Won't turn over or start

[Jonah]

First post on here to try and get some advice to get my pride on joy back on the road. I have a Mk2 2001 1.8 which has been a reliable starter until the past 2 months.

First signs of a problem was while I was away and the wife tried to start the car but failed thanks to a flat battery. Kindly neighbour stepped in and charged the battery. Initially all the electrics would come on but engine would not turn over. They tried jump leads from another battery but same result. When I returned I put the battery on a 24 hour charge and the car turned over and started but I noticed when I took it for a run that it was struggling to idle.

A week or so after after standing again same problem, flat battery. Another good charge but this time it would turn over but refused point blank to fire up. Soaked everything electrical in WD40, tried jumping from another car, recharged the battery same result - except once or twice before putting the battery back on the charge the engine wouldn't turn over so I assumed the charge was too low.

On the last occasion after a fresh charge and the car would turn over but wouldn't start I thought time to try the RAC home start. When the guy in the orange van turned up the car wouldn't even turn over. In fairness he spent a lot of time checking through the whole electrical system and on the RAC online help tool got as far as water in the passenger footwell - lifted the carpets and yep, soaking wet and signs of corrosion up to the ECU bracket. RAC chap called it a day and left me to it.

After losing most of the skin on my knuckles the ECU has been removed and dried out (even though there was no sign of water ingress of corrosion), connectors cleaned, ALL fuses checked, and reassembled. Battery charged (again!), ignition turned on - nothing. All electrics seem good (fans, power windows working correctly) so starting to lose hope it will feel the wind in its hair ever again. Code reader throws up a generic P3302 code.

Can someone help? The manual says this car has an immobiliser but if it does I've noticed the light doesn't come on at all. Looking through the web I don't think I'm the only one who has experienced this issue but the advice and solutions seem wide and varied.

What I would appreciate is a logical fault finding sequence rather than trying to attack everything electrical at once.

Thanks!

[Jonah]

A bit of progress today to add to the info in case anyone feels the urge to help me tackle this one!

Battery fully charged (again!) over Christmas and after fitting today the engine turned over a treat, but still refused to start. The fuel pump appears to be running (can hear it still spinning for a second or two after the ignition is turned off) but no smell of any fuel in the engine bay or exhaust despite turning several times with the throttle fully depressed. Also, the ABS warning light comes on when the ignition is turned on as well as the check engine light (albeit a bit faint), as expected both go off when the engine is turned. Neither came on at the last attempt to get the beast running again so I suppose that is progress.

In a throwback to the '80s, I finally tried injecting Easy Start into the air intake but nothing, so appears to be no spark or fuel.

Open to ideas as to what to try next.

[Mazda Mender]

Ok just a couple of questions...

What type of battery? OE gel or aftermarket wet cell? and how is it being charged? trickle charged at low amps or a normal battery charger? OE, 24 hr charge on a OE gel battery is not good enough and it 100% needs to be done on a low amp trickle charge as you need to " recondition" a gel battery not charge it.
When it was " jumped started" how and where wast it done? there is a wrong and right way to do it on these roadsters, to much volts can fry things and cause all kinds of faults and issues...soaking everything electrical with WD40.... really ????what did you soak? and how bad? that would not of been a good move...ever..

On line help tool???? whats that then?, you mean he did a search of common issues with these roadsters on line as it is also on here, now it does sound like you have found the fault??? the ECU's do not like water or damp and can throw all kinds of faults and issues on the ECU's circuit board, drying it out is very hit and miss whether it will be ok or not. "IF" it is the ECU then there is a fix that you can do yourself (which is on here) without paying a garage bill, but we will get into that later as a last resort.

Now is she only throwing out P3302 fault code? is that a code you have found with a OBDII reader or the good old RAC man? if you have a reader just run a test again and lets see what she throws out again.

There is a lot of sensors that can fail in the engine bay that could be giving you the issues, so we are into a fault finding exercise now.
Where are you in the world.
M-m

[Jonah]

Thanks for the response, answers below:

1. Battery: replacement wet cell and it was on a low amp charge. I am always wary of a slightly undercharged (or old) battery having spent several hours trying to cure an old Ford Focus starter issue some years ago. A couple of the local garages couldn't find the fault ("it's your starter motor mate") but searching round the web I discovered there is a voltage which, if the circuit dips below on starting, the ECU effectively appeared to shut everything down. A long story cut short but a new battery and the car is still being driven by one of my sons and has been reliable ever since. This is in the back of my mind on the Mazda as whenever I give the battery a long charge the car turns over (but still won't fire).

2. Jump starting: I wasn't here when my neighbour tried it but under interrogation he finally cracked and confessed it was from a spare battery he has in his garage. He is a good engineer so would have made sure they were connected in parallel and not series. I tried it from the wife's Golf once when it wouldn't turn over and although it span it still wouldn't fire.

3. RAC help tool: yep, this was news to me as well. He kept disappearing to his van and on the last visit took me with him to show me what he was referring to on his tablet. I assumed it was online but either way it was a RAC specific help tool that helped him step through a fault finding sequence for that particular year of MX5. He did a through check of the starter and ignition circuits but he drew stumps when it advised the ECU and he saw the two rivets of death that needed to be hacked away.

4. P3302 code: I've got a OBDII reader which I use on my other hobby - a 2006 Volvo XC90. For the Volvo it has proved its worth in pulling up the right codes (which is why I bought that particular model). However, for other makes I have found it only throws out generic codes. The P3302 code has been consistent after erasing the codes and then it pops up again. The RAC chap didn't get as far as plugging his in (maybe Home Start doesn't cover a free check of the codes?!)

5. Located in Weymouth, Dorset - where the current weather is clear skies, no wind, perfect for driving in an open topped sports car.....oh no, just remembered

Some additional information which might help is I purchased the car earlier this summer from a friend who had owned it since 2007. He gave me all of the receipts (servicing etc.) and from what I can glean the plugs and fuel filter might not have been changed since 2007, coils and leads are possibly all original.

[Mazda Mender]

I would check with your buddy...if that is the case then lets try them first as they are cheap enough to swap out
...but it is looking like it is an electric fault.. possibly from a surge ....but as i said it could be a sensor at fault? I'll check the fault code...
M-m

[Jonah]

Some developments....

Fuel filter OK but no spark being generated. Checked the gap on the crank angle sensor and within spec (is there a way of checking the crank and camshaft sensors functionality beyond general condition and the gap on the former?). Checked electrical connections (again!) and also engine earth (as it was an easy one and seemed to pop up in one or two forums!).

Fresh battery charge and turned it over to see if any codes popped up - hey presto, P1624 Anti-theft system. So has it been an immobiliser issue all along connected to the first time the battery went flat? I'm not surprised the code didn't show up previously as the reader I have does sometimes take a few goes to get the codes up (from experience of regular use on an XC90!).

So before I start trawling through all the forums looking for a P1624 fix does anyone have any suggestions or how the system can be "reset"?