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From: [e-mail] (Dr. David Zatz)
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Subject: rec.autos.makers.chrysler FAQ, Part 4/6
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Organization: http://www.allpar.com
Summary: Idle, stalling, power, mileage, transmissions
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PART IV - Engines: Idling, power, stalling, mileage; transmissions

There is a separate Neon FAQ.

Also see:

Part 3 - Classic cars
Part 5 - Funny noises, oil leaks, temperature stuff
Part 6 - Other stuff

* Many problems are caused by poor battery connections to the cables,
  which can cause signals to the computer to be incorrect. Check and clean
  the battery terminals and cables first!

* If your antifreeze was just changed and your car started to overheat,
   purge the system of air bubbles.

* Additional information on troubleshooting and repairs is on
  the web site at http://www.allpar.com/

** Index **

Note: there are *several* entries for some problems. Try using the "search"
 or "find" feature of your word processor, or browse through the entries.

We have eliminated some relatively uncommon entries.

1.   Stall/hesitation/sag
3.   Idle speed jumps OR Intermittent idle speed problems (2.2/2.5)
      *** (see also #28 and other items)
4.   Transmission noise: when shifting/stopping, buzzng/ratcheting
6.   Fast idle on startup
8. Knocking
9. Gas mileage / rough running easy fix
12.  Computer code 13 (MAP sensor) - engine runs rough (see #15)
15.  Cold / freezing weather problems
16.  Hard to shift in cold weather
17.  2.5L engine knocks/ticks; poor cold idle
22.  Other transmission issues
23.  Metallic banging during 2-1 downshift when stopping
26.  Harsh 2-1 downshifts
27.  Rough idle - mod 1/96 - several causes
28.  Idle speed increases / engine races sometimes / erratically
         (see web site).
30.  Power loss, stalling, and/or rough running
33.  Power drops dramatically (engines with carb - esp 2.6)
        / icing of carburetor and other parts
37.  Magnum V-6 engine problems
41.  Power drop, black smoke, 2.6 liter
43.  TBI engine hesitation (2.2/2.5)
44.  Power loss/jerky on acceleration
45.  Turbo engine cutout/power loss: See web site.
47.  Hesitation (see related topics above)
48.  3.9 liter (pre-1993) common problem - PREVENT IT
49. Turbo cutting out / power loss light
50.  Jeep 4.0 stalling
54.  Hesitation, 3.0 liter V-6
73.  Transmission clunk / rough downshift or shudder
77. 3-speed automatic flare-up / slow 1-2 shifts
80. Power loss or gas mileage loss
82. Poor mileage, cold starts
83. Mitsubishi 2.6 cold start / drivability

1. Stall, hesitation, or sag

See http://www.allpar.com/fix/stall.html for a full list.

---------------------------------------------------------------------

3. Intermittent Idle Problems: (see also #28, #30)

Problem: on 84 Laser, 88 Omni, and 87 Shadow (2.2 liter, turbo and
non-turbo), idle suddenly jumps from 800 rpm to 3000 rpm. Sometimes goes
away quickly, sometimes doesn't. Solution: turning off the defroster; check
the speed/distance sensor and connection  (Tom), freon level in the a/c
(james eldridge), and the wiring harness on the back side of the engine
(Jeffrey Wieland). Jeff found that the wiring harness got hot enough to
damage the wire insulation; he spearated and re-insulated the wires, which
fixed the problem.
 **********
High idle, 2.2/2.5 TBI:

Most likely automatic idle speed system.  Check for fault codes.  Check
wiring harness near AIS motor for shorted wires or wires that seem stuck
together (separate and insulate from each other).  Also check EGR system,
vacuum system, and timing.
------------------------------------------------------------------------
4.   Transmission noise: when shifting/stopping, buzzng/ratcheting

Bob Meyer wrote about the Stratus (Cirrus/Breeze)'s automatic transmission
making a buzzing/ratcheting noise when shifting gears or pulling to a stop.
He said this noise, which also occurs on the Acclaim and other cars, is
normal and comes from the solenoids. It is most noticeable from outside the
car. He warned that a continuous buzz or whine could indicate low fluid or
a bad pump, "But if what you're hearing is only during shifting from park
into reverse or drive or coming to a stop, then the dealer is probably
telling you the truth."
------------------------------------------------------------------------
6. Fast idle on startup

