In my case I believe it's the key and tumbler portion that has worn/failed, the one that requires a somewhat heroic effort to replace, consisting of removing a bunch of headless anti-theft screws to nearly disassemble the steering column. Started, gave up after after a few minutes, intuition?
So my story went like this since last post: after I installed the backend of the ignition switch, the part that actually has the electrical contacts and wiring as is turned by the key and tumbler, my car still wouldn't start, would turn over, finally, but would only weakly cough just once or twice a day but never on back to back attempts, I thought that clearly this must be an issue with fuel. So I did the cold start valve in a Gatorade bottle test. I had been using the sniff test at the tailpipe and was sure gas was present. Watching the moderate dribble I thought to myself: that really what happens to some men as they age? So next on to the fuel pump to prod and poke. Now realize this is all happening a town over in an open bay of one of my friends commercial greenhouses, the return of a favor for brazing a waterline inside a wall of his house after he botched the installation of a shower handle, one of those three way deals where all the pipes meet, something akin to a simple version of the infamous Jules Verne device. So a few weeks after we got the fire out and the water back on, my ride decides it doesn't want to leave Starbucks. What are friends for? Now back to that fuel pump, get the back end up, tire off, thankfully the greenhouse had cement walkways to lay on, thinking I need to check the electrics. You know those lightbulb comic cartoon moments? Had me one ó them. Socket wrench in hand for the fuel pump terminals, I have some sort of déjà vu moment, flip the wrench around and rap the pump a couple times, not hard, gently, but firmly. Roll out from under and with catch bottle in hand, reach in and turn key to on and behold a veritable firehose of fuel. I don't think those bull semen collectors get as excited as I was to watch that receptacle fill up. Anyway it started and ran great for a week maybe, then started the intermittent key jiggle start thing again so I spliced a toggle switch into the black start relay wire from the switch, punched a hole in the "extra" knob next to the light switch and we've been happy ever after. Except the times I hit the toggle before I turn the key on then wonder "what now" as it whirrs with no start. Or the day I left it in D (...is for dummies) popped in and out the store and it's dead, switch on, toggle on, nothing. Still a dent in my forehead matching the upper part of the steering wheel when I realized what I'd done.
Occassional Starting Problem - Relay?
My car came like this - it has a heavy-duty 'engine start' button in the dash in the blank space. The PO explained the exact same scenario to me, and his mechanic just bypassed it with the button.
Due to this, yes the button will crank without the key in, but won't start. I don't mind it but it makes giving the car to anyone else a pain as the button isn't labelled, plus you can hit the button while the engine is running (not good).
So my plan was to a. buy a cheap "engine start" labelled button off eBay. But how to stop accidental cranking?
My idea: put a relay between the button and the starter, powered by the oil pressure sensor - when the oil light is on, the relay has power, closes the contacts and enables the start button to work. Engine off, key out - no oil light - no cranking. Engine on, oil pressure, no oil light - no cranking. Engine off, key in - oil light - can crank.
Due to this, yes the button will crank without the key in, but won't start. I don't mind it but it makes giving the car to anyone else a pain as the button isn't labelled, plus you can hit the button while the engine is running (not good).
So my plan was to a. buy a cheap "engine start" labelled button off eBay. But how to stop accidental cranking?
My idea: put a relay between the button and the starter, powered by the oil pressure sensor - when the oil light is on, the relay has power, closes the contacts and enables the start button to work. Engine off, key out - no oil light - no cranking. Engine on, oil pressure, no oil light - no cranking. Engine off, key in - oil light - can crank.
1979 528i - Sold
Interesting proposal, it took a couple of reads to follow it. Yes and no, I think it would work if you source 12V to the relay separately, but not if you tried to just insert the relay in series. I'm thinking a diode might be needed too, but I can't quite say why, maybe not. But why not just replace the ignition switch? It's not that hard or expensive.Lock wrote:My car came like this - it has a heavy-duty 'engine start' button in the dash in the blank space. The PO explained the exact same scenario to me, and his mechanic just bypassed it with the button.
Due to this, yes the button will crank without the key in, but won't start. I don't mind it but it makes giving the car to anyone else a pain as the button isn't labelled, plus you can hit the button while the engine is running (not good).
So my plan was to a. buy a cheap "engine start" labelled button off eBay. But how to stop accidental cranking?
My idea: put a relay between the button and the starter, powered by the oil pressure sensor - when the oil light is on, the relay has power, closes the contacts and enables the start button to work. Engine off, key out - no oil light - no cranking. Engine on, oil pressure, no oil light - no cranking. Engine off, key in - oil light - can crank.
Mike W.
02 525ita. Wife's, aka grocery getter
02 530i. New to the fleet, 3 pedals.
03 QX4, AKA the Datsun. Finally got the 4WD vacationmoble to stop smoking.
07 Xterra. Still on the DL, a purchase from hell.
02 525ita. Wife's, aka grocery getter
02 530i. New to the fleet, 3 pedals.
03 QX4, AKA the Datsun. Finally got the 4WD vacationmoble to stop smoking.
07 Xterra. Still on the DL, a purchase from hell.
Yea sorry my thoughts were all over the place because I was originally thinking the alternator/charge lamp which is a +ve signal, but running in series or parallel with that might damage the regulator or cause unpredictable behavior.Mike W. wrote:
Interesting proposal, it took a couple of reads to follow it. Yes and no, I think it would work if you source 12V to the relay separately, but not if you tried to just insert the relay in series. I'm thinking a diode might be needed too, but I can't quite say why, maybe not. But why not just replace the ignition switch? It's not that hard or expensive.
But our oil pressure units are on/off only (not variable), so getting a +ve from the 'on' ignition circuit, to relay coil, to -ve oil signal line would be better. The coil would close the relay contacts only when you'd want to start the car. And totally agreed, I would put diodes on there too to stop any accidental power back flow. When I do this I will take pictures and can sketch up a circuit diagram if anyone wants, as broken ignition switches seem to be common.
Only reason I haven't replaced the ignition switch is this is just one of many tiny issues to fix, mine is no show car by any means (I'd go with ugly but practical), and this solution seemed effective. Plus I have a few other vehicles demanding my time and money so I alternate.
1979 528i - Sold