Have just acquired a Senator 2.5 1989 Automatic, 80,000 miles on the clock. The car looks in great condition and runs well after a cold start-up, but when the engine is hot and switched off it often refuses to start again till it has cooled down! Any help or suggestions will be most appreciated. Thanks in advance, Dave.
Is your car an automatic? If so, it could be the gearbox inhibitor switch which is causing the problem. This switch prevents the car from being started if the selector lever is positioned anywhere other than P or N. The switch is located on the outside of the transmission and gets very hot due to it being close to the exhaust.
Fortunately, there is a connector in the engine bay. Looking from the front of the car it is right at the back against the bulkhead and to the right-hand side. Look for a long, black cable/wire coming up from under the car to a 2 pin connector (there's a 3 pin one nearby - not sure what this is)
Open the connector and use some solid core copper wire bent in a U-shape. Bare the ends and push into the female connectors. This shorts out the inhibitor switch and may solve the problem - it did with my 3ltr Carlton auto. If it does solve the hot starting problem you will find that the car can be started whilst the selector is in any position and your cruise control will not work (if it's doing so at present).
I found this to be no big deal but didn't. I discovered that my battery was on its last legs. After replacing the battery I was able to reconnect the inhibitor switch and have had no problems with it since. I'm assuming that there wasn't sufficient current/amperage or whatever to deactivate the inhibitor switch when it was hot.
It took me a long time,lots of patience and many times of waiting for the engine to cool before I discovered this. I hope it helps you.
By the way. There is an excellent forum where there is an amazing amount of know-how for Senator owners. Have a look at:-
Assuming it actually turns over on the starter when hot.... sounds like you have a faulty cam phase sensor in the dissy, which is the primary ignition input on this engine- dont think the 2.5 uses a crank angle sensor.
Check for a square wave form 0-5-0-5v etc signal from pin 2 during cranking to be sure..
Tim..
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