(Bohdan Bodnar): This is normal for [some] Chrysler products.
The throttle body temperature sensor is used ONLY during hot
restarts;  during a hot restart, it is the dominant temperature sensor for the
first 10 seconds only.  So, if the engine runs funny for almost exactly 10
seconds during a hot restart, consider cleaning the contacts of that sensor.
------------------------------------------------------------------------
------------------------------------------------------------------------
8. Knocking

The knocking could be caused by low oil pressure.  You'd probably want to
have this tested.  It
is possible to replace the stock oil pump with a "high flow" pump which
will alleviate this
problem (or, rebuild the engine). - Bohdan Bodnar,

------------------------------------------------------------------------
9. Gas mileage / rough running easy fix

Vaughn Smith suggests that, when you replace your rotor ($6 at a dealer),
you clean the Hall effect pickup (just under the rotor, you can't miss
it!). This helped him quite a bit on three cars.  Be careful to put it back
the exact same way it was when you took it out! Also clean under and around
it.
------------------------------------------------------------------------

12. Engine runs rough - computer shows code 13

From: Jizhong Wang - 84 Dodge 600 ES
A couple of months ago the car stalled with the "Power Loss"
light. My computer said it was MAP sensor vacuum circuit (code 13). I took the
car to a dealer and was told my computer was faulty - didn't replace it.
Later I found a 6-way connector was loose. It was AIS motor and TPS
sensor connector, nothing to do with MAP sensor. Check the
connections and vacuum leaks before you replace it. BTW, my MAP
sensor is under dash of passenger side, inside the car. It is
two inches above ECM.

<Thomas Z. Zeeb> adds: on Caravan/Voyager, it is under the hood and screwed
into the firewall, just off center to the left, above and behind the belts.
It has one vacuum hose and one three-node electrical connector attached to
it.  They range from $70 -$100 US at the dealer.  If the MAP is shot, the
engine will shut down after starting.  Try disconnecting the MAP, the
engine will then run (rough) in some models.
------------------------------------------------------------------------
------------------------------------------------------------------------

15. Cold weather problems

Glen Larche said a MAP relocation kit is available to prevent problems
in freezing temps (rough cold idle, stalling):
Kit for turbo vehicles- 4419402
Kit for EFI vehicles- 4419401
------------------------------------------------------------------------
16. Hard to shift into reverse (manual transmissions)

francini sez this problem is common to cars which have
nonsynchronized reverse gears. Shift into a forward gear before going into
reverse. Or wait a
few moments before shifting into reverse, after hitting the clutch, so the
engine shaft stops spinning.
------------------------------------------------------------------------
17. 2.5 liter knock/idle

(Janos Schumacher) says: "A 2.5 is a stroked 2.2 so the skirt of the piston
goes past the bottom of the cylinder.  This makes the piston wear away at
the cylinder walls making them slightly oval.  The noise you are hearing is
known as piston slap and the only solution is to turn up the radio.  Once
the car warms up the cylinders become more round and the noise goes away."

Chrysler's service bulletin says: Cold engine knock a few seconds after
startup, lasting 3-5 minutes -- most noticable at 2,000 - 2,500 rpm. Sounds
like valve lifter or tappet noise. Loudest in colder weather. Usually
disappears when the car is
warm.
OR
Cold idle rough util coolant reaches 50-60 degrees F.
  -- TSB 09-06-93 provides for computer replacement.
------------------------------------------------------------------------
------------------------------------------------------------------------
22. Other transmission issues

See http://www.allpar.com/fix/trans.html
------------------------------------------------------------------------
23.   Metallic banging during 2-1 downshift when stopping

Jim Zimmerman had this in his Caravan. There is a TSB, but the dealer said
"you have to complain LOUDLY." The service guy called it the 'post shift
bang' "
------------------------------------------------------------------------
-----------------------------------------------------------------------
26. Harsh 2-1 downshifts

TSB 21-16-93 covers "harsh 2-1 downshift" on the 41TE transaxle, the
four-speed auto in most CC cars from 1989-1992. The change is replacing
the transmission control module (3.3, 3.8, or 3.0 liter engine only).
-----------------------------------------------------------------------
27. Rough idle - several cases

Switched from Getty and Citgo gas to Mobil, Amoco, and Gulf.
Made a tremendous difference.

