Starting problem

S4 1992 was running great for a few weeks, after took off hard top, so thought that must have been draining the electrics. Today started and ran for first time in 2 weeks. started first time. , drove it 10 miles and parked .After 15 minutes went to go home and all dash lights showed but wouldnt start. Not even a click from the starter. Put on ump leads went first time and will start just now if try. Could it be a faulty starter?

seems to be something to do with the immobiliser and the alarm which i have receipts from 1999 for the fitting.
was there a factory immobiliser on some 92 spiders?

Check your battery connections are clean and tight. Undo the starter motor connections and clean then off with contact cleaner and emery paper. Make sure that the are tight and put some silcon grease on to protect it. Also unplug the thin black lead to the starter and clean it and the male spade connector on the starter motor. Make sure it is on tight. If this does not work let me know. Ps undoing these connections is a real pain and you will need a socket set with extension bars to get at them.

Could be your starters jammed if its not turning over...

will try suggestions, thanks.
As for the starter jamming , will need to wait to tap with hammer next time see if that works, electric readings all seem fine, have been through it thoroughly then thought found problem was hardtop electric connection drawing power took it off and went for every time for a month till other day.

Update
went fine for a few days ,
started every time first time for a few days, then this morning, dash lights as normal on ignition then a click and it wouldnt start. Rocked it in 4th and tapped starter with hammer still wouldnt start.
Tried all the buttons on fob in case an immobiliser problem but no.
After a leaving for a while decided to jump it, if a starter problem or an immobiliser prob jumping wouldnt help.
Started first time and runs fine again. But will still need to find problem before running everyday.
A wire must be breaking down somewhere that once gets a boost of power works for a while. If the starter black earth wire wasnt connecting right why should a jump help it for a while?

Just get the battery checked properly - see what voltage it's holding and what it cranks at. Then follow from there - leads earths etc to the starter.

Thanks getting it checked today .
Guy feels more alternator than starter at the moment everything seemed to check out last time so not really too hopeful to find problem when its in its starting mood.

checked but still feel no further on
slowly ruling out causes.
battery was flat. No drain of power showing. replaced it and it started first time. All readings over the battery perfect pointing to battery not taking charge sometimes. Starter seems fine and so does alternator from all the readings.
turning my thoughts to an ignition or coil problem now, but will run on new battery and see what happens if this keeps its charge.
does the coil have a resistor which could cause intermittent breakdown, I seem to remember problems like this when a 9 volt coil used and not a 12 volt. Or could it be a problem in the ignition barrel
remember the slightest jump and it starts.
Maybe a combination of coincidences.

Have a read of this link.....http://www.alfabb.com/bb/forums/show...=starter+motor

Checked that piece quite interesting but i think not relevant as mine was doing this intermittently hot and cold.
Anyway have progressed inthis problem. First I thought is was the immobiliser so we disconnected it and everything ran perfect thro august and september. Didnt use it for a few weeks and went to restart it the other day and found it completely drained .Jumped it and took it for a run to boost the battrery but after 2 days was dead again, maybe never charged it enough. Let an electrics guy look at it again found the battery draining from the radio and clock, personally dont thimnk they are the problem so am trickle cgharging the battery just now and think that I may have to use it more or disconnect when not using. Anybody else had a radio draining the battery?

Sounds like it is a problem with the battery not having enough power to operate the starter. The obvious causes are:

1) Duff battery
2) Charging problem
3) Battery being drained, boot light, alarm etc.

I suspect the new battery will have cured your problem. I have a similar problem on another car which only started after an alarm was fitted. After the car has been left for a few days and although the dash lights come on it will not start. Jump it and it starts on the button.

Best of luck.

Check the under-dash footwell lights are going off when you close the door. Dead easy to knock them into the on position and drain the battery.
If it’s not that put a meter on the battery with the ignition off and see what the current drain is. Then start pulling the fuses one by one to identify the source of the drain.
When the car does not start you say there is no click. What does the dash volt meter do?

A common problem with the S4 is voltage drop across the charging circuit. The last S4 I worked on had 13.7v at the alternator but only 12.4 at the battery! This car had the same symptoms; flat battery after a few days but would start right up with a jump. The fix was to clean the connections at the alternator B+ terminal, junction box on left inner wing, starter and battery. Voltage at the battery went up to that of the alternator. No problems now for a couple of months.

Thanks will give that a try . working on it this week anyway, time to fit hardtop i think