the DODGE CUMMINS 5.9L (1994-1998)
Reported 12 Valve
- Throttle Problems - NOTE: Recall
970 should eliminate these problems for 94-95 models
- Frayed or Broken Throttle cable
- Symptoms: High idle speed, loss of throttle control, low power
- Look for broken strands on exposed steel cable at injector pump
- Original cables had a 30,000 mile life
- Replacement cable is a new design - life unknown
- Throttle Cable Replacement instructions
- Insufficient throttle travel
- Symptoms: Low power, engine does not pull well above 2200 RPM
- Caused by stretched throttle cable, throttle rod out of adjustment,
worn throttle parts
- Check by having someone hold the accelerator pedal to the floor
while you see if the throttle bellcrank on the rear of the injector
pump will move farther by hand.
- Temporary fix: replace the small spring at the end of the throttle
cable where it connects to the accelerator pedal under the dashboard.
Unwind the short spring from the cable, install a longer spring, wrap
it with a piece of tubing, and put a small hose clamp around the tubing
to keep the spring from flopping over.
- Broken throttle springs
- Symptoms: Inadequate/No throttle return when pedal is released,
high idle speed
- There should be a double spring extending from the throttle lever
on the rear if the inj pump to a bracket near the power steering pump.
- Temporary fix: Use a generic throttle return spring from an auto parts
- Worn throttle rod parts - photos parts
- Symptoms: Throttle binding, high idle speed, loss of throttle control
- Temporary fix: Use tape or a tie-wrap to keep the socket on the ballstud.
- Foot pedal (throttle) tends to bounce resulting in bucking or jerking.
- 1994-96: engines add a spring (part no 3933130) inside the existing
injector pump throttle return spring.
- 1997 engines replace the spring closest to the drivers side fender
with part number 393131.
- 96-98 engines TSB
18-29-97A replace throttle lever assembly (also, see below
- 1995-96 vacuum component failure - brake system, A/C, cruise control
problems may be caused by oil in vacuum lines. See D--97-10
for 7 year/unlimited mileage warranty extension for components affected by
- 1997 vacuum component failure - 97 models have a revised check valve,
but they are failing after 4 years. No extended warranty coverage is offered
for 97 models.
- 96 CA Diesel with "EGR SYS Failure" code - TSB
18-25-97 Reprogram PCM
- Erratic automatic transmission shifting, truck jerking under load
- All pre 1998 models use a throttle position sensor
- The TPS connector can loosen or corrode. Check carefully, bend and coat
pins with dielectric grease.
- The TPS is bad. Replacement is the only option.
- Low power and/or poor fuel economy
- Check first for a plugged catalytic converter , fuel filter, or air filter
- From: DYNOOMAN@aol.com - I see a lot of
low horsepower problems due to Excessive idle time's and plugged cat's...
- Check for loose or cracked boost line to the AFC housing on the Injector
- If diesel produces clouds of white smoke when first started, check fuel
- Defective Injector Pump Fuel Overflow Valve (Diagnosis
- Defective fuel shutdown solenoid can restrict fuel supply.
- 1991-1992 TSB 18-11-92, LDA Starwheel
- 94 TSB 18-10-94A
- check engine timing
- 94+ TSB 14-07-96, Check fuel pressure
- Turbo diagnostics - Star Center
- 94+ Check for a turbo/wastegate problem - TSB
- 94+ Wastegate testing and repair - TSB
- 96 Revised injection timing for CPL 2022, or 2023 - TSB
- 94-95 Acceleration tests, throttle linkage adjustments, fuel pressure
tests - TSB 18-29-95
- Fuel pre filter screen clogged - screen should be checked every 24,000
- Rough Idle and low power.
- Excessive White Smoke
- 1994 engine s/n before 56148586, TSB
18-10-94A correct timing to 12.5 degrees
- Low fuel economy and/or fuel leakage
- Fuel return hose behind the fuel filter has a reputation for failure and
- Reported by several people including myself! Rams over 3 years old:
- Regular fuel hose has a short life, use fuel injection line.
- Metal low pressure return line from the overflow valve cracked.
- Hard to start, no start, low power in cold weather:
- Whine or howl at highway speed
- TSB 11-01-97
- replace muffler with Part# 52019324AB
- Some exhaust brakes will produce a moaning sound at certain engine speed
and load conditions
- Excessive Turbocharger Noise
- Voltmeter jumps up and down - Normal, caused by intake manifold heaters
cycling when engine temp is below 60 degrees.
