GTV6 Dreaded Start then Stall

[Al Campbell]

Shane,

Careful with the colours of the wires. I've found some around the front of the engine bay that have faded, particularly the stripes. It's not until I traced the wire back along the bundle (hey that pink wire changes to grey!) that I worked out what was going on. Although probably not likely near the double relay as I suspect heat is the issue.

W.R.T. the double relay circuit - have you checked out the American ALFA site? There's an electrical section and there is a fair chance someone has already done the circuit.

Had a thought, page 20 of the L-Jetronic Manual from "Craig's Place":

[shane wescott]

Thanks for the info Al.

Had a frustrating night tonight where I thought it would be a reconnect and worky but I have gone backwards.

Now I am back to no fuel pump when you trigger the AFM switch..

On one connector there is a violet wire, looking at the diag I am assuming this should have 12volts, it comes from the ignition switch and is joined to the +ve side of a diode.  There is no volts there, and also no volts on the AFM switch.

I think by looking at the diags that the volts for the AFM switch comes from the ECU, but if the ECU gets crap input it is likely to have a crap output.

I will do more reading and tracing etc.

As I've always said to newbees in IT who I've worked with " I hope you have lots of problems because thats how you learn heaps. If everything goes the way it should you learn nothing".

I am enjoying learning about the Fuel injection on the Beast but I think I've leanred enough - come on Alfa Fairy - throw me a frickin bone here :-)

Update some time.

[dehne]

have you tried another relay at all, im sure someone is close to you and could pop over for a quick try,

[Sheldon McIntosh]

Good point.  I've got one I won't be using for at least 6 months, come and grab it from Brunswick if you want Shane.

[shane wescott]

Hi Guys

It is defo not a stuffed relay. I have a quick and simple method for testing these and mine is doing all the right things (thinking about building a little test rig for them).

Tail chasing is something I do very well so trying to avoid it.

One quick dumb question. Docos referr to the ECU as living behind a panel in the passenger side. Is the ECU the metal cased lump living on the pass side under the bonnet just near the coil, or is that something else.

Thanks

[AikenDrum105]

Hi Shane,

the ECU is mounted under a panel next to the accel pedal inside the car, looks like this:



the little one near the coil is the spark ECU (I think)

Good luck !  I had a GTV6 for a while - and actually have some respect for the old L-Jet...  but a 'will not start when hot' and 'always rich on the overrun' finally beat me, and I MegaSquirted it

But that V6 howl in the domain tunnel - I still dream of it....

[AikenDrum105]

Come to think of it - mine had a switch when I bought it under the dash to bypass the tachimetric part of the dual-relay and power the fuel pump.  I pulled the relay down and cleaned the points and got it going again - but the switch was there, just in case

[aggie57]

Shane - do you have access to the factory engine manual?  I have one so if you want I can copy the relevant pages and email them to you.  PM me if interested.

Alister

[shane wescott]

Thanks Aggie but  do have all the manuals (bought a Car Disk when I got the car)

Right so there really IS a panel and ecu hidden behind it, i will have to open the panel and show it a bit of love.

Speaking of showing love I have put a good photo of my GTV6 as my wallpaper on my phone and relagated the Ducati photos to another place - hopefully this might send out some good vibes and a howling I will be soon.

On a serious note, there is a connector under the steering column which has a thick dark wire and a violet wire which runs down to the Dual relay. According to the wiring diagram this connects to the "roof lamp timer" and the ignition switch.

If anyone could check if there is 12volts on this violet when the igniotn is on that would be great. My belief is this is needed to signla the ECU and then the ECu will provide volts to the AFM switch so the fuel pump will run .

Catch ya

Shane

[AikenDrum105]

hopefully this might send out some good vibes and a howling I will be soon.

If that doesn't work - try the opposite tack - leave the Angle grinder on the front seat of the GTV6 overnight....

[shane wescott]

Right so that would mean that if I stick a mmeter on it and turn the key to start I should see 12V.

Excellent Choderboy, that is exactly what I needed to know.

Pulled off the plenum today, just to make sure all the fuel lines to the injectros were proper tight, and metered out the wiring to make sure I have the injector wires on the right connectors on the dual relay - all good.

Trap for non observent people like me - whe  you take off the throttle cable to get the plenum off, the little arm rocks back and sits down in the area where the injectors are.

