I have a Daewoo Matiz 2001. The yellow Engine light came on a while ago and it missed a lot and then simply cut out completely at times. After a few weeks it didn't want to start at all any more. We replaced the airflow sensor , and now put in anothe distrubutor , because the diagnostics showed that the problem was on the sensor in the distributor. We also did a service on the car and checked the petrol pump. We got it back for the shop , but now it still misses , but only in 1st , 2nd and 3rd gear. When it is put oin 4th gear it runs 100%. When it idles the idling goes up and down , but if it is a timing problem it would not only miss in certain gears. would it? Any advise on what may cause this problem.?
The fact it only has a possible misfire in the first 3 gears,
tells you your under a high vacuum load getting up to speed
& applying more gas pedal command as well, until you let up
in top gear
Timing is engine load related, so your theory is not valid there either
I would do a cylinder leak down test to check the mechanical condition
of the motor,valves & such,then use an evap smoke machine to test
intake,exhaust & evap system for vacuum leaks
What about EGR System Even electronic ones use vacuum,thus
my vacuum load theory.
Get rid of all ignition misfire issues
No Vacuum Leaks anywhere on car
New upstream O2 Sensors or scope yours for
switching times
Check timing belt for issues
I guess you checked fuel pressure
Check alternator for bad diodes
Need a scan tool to look at fuel trim & all data
on a road test
Basically you missed something
SOURCE: 99 hyundai accent engine surges and dies at start when cold
There a lot of cuses for this but you need to scan the vehicule before to know what sensor is having troubles, if is too much expensive the scan in your city consider to buy one. I see in ebay a lot of types of OBD2 scanners for $25-30!
SOURCE: slight miss in engine, hard shift from 1st to 2nd long 2nd gear
Check both O2 sensor(s) and catalytic coverter.. P0420 means catalyst below threshold. Also check the sensor at the transmission and solenoid.
SOURCE: 1992 honda accord stuck in 4th gear
TCU (Transmission Control Unit) Located behind the Passenger Kick panel. it will have a burnt diode inside and can be purchased on ebay for about 79.00 with exchange.
Lugnut61
SOURCE: Renault Megane Scenic 1.6 petrol jerking in 1st & 2nd.
check hoses for splits...i had the same problem.
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