- Voltmeter low, battery not charging
- Intake heater stuck on (diagnosis page)
- Engine speed sensor failed (the tachometer will also not be working)
- Alternator failure
- Headlight intensity flickers or changes
- Caused by intake manifold heaters cycling when engine temp is below
- If the problem continues at speeds above 18 mph, check for loose terminals
on the manifold heater relays.
- Wide fluctuations of the temperature gauge
- the result of a large radiator, it is relatively harmless and normal
- Cummins has released a revised T-stat that does fix the "problem".
The revised T-stat Cummins part number is 3934373. (The old T-stat Cummins
Part number is 3928499. )
- This solution has been reported by Gerry Willomtzer <firstname.lastname@example.org>:
195 degree t-stat Dodge PN 3418459 intended for a 1973 or so gas engine
(From Gene's Chrysler in Fairbanks www.geneschrysler.com).
- Engine overheating
- Defective viscous fan clutch - if the fan does not produce an audible
roar when the engine is hot, the clutch is not engaging.
- 1994-97 all engines with snowplow factory prep code (AHD): TSB
07-05-97 Replace viscous fan with part # 52028837AA
- Thermostat removed - the engine will overheat with no thermostat installed
- No crank with key held in start position - all 94-97 BR models &
- TSB 08-21-97
check solenoid cable connection torque
- dead battery - they die without warning
- 96-97 Speed control doesn't function or is intermittent
- TSB 08-22-97
- leaking vacuum hose at the speed control servo
- Speed control overshoots the set speed when engaged -
- Review procedure. Repeatedly engaging the speed control with little
or no throttle confuses the speed control to the point that it thinks
there is extra slack in the throttle cables, so it "takes up the
slack" resulting in overspeed. See TSB
08-16-95 Rev. A for procedure to "unlearn" the overshoot.
- Oil Leak at timing case, loud engine noise, engine miss, and (rarely)
sudden stall - All engines built before March 1998: Assembly pin in timing
case can fall into the timing gears. The pin bangs around inside the case
until caught by a gear and thrown through the case. This can also damage the
gears, camshaft, injector pump, or vacuum pump. This is a known problem that
occurs infrequently. The simplest way to prevent this is to block the pin
with a tab or bolt.
Description of bolt in housing case to retain pin.
Description of tab to retain bolt.
See TDR threads for additional details if you are a member. If not, google
"killer dowel pin" for plenty of information.
- "KDP" Killed today!
- Preventative step to trap the pin before it escapes - TDR posting: Dowel
- 98+ Ram speed control setting creeps upward - Replace faulty vacuum
Throttle Linkage and Spring
Subject: Re: throttle spring
Date: Fri, 20 Feb 98 07:34:33 CST
From: email@example.com (Keith Penner)
I looked through my receipts last night and only came up with the instruction
sheet for installing the "reduced gain throttle lever installation procedure".
It is kit # 3806215 with a bulletin #3887755-01. I do remember that it was packaged in
Chrysler wrapping so it comes from them and not cummins.
I hope this helps. The kit really fixes the throttle sensitivity problem. Also if
you are able to get this done make sure that it is set correctly. My first test drive
showed that I was not able to get full throttle range and they reset it.
Keith Penner firstname.lastname@example.org
Subject: Re: throttle springs
Date: Wed, 25 Feb 1998 16:47:31 -0800
From: bernard rate <email@example.com>
The dealer performed TSB
18-29-97 on my truck today to cure the bucking problem. They used
p/n 5011726AA and 3806215. Driving home, I could tell that more travel is needed
to get WOT.
Subject: 0 to 60 Times And Low Power
Date: Sun, 1 Feb 1998 11:47:39 -0700
From: "Matthew Stabnow"
Something you might check for your low power problems is the P7100 FIP overflow
valve. The Bosch P-type inline fuel injection pump is very sensitive to supply
pressure variations. If this pressure is low or pulsating excessively, the following
symptoms can occur:
Low RPM miss / instability
Engine dies at idle (especially when hot)
Fuel Filter cracking
You may not get all these symptoms, maybe just 1 or 2. I have the Bosch technical
repair bulletin which describes all the symptoms, testing and repair of the overflow
valve. The factory service manual also has a section on the Cummins fuel system with
the location and replacement of the overflow valve, a simple and inexpensive
procedure. Your local Cummins dealer is probably your best bet for testing and
repair of your low power complaint.
see overflow valve diagnosis info
Maximum Boost for stock Rams:
94+ 160, 175, 180 HP 15-18 PSI
Page last updated: March 7, 2008