Poor cold running
11-30-2002, 04:47 AM
#1
2nd Gear
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Join Date: Jan 2002
Location: Malta
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Poor cold running
Hi
I have a 928S Euro 4664cc with K Jetronic CIS
Only problem I have is that when the car is cold is runs very rough, below 2000 rpm is seems to miss and run badly, over that its fine, also when warm car runs well.
One thing I noticed is that the revs dont fall as quickly as they used to when you lift off they drop quickly to 2000 then fall slowly down to idle
Any help appreciated
I have a 928S Euro 4664cc with K Jetronic CIS
Only problem I have is that when the car is cold is runs very rough, below 2000 rpm is seems to miss and run badly, over that its fine, also when warm car runs well.
One thing I noticed is that the revs dont fall as quickly as they used to when you lift off they drop quickly to 2000 then fall slowly down to idle
Any help appreciated
11-30-2002, 02:30 PM
#2
Matte,
It's possible your cold start system is malfunctioning and staying on too long. Have you checked the thermotime switch for a short? If it has shorted to ground it will cause the cold start injector to run continuously. Also, a leaking cold start injector could cause your rough running. Try removing the plug from the cold start injector a few seconds after startup. If it evens out, look for a bad switch or injector.
Dennis
It's possible your cold start system is malfunctioning and staying on too long. Have you checked the thermotime switch for a short? If it has shorted to ground it will cause the cold start injector to run continuously. Also, a leaking cold start injector could cause your rough running. Try removing the plug from the cold start injector a few seconds after startup. If it evens out, look for a bad switch or injector.
Dennis
12-01-2002, 02:41 AM
#3
Rennlist Member
Here's an additional link for more info:
<a href="http://www.users.bigpond.com/INTERJECT/KJETRON.HTM" target="_blank">http://www.users.bigpond.com/INTERJECT/KJETRON.HTM</a>
excerpt:
THE ENGINE WILL RUN SMOOTHLY, after it has been warmed up. This is a sign of warm up regulator fault.
1. Out of calibration to the RICH side (too far open) must be reset by trained personnel only.
2. Out of calibration to the worn engine (higher counter pressure against the metering pin). This causes the cold engine to run very lean. A new warm up regulator will only do very little as the sensor plate still has not enough air flow to be lifted high enough.
3. Warm up regulator restricted with dirt or blocked or faulty in the electrical circuit. Remove the hose from the regulator towards the fuel tank and check for fuel flow. Use test light or ohm meter for continuity check in the heater wiring circuit or plug.
**All information are partly NOW in the Members Data Pool as refresher! **
Shortcut back K-Jetronic site plan.
<a href="http://www.users.bigpond.com/INTERJECT/KJETRON.HTM" target="_blank">http://www.users.bigpond.com/INTERJECT/KJETRON.HTM</a>
excerpt:
THE ENGINE WILL RUN SMOOTHLY, after it has been warmed up. This is a sign of warm up regulator fault.
1. Out of calibration to the RICH side (too far open) must be reset by trained personnel only.
2. Out of calibration to the worn engine (higher counter pressure against the metering pin). This causes the cold engine to run very lean. A new warm up regulator will only do very little as the sensor plate still has not enough air flow to be lifted high enough.
3. Warm up regulator restricted with dirt or blocked or faulty in the electrical circuit. Remove the hose from the regulator towards the fuel tank and check for fuel flow. Use test light or ohm meter for continuity check in the heater wiring circuit or plug.
**All information are partly NOW in the Members Data Pool as refresher! **
Shortcut back K-Jetronic site plan.
