Audi 80 Quiz
KE-III-Jetronic Injection System

Fault Finding - KE-III-Jetronic

In this manual: KE-III-Jetronic Injection System
Technical Description — 39Engines — 41Exhaust System — 13Cooling System — 28Fuel tank and fuel pump — 12Air Filter and Intake Ducts — 13Mono-Motronic Injection System — 18Digifant Injection System — 19KE-III-Jetronic Injection System — 35MPI and MPFI Injection Systems — 32Clutch — 11Transmission and Driveline — 21Suspension and Steering — 33Brake System — 41Anti-lock brake system — 8Wheels and Tires — 13Body Electrical System — 35Ignition System — 24Lighting — 14Signaling Devices — 7Instruments and Auxiliary Equipment — 54Heating and Ventilation — 7Body Components — 18Troubleshooting — 6Specifications — 13
~2min read

Malfunction Possible Cause Remedy
A. Engine does not start when cold 1. Pressure regulator does not regulate pressure to the plunger filling port or does so incorrectly
2. Faulty idle stabilization control valve
3. Cold start valve does not inject fuel
4. Cold start valve leaking, defective gasket
5. Shut-off valve installed incorrectly
6. Shut-off valve or control plunger sticking
7. Unmetered air entering the engine		 Have the pressure regulator and control unit checked at a workshop
Check

Check the cold start valve
Check for leaks

Check installation
Check
Check all lines and flange connections
B. Engine does not start when warm 1. See A 1, 5 and 6
2. Injectors leaking, opening pressure too low
3. System pressure too low
4. Mixture too rich at idle
5. Mixture too lean at idle		 Check (at a workshop)
Measure at a workshop
Adjust CO content at a workshop
Adjust CO content at a workshop
C. Engine runs rough at idle when cold 1. See A 1, 2, 4, 5 and 7
2. See B 2
D. Engine hesitates during acceleration when cold 1. See A 3
2. Faulty throttle valve angle sensor		 Check
E. Warmed-up engine shakes at idle 1. See A 1, 2, 6 and 7
2. See B 4 and 5
F. Backfiring in the exhaust manifold 1. See A 1
2. See B 5
G. Popping in the exhaust manifold 1. See A 1 and 4
2. See B 4
3. Fuel pump not working		 See chapter «Fuel Tank and Fuel Pump»
H. Engine runs unevenly, stalls 1. Fuel pump running unevenly
2. Fuel pressure in the system not within specification		 Measure fuel delivery rate at a workshop
Measure and adjust at a workshop
I. Insufficient engine power 1. See A 1, 4, 6 and 7
2. See B 4 and 5
3. Insufficient fuel pump capacity
4. Throttle valves do not reach full-throttle position		 Measure fuel delivery rate at a workshop
Adjust the throttle cable or check the connection to the throttle valves
J. Engine continues to run after ignition is switched off 1. See A 4, 5 and 6
2. See B 2
K. Fuel consumption too high 1. See A 1 and 4
2. See B 4
L. Engine idles too fast when warm See A 2

Test yourself

A quick Audi 80 quiz: every answer comes with an explanation and a link to the manual page.