EGR valve may be stuck open or rusted off.

Engine idled erratically when warm, sometimes lost power after first
response when accelerator pressed about 1/3-1/4 down. Dealer first
adjusted venting at gas tank, seemed to help the idle. Then cleaned and
sealed the battery connector, solving the problem; was probably bad
battery connection causing system voltage fluctuation, which caused
changes in the controls. (Mustafa Soysal) (edited)

My car died slowing down...I disconnected my EGR backpressure transducer
from the vacuum lead.  Now my car is a little bit more stable at idle,
better gas mileage, most likely can't pass emisions. (Jeffrey Paul
Chojnacki) - note: others warned against disconnecting EGR; there may
have been a leak in the EGR system.

My 1986 Le Baron engine's CTS's connections had corrosion on them (a scan
tool showed that it took a long time to reach 180F and that it NEVER went
above 180F during highway driving); I opted to replace the CTS and
connector.  Cold start problems went away and fuel efficiency improved.  No
fault codes.

If you have hot restart problems which disappear after 10 seconds
of engine running, use tuner cleaner on the throttle body temperature
sensor's connector and see if the situation improves.  (Bohdan Bodnar)

Dave says: try the basics. Replace the rotor ($6), distributor cap, wires
(silicone coated lifetime warranty name brand=$20 mail order!), and clean
and regap the plugs.
-----------------------------------------------------------------------
-----------------------------------------------------------------------
-----------------------------------------------------------------------
30. Power loss, stalling, and/or rough running

I have an 87 Sundance 2.2 which has 130k miles and runs great. It
had power loss, stalling, rough running; replaced the $20 MAP sensor
(passenger side fender well) and fixed it. First time it went bad, did
not show up on dealer computer. (Phil McClay)

Tach danced around, engine sometimes stalled. Solution: the computer
(SMEC)'s grounding wire was loose, causing the computer to go nuts. The
wire leads from the computer to a ring connector bolted onto the engine
block at the air filter housing. Clean the corrosion off of all parts.
(David Schmitt)

Ron Smith's 1986 Lebaron GTS was stalling after warmup and not restarting.
The fuel pump was worn out.
-----------------------------------------------------------------------
33.   Power drops dramatically (engines with carb - esp 2.6)

In cold weather, some vehicles with the 2.6 liter 4-cylinder engine may
have severe power loss (e.g. after running about 20 minutes between 60 and
65 mph). If one steps on the gas, black smoke may come out of the tailpipe.
The solution  (from Dave Witte): A de-icing kit to heat the intake air
enough to prevent freezing. SOME engines had this kit at the factory. The
kit is not expensive.
---
My manual shows that the 2.6 had a carb air heater.  The tube that comes up
from the exhaust manifold, will be on the back side of the engine, and hard
to reach.  When the engine is cold, make sure that the vacuum actuator in
the air horn leading to the air cleaner housing is working. In cold
weather, with the engine cold, it should redirect all of the air flow
through the stove on the exhaust manifold. (Jeff Wieland)
---
The problem was freezing of the carb. and the answer was to moved the hose
that feeds outside air to the air filter compartment and position it
somehwere to the rear of the engine.  This prevents the outside cold air
from making its way over to the carb.(Ken)
-----------------------------------------------------------------------
------------------------------------------------------------------------
37. Magnum V-6 engine problems

Problem: 1992 Dakota 4x4 with Magnum V-6. Engine faltering badly
sometimes when cold, sometimes when hot.  On cold starts, the engine
will sometimes act as though it's getting gas only at idle, won't
accelerate.
It will cough and sputter awhile, then "catch" and take off, running
fine from then on.  Other times, it will "skip a beat or two" at speed,
under mild acceleration.

David Wright: Some Magnum engines came with "mis-phased" distributors,
causing  intermittent missing.

