hi , i have a chevy cavalier 2.2 lt 1998 auto.
it burns fuel like a log. will do only around 11 miles per galon,, the tps sensor was bad, the iac valve and the map sensor.
had real problem starting, rough starts so i changed the spark plugs that were in real bad shape, and plug cables, changed the coils about 6 months ago, it still has a misfire on cil 2. but its intermitent. not that serious, probably a bad new coil,, but it still has a rough start and have to push the gas to start, no fuel leaks, no smell,
the tps sensor was faulty cuz it was revving alone,, scanned that , changed that,, before all the replacements the car was stalling in idle.. opened th throtle by 0.5 degress , stalling stoped, , trasmission working fine.
wondering if rough start was because of something electric,, still has original ignitition module.. havent tested it..
or ckp sensor about to go .
but my scan tool only gives me a “count”reading for the ckp and cmp sensors , any idea what it means?
by the way the timig chain also changed new. , the tensioner was about to give in.,
i still have to press the gas to get it to start,, crank is fine.
scan readings
Name Value Unit
Adaptive Knock Retard 0 deg
Barometric Pressure (BARO) 13.51 psi
Calculated Air Flow 33.91 lb/h
Camshaft Position (CMP) Active
Counter 35 counts
Camshaft Position (CMP) Resync
Counter 0 counts
Crankshaft Position (CKP) Active
Counter 235 counts
Desired Idle Speed 625 rpm
Engine Coolant Temperature
(ECT) 150.8 degree F
Engine Load 43.137 %
Engine Run Time 00:08:58
Engine Speed 644 rpm
Evaporative Emission (EVAP)
Canister Purge 1.176 %
Fuel Pump Relay Command On
Fuel Trim Cell 21
Generator L-Terminal Inactive
Generator PWM 99.608 %
Heated Oxygen Sensor (HO2S) 2 451.36 mV
Idle Air Control (IAC) Position 22 counts
Ignition 1 13.4 V
Intake Air Temperature (IAT) 122 degree F
Knock Retard 0 deg
Knock Sensor (KS) Noise
Channel 1.31 V
Long Term Fuel Trim (FT) 0 %
Loop Status Closed
Manifold Absolute Pressure
(MAP) 52 kPa
Manifold Absolute Pressure
(MAP) 2.29 V
Med. Resolution Engine
Synchronize Yes
Med. Resolution Resync
Counter 0
Number Of DTC(s) 0
O2S 1 451.36 mV
Power Enrichment Inactive
Short Term Fuel Trim (FT) 0 %
Spark 14.500 deg
Throttle Position (TP) Angle 0 %
Throttle Position (TP) Sensor 0.61 V
Vehicle Speed 0 mph
Air Conditioning (A/C) High Side
Pressure 1.55 V
Air Conditioning (A/C) High Side
Pressure 895.36 kPa
Air Conditioning (A/C) Relay Off
Air Conditioning (A/C) Request No
Air Fuel Ratio 14.300 : 1
Barometric Pressure (BARO) 90.41 kPa
Desired Idle Speed 625 rpm
Engine Coolant Level (ECL) OK
Engine Coolant Temperature
(ECT) 71 degree C
Engine Oil Pressure OK
Engine Run Time 00:10:50
Engine Speed 623 rpm
Fan Control (FC) Relay 1 On
Intake Air Temperature (IAT) -40 degree C
Manifold Absolute Pressure
(MAP) 53.88 kPa
Manifold Absolute Pressure
(MAP) 2.31 V
Throttle Position (TP) Angle 0 %
Throttle Position (TP) Sensor 0.61 V
Torque Converter Clutch (TCC)
Brake Switch Closed
TR Switch A Low
TR Switch B High
TR Switch C High
TR Switch P Low
Transmission Range Park
Vacuum Calculated 36.25 kPa
Vehicle Speed 0 km
any idea of what “count” is on the ckp and cmp sensors, they go up and then back to 0. but the waveform is ok.
i suspect the ignition module might be faulty and surely one of the coils, but to only do 11miles p galon is making me crazy, i cant drive this car too far out.
is fuel trim 21 value ok for this car?
the other thing is the map value seems a bit low. it was 48 with the gm map sensor.
i just found out it has an O2 sensor, i was told this model didnt,, still dont know where it is. its suppose to go right in the exhaust manifold, but there is only a screw.
this car is rated at 23mpg, but its doing half.
it does need new rings. really like this car, so im trying to get it to shape, but its taking its toll.
really need help with the fuel problem, any ideas are welcome.