If you aren't observant (that would be me) and you just pop the plenum back on and carefully tighten everything up - you notice when you get to put the throttle cable on that the little arm is stick and the plenum needs to come off again.

No worries, I enjoy doing things a second time just to make sure I know how they are done :-)

I think I am getting closer. Even pulled out the computer today, smelt funny so had a look and nothing appears to be burnt out so that is a good sign.

Again thank for the help guys, and the angle grinder is staying where it is at the moment - talk to me next week if the Beast is still playing up :-)

[shane wescott]

Success - well sort of.

This morning I put the refitted the plenum so I could get the trottle cable connected.

Then I put a MM on the violet wire which should fire the relay for the fuel pump when the ignition is in start mode - all cool volts there while cranking.

No fuel pump though.

Given that there is two things needed for a relay to fire 12v and an earth i thought i would chec the earth.

So I disconnected pin 85 off the dual relay and hooked the pin directly to earth.

Cracked the key and bingo - the Beast lives.

So my theory here is that in my stupidity when chekcing the wiring on the dual relay I did swap the wires on 85 and 86 because I was convinced I had them on arse about. Looking at the diag that would put 12v onto one pin of the ECU which normally puts out an earth - so I suspect I now have an issue inside the ecu.

I am trying to locate a circuit diag of the ecu so If anyone knows where one lives please let me know. I am 'hoping" it is a simple output which basically switches an earth on if the ignition is turned on and isnt hooked directly to a specialised chip.

So I believe my original fault was the blown coil in the dual relay (fixed by a $7 relay and a bit of solder), and the rest of my isses have been caused by me messing up which wire goes on which connector on the dual relay.

I agree Choderboy that mucking around with additional things will generally make a small job snowball into a much larger job, but that's been my life with cars and bikes. The positive of that is you generally fix a few more things and there are less future issues )in theory) and you learn a lot :-)

Next project is fix the speedo on the Ducati - sounds simple but I have to remove the front forks, swap them over, reposition and remount the brake calipers, and refit the front tyre just so I can avoid speeding fines.

All thanks to the previous owner who for some unknown reason refitted everything arse about which caused the speedo to work in reverse, and everythime you go for a ride the engine gets younger :-)

Catch ya

Shane

[shane wescott]

Quick Update.

Nothing to lose so pulled out the ECU to check it out. Traced out pin 28, which is the one I stuffed up, and found a burnt out PCB track :-) This explains the "brown" smell from the insode of the ECU.

Had to desolder a capacitor to get the track, rebuilt it, put the ECU back in and WHOOO HOOO  it is now fixed and up and running :-)

Had a dicky spark plug which was dirty so pulled that cleaned it and she is now puring like a kitten.

Problem is I've had a gutful of the GTV6 over the last week so it can wait for a decent run. Might even take the Ducati out for little spin later just to piss it off.

But then again, there's probably nothing more dangerous than a GTV6 scorned.

I hope this will help someone in the future, I've certainly learnt heaps about the FI system from you guys, so thanks for the help and I will see you on a club run soon.

CAtch ya

Shane

[Neil Choi]

Shane

It has been a pleasure reading your trials and tribulation through it all and all the help and assistances you have received.  What a wonderful forum, though I have contributed nothing.

It seems like a romantic comedy and all ending in happiness, well done and keep up the good work and looking forward to your next chapter.

Neil

[shane wescott]

No worries Neil, glad you enjoyed it, I have certainly learnt heaps thanks to the Alfa Brains Trust.

Always happy to entertain but no, I don't stuff up deliberately just to make things more interesting :-)

For those who have never seen in side an L-Jetronic ECU here is a picky with my burnt out track circled in red. I am assuming this track goes to an earth hence the burn out when I connected it to 12 V and seemingly no other damage.

A couple of hours was all I could manage. I had to go out and give it another start, just to make sure I wasn't dreaming, and then had to take it out for a run.

The Beast is purring with all the glory the wonderful V6 can muster. It is idling MUCH better than I remember, probably due to all the little bits I did over the last two weeks.

Slight pinging under acceleration, that was there before and probably means I need to check the timing.

Cough and farted and spat out some smoke when I first took off, so my support car was left in a cloud of barbequed bugs and spiders. But after that she was flying.

I think the GTV6 has just thrown down the gauntlet to the Ducati - cop that Two Wheeler :-)

Catch ya

Shane