Jerald Barker: Replace the back pressure transducer and EGR valve. The
Back Pressure Transducer lies next to the EGR valve just above the left
valve cover.
------------------------------------------------------------------------
------------------------------------------------------------------------
------------------------------------------------------------------------
------------------------------------------------------------------------
41. Power drop, black smoke, 2.6 liter

>After running for about 20 minutes the power drops out to the point
>where I have to pull over. If I am in "Park or Neutral" and step on the
>gas pedal, black smoke comes from the tail pipe.

With 2.6L engined minivans ... the airflow goes right
over the carburetor ...  freezing it solid.  Seconfd you stop, engine
heat thaws it out (which is why  you can stop, restart, and it seems a
lot better). I put a metal shield in front of the carburetor
to deflect wind around it and it worked. -- Jonathan N. Deitch
------------------------------------------------------------------------
------------------------------------------------------------------------
43.  TBI engine hesitation (2.2/2.5)

2.5 liter, TBI: Intermittent engine hesitation under high speed driving
ONLY or under moderately high speed and heavy acceleration.  The problem
NEVER occurs during moderate driving or heavy acceleration at low to
moderate speeds.

The brass pin you see from the top of the injector -- they didn't make it a
tight enough fit.
Eventually the
pin begins to back out and the ECM keeps shortening the injector pulse
to compensate for the change in mixture. The process can take several
months before it produces symptoms. The pin
backs out to a point that the ECM can no longer compensate for and you
get driveability problems. (dotto)

First check fuel pressure, around 14.5 psi engine off (using DRB in
actuator test)  I have seen the distributor pick-up unit on these
cut out intermittently.  When the computer loses the signal from the
distributor, it shuts fuel/spark off.  The Hall-effect plate tends to get
loose.  One TSB
involves re-locating the MAP sensor from the logic module(right kick panel)
to the right strut
tower.  EGR failures are also common.  They sometimes get stuck
open and  cause hesitation; try disconnecting the vacuum hose
from the  EGR valve.  The car will probably ping on acceleration, but
hesitation  should cease.  The valve is located on the driver's side end
of the  exhaust manifold.  You may have to remove the air cleaner
housing to see  it.  Faulty TPS sensor can cause this type of problem.
It may have a  "dead spot"  (Eric Eleazar)
------------------------------------------------------------------------
44.  Power loss/jerky on acceleration

Turned out to be the fuel filter (86 Aries 5-speed, 2.2).(Dave) (89
Aries, 2.5, after 1/2 hour car jerks, fine on short drives): it would
falter. The dealers (all
13 I went to) replaced the map sensor, crank sensor, cam sensor, spark
plugs, spark plug wires, turbo
boost solenoid, egr valve, pcv valve, and just about every other gadget...I
found a dealer who knew something, and they fixed the problem in under an
hour.  The plug wires had been installed incorrectly. (jnoyes)
------------------------------------------------------------------------
------------------------------------------------------------------------
47. Hesitation (also covered elsewhere)

Problem: 2.5 engine hesitates/sputters/lurches for a second now and
then under normal driving conditions (highway, cruising, foot steady on
gas). Reason: plug wires were going bad. (Paul F. Schikora )

Problem: hesitation/lurching. Solution: fouled plugs. Oil fouled plugs
may indicate serious problems or just bad PCV valve.

Problem: 3.0 V-6 bogging on acceleration. Solution: clean the throttle
body if it has gumming or varnish. You may have to clean the throttle
plate edges with Scotch Bright pads and clean the bore using a good
carburetor spray solvent.
------------------------------------------------------------------------
48.  3.9 liter (pre-1993) common problem - PREVENT IT

My 1992 Dakota 3.9L needed a new timing chain and gears
at 49,000 miles.  This was originally diagnosed as "mis-phased"
distributer, and "fixed" to some degree.
...
According to one of the service managers, the 1992 Magnums had a
"single roller" roller chain.  The 93+ engines have the more typical
double roller.  This may be a common problem for the pre-93s.

