Questions and Answers

Volvo 740 Hard To Start When Warm Q. Hi, I have a 1987 Volvo 740 2.3 liter SOHC Turbo with an automatic transmission and 230,000 kilometers. The car starts and runs like new when warm but when engine is cold the car turns over but won't start. There are two tricks to starting it. One is to raise the voltage from 12V to 14V or more, boosting or battery charger. The other is to turn the key in quick pulses.

In this second case the car actually starts when you let go of the key. If you hold the key in the start position it will just wind over and there will be no gas smell at the exhaust. The spark and fuel delivery have been checked at a repair place.

The battery is new, the distributor cap, rotor and spark plug wires are new. The ground wires have all been cleaned and checked. The fuel pump relay and fuel pressure valve have been replaced. All connectors to AFM, throttle position, idle valve etc have been cleaned.

One odd thing is when the car was cold but the spark voltage tester was hooked up, the car started well. Help please.

A. There's a couple of checks I would do in this case. The first a check of the ignition switch. Worn contacts would cause the symptoms you describe.

The other is a resistance test of the ignition coil. A high resistance coil would also cause this to happen. The fact it started with a spark tester hooked up would seem to support the case for a bad coil.

1. Check ignition coil primary winding by connecting an ohmmeter between ignition coil terminals #1 (red-white wire connector) and #15 (blue wire connector).

2. If resistance is:
   • too low, replace ignition coil and retest.
   • too high, check resistance between coil terminals 1 and 15. Reading still to high, replace coil and retest. Reading correct, repair fault in wiring or connectors.

3. Check ignition coil secondary winding by connecting an ohmmeter between coil terminals 1 and high-voltage outlet.

Reading: 6.5 - 9.0 K ohms

4. If not, replace ignition coil and retest.