Non-start when hot

I have a 1993 Toyota Soarer 4.0 V8 with engine code IUZFE. The engine starts and runs OK but, once switched off, it will not restart immediately. I have checked and there is no spark. However, if I leave it for some time, it will then start. I have not been able to retrieve any fault codes. G Peachey The Soarer was built for the Japanese market and the IUZ-FE engine can also be found in the Lexus LS 400. The ignition system is Denso PK 20 R and uses crankshaft and camshaft sensors to control the ignition timing. As the Soarer was never available in the UK, I have only limited details as to which diagnostic link is fitted.

You may have a round or oblong connector in the vehicle. Both connectors will have a terminal marked ‘E1’ and ‘TE1’. By bridging these terminals, the malfunction indicator lamp should flash out any trouble codes. If there are no codes in the system, then the light will flash steadily twice per second. If trouble codes are present they will be flashed out as follows: the first digit will be flashed at ½-second intervals, followed by a 1½-second pause; the second digit will then be flashed out. If another code is present, this will be flashed out after a 4½-second pause.

As the failure to start is dependent on temperature, I suspect that either one of the camshaft sensors or the crankshaft sensor is at fault, failing when hot. It may be possible to test the sensors using an ohmmeter, but this would need them to be at the correct temperature for the failure to occur. The code for the camshaft sensor is ‘12’ or ‘13’ and the code for the crankshaft sensor is ‘43’.