Re: AMC_Eagle stalling situation

["Jim Blair" <carnuck@xxxxxxxxxxx>]

I'm forwarding my reply to the list. Maybe someone can think of something 
else, or possibly make use of my posted ideas to cure their own ill running 
troubles.


A: It only stalls when you come to a stop, right? I was thinking about your
stalling trouble and the best way to test it is to use a vacuum gauge to see
if you have a leak or not. Too much gas dumping at idle will cause a shut
off (float too high) Any shop that could take that long to remove the
manifolds and NOT have them planed or at least checked for flat shouldn't be
in business in MNSHO! You need to find a Jeep repair shop.
   Is the cat clogged? That would cause a backup of pressure that the motor
can't overcome. It can be tested by unscrewing the O2 sensor and going for a
noisy drive. No stall = clogged cat. (you could also put a gauge in the hole
to see how much backpressure there is) If the cat falls apart, the pieces go
into the muffler and cork it like a bottle. (happened to me several times on
various Jeeps and Eagles) High flow cat will take the place of the OEM one,
and the AIR junk can be trashed in every state but CA. (They still require
it, even though it comes with a CARB certification tag for the removal of
the junk tubes)
   Fuel pump, or more likely crap in the fuel line can cause this trouble.
The fuel sock in the gas tank could be collapsed from MTBE fuel additive (it
turns plastic to mush and rubber hoses become piccolos!) I throw away the
stock in tank screen and just put a piece of hose on the end (to make it
reach all the way to the bottom) and cut the fuel hose just before the fuel
pump and put in a see-thru filter (put it where it won't get broken and it's
easily acccessible to see if it's dirty) A fuel pressure/vacuum gauge on the
line before the pump will tell you if there is a clog happening or not
(there shouldn't be any vacuum reading unless there is a clog)
   The other thing that causes a LOT of stalls on AMC 6 cyls is the cam
walking ahead. Ordinarily they don't slide ahead, but if you get on the
brakes, the spinning inertia of the cam can allow it to slide forward, which
throws engine timing retarded and changes the cam timing somewhat. The cure
for this is to find a 4.0L for parts and get the timing cover and cam button
off it. The problem was rampant enough that AMC HAD to put a fix in the
stock motors. (Last of the 4.2Ls, post '86 to 08/'90 in Jeeps got them too)
That will cause a stall too. (If you had the timing computer that you could
plug in and map what's doing what with RPM/inertia forces, you could tell
for sure)
   It's the idle pickup tubes, not the Venturiis that get clogged. I did a
http://www.google.com search for BBD fix and came up with Terry Howe's fix
http://www.jeeptech.com/engine/carter.html
   If your motor is overheating, then I would look more seriously into the
head gasket problem. Too bad the Holley Projection kit for AMC 6 cyls costs
so much. What would be nice is a wiring harness (universal) to attach the
Renix BBD EFI to AMC 6 cyls with junkyard parts. The HO conversion kit is
available from Jeep still (although they stopped making it, there are still
a few available) but the intake won't fit against the brake booster in the
Eagle. (The Renix one will)



Todd wrote:
So, I got my car back from my new mechanic. It was 5.5 hours for an
intake manifold gasket replacement. The worst part is that it did
not fix the stalling problem. Know he tells me that the head, intake
manifold, and/or exhaust manifold are warped and need to be replaced
or machined at a shop. I decided against leaving my car there. I
also needed the air inake check valve replaced. I told him they do
not make the original part but instead a universal type. I even told
hoe to replace it and install the new one based on a reply from this
forum. I took a look when I got home, he rerouted it some where, I
don't know where it is.

Some questions:
Could the fuel pump be the problem?

On another AMC forum, someone commented on the venturi nozzels in
the carb, has this been sucessful to others? If so, any advice for
replacement.

I tried a mechanic since I felt I did not have the time to do it
myself, from know on I will find the time.

Todd M.