New toy WILL play :-D

[grinder]

hiya chaps

been on the phone to allan for 55 mins so not really worked on the car

thoughts and ideas at the mo

1 - take the ecu out of the coupe and try it in the car - this is a quick and easy test and will prove weather or not the ecu is at fault
2 - the main relay ( up by the coil ) this tests OK when we checked it - apply power and it clicks - remove power and it clicks off
3 - when all the clicking starts - this does NOT click - it clicks on and then off ( with the key ) - so we can assume this is working correctly
4 - what we dont know - is it putting 12v ?
5 - there is a pin on the ecu that should get 12v at cranking - this is only getting 9.7 - BUT the clicking starts before the cranking - so cant see this being an issue ( YET )
6 - as rxmotors said - prob a bad earth - tie in the with lights not moving
7 - prob is - where to find it - is it a bad body earth or a break in the loom somewhere
8 - starter is working fine - so looks like the battery side of it it OK
9 - i have checked the engine for an earth by putting a jump lead from negative terminal to lots of places on the engine - still clicking
10 - nothing plugged into any check connectors - checked this tonight
11 - how do you check a wire for a good earth ?? ( i assume you need to find the start and end of it - thats prob not that simple )
12 - does anyone know the sequence that things are powered up ?? ( i know the main relay is OK - does this mean the problem lies further down the chain )
13 - it has been suggested dont even try and start the car with all the clicking ( so just getting stuff for when it is ready to fire )
14 - ECU earth has been checked - belled it thru back to the battery - and its fine

thats the state of play at this moment intime - i must admit if i knew it was gonna be this bad - i wouldnt have touched this car with a barge pole !!

Stu

[Mobilemick]

11 - how do you check a wire for a good earth ?? ( i assume you need to find the start and end of it - thats prob not that simple )

Get a bulb, put one wire onto pos of battery, and the other onto the earth wire you are checking,  it should light up if the earth is OK

Mick

[grinder]

oohhh i like it Mick - i have just the thing in the garage

something else to check before i rip the entire loom out

cheers

[Prof]

Just had a brain fart stu !
 
You can check to see how much the injectors are firing using a wee bulb as well.  Since the ECU outputs for the injectors are basically just being grounded when the injector is being told to fire, you can check if these are responsible for some of the clicking, by carefully removing the connectors, and jumpering your bulb across the plug instead.
 
If the light flashes strongly, then the injector duty cycle is high.
 
For Cranking, the Secondaries should be off, and the primaries should be getting 50-70% duty cycle to get the engine started (rich), which settles down to a much lower duty cycle when the engine is running.
 
Until you crank, neither primary or secondary injectors should be firing.

[grinder]

can i meter this at the ECU ??

and mick - does the battery need to be connected correctly to test with a bulb ?

[Prof]

Should be able to - basically the injectors are quite low impedance, so when the transistor that fires the injector is off, the voltage seen at the injector drive pins will be 12V, when the injector fires, the voltage drops to nearly 0V.

The reason for using a bulb, is that you can get a much better idea of duty cycle -  i.e. how much on versus off time, meters are not very good at providing that kind of display, but a bulb will vary in brightness with the duty cycle.

[Prof]

Just a side piccy of your ECU Stu - shows the depth of water that this baby was sat in at one point !

Clearly a lot of the lower analog board was submerged !:guinness

BTW Stu - I had to replace one diode on the board - the leg had been eaten away - it was the +12v feed to 1a on the ECU - which makes sense, as this would always be connected, even if the ingition was off.  The leg was probably eaten away by electrolysis, as there was no sign of it anywhere.  Luckily most of the board and components survived the deep wash cycle !

[grinder]

never noticed that when i took it out

thats a lot of water LOL

Stu

[FD3SNuttah]

injectors work on negative pulse - u wont be able to see it on a standard mulitimeter.

[Prof]

injectors work on negative pulse - u wont be able to see it on a standard mulitimeter.

Will too - if you are measuring the sigal coming out of the ECU, and have not unplugged the wire harness, then the injector output will be \'floating\' up to 12V through the low resistance of the injector itself, and will be brought down to ground when the injector is fired.

If you try and measure it with the plug out, then you are correct - you wont see any voltage to measure.

[grinder]

the problem with that is trying to get a meter in to the back of the plug - not that easy based on ( 1) its a tight fit (2) the angle of the ecu

more things to check ...

[Grizzly]

I spoke to our Auto Electrican at work today and he seemed to thing Fuse Box\'s often cause theses sorts of Problems but its more likly to have Poor power or Lack of power all together (dry joints etc)

TBH i don\'t know about this i don\'t recall alot of engine Stuff in the Fuse box, but he said there\'s see\'s loads of faults like this on older cars so its just some thing else to look at. Plus he knows alot more than me about Wiring faults in cars..

[Grizzly]

Have you seen this?
 http://www.mazdarotaryclub.com/forums/showthread.php?t=30821

Watch the Vid, That would be a Mint Deflood trick. Just do the air line Bit at the end and it will dry it all out

[shaunwil]

What thread is the sparkpugs I can supply the compresser if you want to have a try. Will chat about it tommorrow !

Shaun

[Mobilemick]

I got a set of Noid lights stu, which will tell you if injector is getting power.