting the pitman shaft dia. but even here the lip of any seal
can accomodate a bit of range as long as it is not distorted out of
its notmal ride shape. The height of the seal as well, can be a bit
taller than the original.
Clean up the housing with fuel or solvent to make the seal seating
surface as dry as possible. Then give the OUTSIDE and TOP of the seal
a thin coat of Permatex Blue silicon rubber sealant or equiv. product.
This lip seal works with the lip upwards against the oil source.
Use a well fitting tube or device to press and tap this seal squarely
onto its seat, replace washer below it and then put the pitman arm
back on the spline, using a brass or lead hammer to get it up almost
all the way. Then put on the nut and torque up to the 75 lbs. put in
cotter pin!
Dick T.
This archive was generated by hypermail 2b30 : Tue Sep 05 2000 - 09:56:55 CDT