The misfiring had been happening sometimes on upshifts, but worsened as
performance sagged. The misfiring occurs when the rotor gets enough out
of phase that the spark gets fed to the wrong cylinder. Ignition timing is
not changed by this
problem, valve timing *is*,
and distributer rotor "phase" is.  Get it fixed SOON. (Ron Luse)
------------------------------------------------------------------------
49.  Turbo cuts out/power limited/power loss light

Under hard acceleration, the engine would cut out, rock like hell and
the check engine light would come on (until I released the pedal). (2.2
turbo) It turned out to be a  disconnected vacuum hose to the wastegate
assembly. (Ralph J. Zottola) If the wastegate is not
opening, the turbo will overboost, the the computer will cut the fuel.
As the RPM decreases, the boost lowers and the fuel comes back on. (Mac
Alan Crossett)
------------------------------------------------------------------------
50. Jeep 4.0 EFI engine stalls at a stop (Jeep 4.0 stalling).

The problem is the flywheel sensor.  It is located by following the
wires from the along the firewall and along the bellhousing. These
sensors get worn out from debris and it also might be just the
wires going to it. I had the same problem and took it to a dealer
and they couldn't figure it out either. (Ken Talley)
------------------------------------------------------------------------
--------------------------------------------
54. 3.0 V-6 hesitation or bogging on acceleration

Check throttle body for gumming or varnish. You may have to clean the
throttle plate edges with Scotch Bright pads and clean the bore using a
good carburetor spray solvent.
--------------------------------------------
--------------------------------------------
73.  LH transmission clunk / rough downshift

(Blair Wetmore)'s dealer reprogrammed the 4-speed
transmission's computer to cure the shudder when the torque converter locked up
under light throttle. Downshifts at low speeds are much better.

(Vincent Paul) notes that there is a TSB on other four-speed
automatic transmission shudders and mis-shifts.
--------------------------------------------
--------------------------------------------
77. 3-speed automatic flare-up / slow 1-2 shifts

profgmby and Wayne Taylor both had vehicles with 3-speed
TorqueFlites. In colder weather the engine flares or shifts slowly during
the first few hundred yards. profgmby says this causes no problems and has
over 150,000 miles on his.
--------------------------------------------
--------------------------------------------
80. Power loss or gas mileage loss

Vaughn Smith's 2.5 was losing power and mileage. While replacing a burnt
rotor (one thing to look at), he took off the Hall effect sensor. He saw
that it read when each "vane" on the distributor shaft passed the pickup
point; the inner surface of the vane, though, was extremely dirty. He
replaced the rotor and cleaned the vane, and found that gas mileage and
power increased. He also found this problem on a 2.2 TBI and a 2.2 Turbo,
with some improvement in each case.
--------------------------------------------
--------------------------------------------
82. Poor mileage, cold starts

George Lobay's 2.2 TBI had poor gas mileage, poor cold starts, and codes
17, 22, and 52. The cause was a bad connection in the circuit to the
coolant sensor, causing the computer to guess the engine temperature (high
idle). The cure: cleaning near the coolant sensor connector, on the round
6-position connector in behind the battery; and on the bulkhead connector
on the driver's side. Then check voltage at coolant sensor (leave it
connected, just skin a bit off the insulation of each wire and tap in with
your multimeter) it should be somewhere in the 3 Volt range. If that
doesn't do it the only connector left is the one on the computer. Note:
don't forget that if you remove the computer connector you must re-grease
it by Chrysler procedures.

--------------------------------------------
83/ Cold start/initial run problem - MMC 2.6

(Courtesy Marvin Stockman) The Mitsubishi 2.6's carburetor choke pulloff
tends to break; the only fix is a $700 replacement.  I have made a  twisted
loop (like a hangmans noose) of soft metal wire and place the noose section
around the stud that holds the air cleaner duct. I let the twisted straight
section hang down into the throat of the carburetor.  I try to get the wire
as close to the wall of the carburetor as I can.  This has the effect of
preventing the choke plate from closing completely, and eliminates any cold
running problem.  It is important to use thin wire ( I used soft aluminum
wire) in order to keep the opening small, otherwise the initial idle is
very high.  Another solution would be to drill a small hole in the choke
plate.  During very cold weather, I pump the accelerator 4 to 5 times and
the car starts right up.
--------------------------------------------

--------------------------------------------

For more, visit http://www.allpar.com/ - trouble, fix, help, and EEK!
sections mainly