[Lumps!] Engine Miss question

Hello all,
My 350 Lump has developed an engine miss at Idle when the gear selector
is in drive. I have the turbo 350 transmission. I have changed the plugs,
rotor, coil, cap & rotor, cleaned the carb, and everything checks out ok but
the miss is still there. Are there any vacuum lines I need to check for
the transmission? If so, where would they be?

Thanks for any advise!–
Randall Adams

I just went through a similar situation with my 350. It turned out that a
valve had dropped down flush with the keeper. Fortunately it did not drop
all the way!

My mechanic helped me work with the engine re-manufacturer and it was
covered under the warranty.

I just got it back on the road last week. I sure did miss driving it. It
was a six week process to get everything taken care of.

Matt Grimes
86 XJ6 350

Daimler Guy wrote:>

Hello all,
My 350 Lump has developed an engine miss at Idle when the gear selector
is in drive. I have the turbo 350 transmission. I have changed the plugs,
rotor, coil, cap & rotor, cleaned the carb, and everything checks out ok but
the miss is still there. Are there any vacuum lines I need to check for
the transmission? If so, where would they be?

Thanks for any advise!

Randall Adams

Randall,
Perhaps check your camshaft for a worn or missing lobe.
Some vintages of small blocks with original cams had a “soft” cam, and
prematurely lost lift on one or more lobes. Just a shot in the dark, but
worth checking, anyhow, and fairly easy to do. Just pull off the cam covers
and note the travel of each pushrod/rocker while cranking engine by hand.
This type of problem sort of sneaks up on you slowly.
Alternately, is the miss something that showed up after having work done?
If so, retrace your steps and check for vacuum leaks, etc. If memory
serves, the only vacuum to a TH350 is for the modulator, which would only
cause a miss if the line were leaking. If the modulator is leaking, you
will notice a mysterious loss of trans fluid, and perhaps tell-tale smoke in
the exhaust.
Good Luck
Dave Daisley
'81XJ 350/th350----- Original Message -----
From: “Daimler Guy” daimlerguy@NWAI.net
To: “LUMP LOVERS” Lumps@jag-lovers.org
Sent: Sunday, December 10, 2000 12:58 PM
Subject: [Lumps!] Engine Miss question

Hello all,
My 350 Lump has developed an engine miss at Idle when the gear
selector
is in drive. I have the turbo 350 transmission. I have changed the
plugs,
rotor, coil, cap & rotor, cleaned the carb, and everything checks out ok
but
the miss is still there. Are there any vacuum lines I need to check for
the transmission? If so, where would they be?

Thanks for any advise!

Randall Adams

Exactly what happend, to your beloved admin.,
about a year and a half ago…
cam had worn on two lobes (different cylinders)
Problen wasn’t with a miss tho… It just wouldn’t idle under
2000 RPM, and was hard to start.
Gee… I wonder why…

Charlie
Lumps Admin.---------- Original Message ----------------------------------
From: “David Daisley” daisley@uleth.ca
Date: Thu, 14 Dec 2000 09:44:09 -0700

Randall,
Perhaps check your camshaft for a worn or missing lobe.
Some vintages of small blocks with original cams had a “soft” cam, and
prematurely lost lift on one or more lobes. Just a shot in the dark, but
worth checking, anyhow, and fairly easy to do. Just pull off the cam covers
and note the travel of each pushrod/rocker while cranking engine by hand.
This type of problem sort of sneaks up on you slowly.
Alternately, is the miss something that showed up after having work done?
If so, retrace your steps and check for vacuum leaks, etc. If memory
serves, the only vacuum to a TH350 is for the modulator, which would only
cause a miss if the line were leaking. If the modulator is leaking, you
will notice a mysterious loss of trans fluid, and perhaps tell-tale smoke in
the exhaust.
Good Luck
Dave Daisley
'81XJ 350/th350

----- Original Message -----
From: “Daimler Guy” daimlerguy@NWAI.net
To: “LUMP LOVERS” Lumps@jag-lovers.org
Sent: Sunday, December 10, 2000 12:58 PM
Subject: [Lumps!] Engine Miss question

Hello all,
My 350 Lump has developed an engine miss at Idle when the gear
selector
is in drive. I have the turbo 350 transmission. I have changed the
plugs,
rotor, coil, cap & rotor, cleaned the carb, and everything checks out ok
but
the miss is still there. Are there any vacuum lines I need to check for
the transmission? If so, where would they be?

Thanks for any advise!

Randall Adams