1979-1993 & 94 Conv [Subscribe to Daily Digest] |
Cold starting problems can come from many causes. Depending on the temperatures involved, here are some of the known sources.
Fuel related:
1) Cold starting injector is dirty or plugged.
2) Thermo switch for the cold starting circuit is defective.
3) Fuel pressure diaphragm regulator is set too low. This usually will allow starting but stumbling and poor engine performance until the engine has warmed up.
4) Leaking injectors cause fuel pressure to drop while car is not running and make for long cranking before pressure is adequate for engine starting fuel delivery. Poor performing injectors will also cause many engine performance faults and losses.
5) Worn fuel pump causing intermittent operation.
6) Worn fuel distributor causing fuel pressure leakage making the same effects as in (4) above.
7) Plugged fuel filters, making for insufficient fuel flow.
8) Fuel pump relay contact points burned and producing poor or intermittent electrical contact. Corroded wiring and terminal connections can produce the same problems.
All of the above produce the same effect of low or no fuel delivery.
**One intermittent problem I have not been able to find the source of is an intermittent cold and humid starting problem. This is on a 1988 SPG Turbo 16 valve. It will not start!. Upon checking for voltage at the fuel pump it is zero while this intermittent condition exists. Letting the car warm up in the sun automatically eliminates the problem and the car starts and operates as it should. Over time it has been determined that this is not so much a temperature (as in cold temp) so much as it is a humidity related problem.
Has anyone had a similar humidity or cold starting problem??**
Ignition (spark delivery) related:
9) Faulty Crank Sensor (ignition trigger) causing absent ignition spark.
10) Defective and intermittent ignition coil.
11) Leaking high tension wiring, including wires, boots and plugs. Causing the spark to leak before being delivered to the plug gap.
12) ECU defect. Rare but exists and is an expensive replacement.
13) Battery and terminal and wiring connections are corroded causing excessive resistance and delivering insufficient voltage to the ECU and relays for proper operation.
14) Defective battery (insufficient voltage/amperage output) or a defective charging condition will cause the same thing. These both make for potential computer and sensor faults.
Please let me know if you find any other answers. Hope this helps.
Best,
Tom
posted by 209.142.1...
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