dom1102

Can anyone help - My very well maintained 88 s4 has developed a starting issue, it generally only occurs when the car is warm (eg always starts from cold or when the car has sat for an hour or so). When I turn the key nothing happens. The dash lights all come on but the starter motor does nothing. if I then hold the key round in the start position for 10 - 30 seconds (dash lights remain on) the starter usually comes to life. Ocasionally if it still wont start, the only thing that seems to help bring it to life is to first turn the ignition off then lock and unlock the drivers door using the manual **** on the inside of the door then turn the key again then it will usually fire right up. Have tried 2 new batteries (courtesy of the 2 garages who have now tried to "fix" it), changed the big round plug on the back of the ignition switch, by-passed the gear selector (autobox) saftey cut out and had the starter motor and solonoid bench tested (showed no problems). The car is fitted with a fairly old full-closure clifford alarm system which I rarley use (I dont use it all the time so I lock it with the key to save the battery going flat) and the original fit porsche imobalizer on the underside of the steering column with the small key chain plug-in "beep beep" thingy. Im beginning to think I should just bite the bullet and get an auto electrician to just rip out the alarm and imobalizer but judging by the way the alarm is wired in this will be an expensive and potentially problematic gamble. Please help, the car is pretty much useless at the moment because I dont trust it.

Mrmerlin

swap out the starter relay, this has stopped many 928s from running IIRC it is the same as the horn relay
Also check the hot post connections and the 14 pin connector above the hot post for corrosion.
Usually the starter relay fails due to excessive cranking this over heats the relay and then it melts internally, you may want to open the relay and look for melted parts around the board portion
Get a fuse relay chart here www.928gt.com

Also remove the battery connections and clean all of them and also the ground wire for the chassis to the bottom of the engine and check the starter wires for solid connections

Alan

Well based on what you say - I think you have to remove all the alarms for the best shot at making it reliable. Based on what has been done removing the alarms should not be too hard. BTW what was done here was probably the right steps in debugging such an intermittent thing. The Alarms are next in line...

Alan