Odd cutting out

[clee]

The V6 I have in now runs and is piped up back in std form .It starts and will rev and tick over freely for ages. 20 mins etc with no issues .
But ...as soon as it is put in gear and driven it gets about 500 meters/20/30secs then just cuts out and will not restart for about 1/2 hr .It will then fire up on the first turn and if moved do it again
If I don't engage gears it is fine again and will idle bob-on .I think it is losing spark every time .So I'm thinking tdc is moving about or the ignition module/wiring ?
It has got a modded ECU on and bigger injectors but it ran fine on that setup for 6 months beforehand .
Any other possibles ??
It was booked in for MOT but never made it

[paul b]

check all the earth's...and then again....might have enough juice through the throttle cable to idle...

fuel....has it got pressure ????

air pipe pulling as engine rocks , allowing air into system...

all idea's pulled from the sky Clee...lol

[Tony Walker]

sounds like fuel starvation, check filter easiest step first. kinked pipes, pump supply voltage and earth? will it rev while not moving or does that make it cut out?

[clee]

Cheers guys .
It will rev fine when not moving .It doesn't splutter or cough just dies ......but then the fact it will right itself after a while is more fuel ??I think it is spark rather than fuel though .

[markey b]

my 5 did something similar, was crap from the inside of the fuel pipe falling apart, and was blocking the needle valve, but i know yours doesn't have a carb so not sure how it could affect it in the same way.

mine would idle fine but didn't like being under load (when it would empty the bowl) and just cut out

[clee]

I've got the rear up on stands so I can test it without having to tow the fecker back every time
Could be fuel or pump relay related but I'm pretty sure I lose spark ...I will try and replicate it and check for power out the module .

[warpspeed]

Does it have a single coil? could be overheating with the load on it, try another if you have one, i came across this problem on a tvr and a new coil cured it

[clee]

I've got a spare ignition module .Will be testing today and see what happens .Thanks

[clee]

even more now ....It will run fine out of gear ,revs ,idles no worries .As soon as it is put in gear it will run fine for about 30 secs then will just die .
I got round the back in time to hear some arcing sounds but couldn't determine where ...I've now removed all the dodgy wiring for boost controls , permanent running of all the fans/charge cooler pump and engine bay fans .Spliced in ****e everywhere tapped off wiring from fuel and injector relays and fused earths so that is now all disconnected and back to std so I can try and trace it down .
I might be calling the local mobile sparks soon if I get nowhere .

It will run through the gears fine ,only took it up to about 3k so no boost is being seen it just cuts out with no warning but will restart after 1/2 hour .....No hose leaks ,nuffink .Ig module seems fine ...

[warpspeed]

What resistance are you getting through the plug leads?

[clee]

No idea .

I have just been given some info from the owner though ...The bigger injectors have an extra earth to one of the relays The AA installed it for him
That'll be the fused earth I've pulled off I need to talk to the ECU modder fella

[clee]

Could a dodgy throttle pot be the cause ? I'm going to run it out of gear but keep it at half throttle .Definitely something buzzing on that side when it conks out .........

[tiff_lee]

The thing that strikes me as most odd is the approximate 1/2hour before the car will restart, Is there an electrical component that could be overheating requiring that time to cooldown?

[clee]

Yeh, it is weird and would point to something sticking or cooling down .I can't find anything that would move or change by being in gear so it must be position or heat ....
I hate electrics ,especially brittle , crunchy 20 year old French electrics ......

[tiff_lee]

Yeh, it is weird and would point to something sticking or cooling down .I can't find anything that would move or change by being in gear so it must be position or heat ....
I hate electrics ,especially brittle , crunchy 20 year old French electrics ......

ha ha yeah this is why I decided to rewire my 5 but then that was an easy choice considered its stripped out for track etc.

The only reason I suggested that is because there must be some significance to this 1/2 hour delay. With fuel starvation or even dodgy leads yes the car would cut out but then it would start afterwards almost immediately.

[MFaulks]

Lee,

No throttle pot on this, it just has throttle switches - idle position, and 3/4 throttle for full power map. Rather crude, but don't really see this being route cause of your problem.

The injectors JV has fitted are lower impedance than std, so they will draw more current, and consequently more heat dissipation in the ecu. There is a current monitoring circuit built into the ecu, and this will cut injection. But I don't see why it would only do this when it's driving, and so rapidly - well there is load and duty cycle, so could happen I suppose… yes ummm

The injectors were purchased from the cheap as chips vendor that JV could find.... so no idea what you have got there. If they are not opening fully to close the magnetic circuit, they will pull more current..

JV’s wiring is burned out, he had fried an ecu previously, total melt down, but this had the ART bodge inside. Unfortunately JV’s car is a bag of worms, and think you will need to know exactly what is good i.e. put in by you (including wiring), and assume nothing of the rest.

I suggest minimising the connected wires to the ecu to those only necessary to run the thing - Ignition amplifier, throttle switches, TDC sensor, air temp and water temp. Put in a set of std injectors, std chip and go again. When I get home I can send you the ECU pins you can short to bypass the injection current sensing as well, but wouldn't suggest doing that with JV bargain basement jobbies still in there… just be another ecu down the drain, it was the output drivers for the IAC last time.

You mentioned he was going through dizzy capos and rotor arms rapidly, can’t think why?

[clee]

Cheers Martin

I have already started to pull the 'extra' wiring off to try and make some sense of it all ....
Got some new bits so i can rewire the dodgy bits .Think as you say I will need to take it fully back to std before I get anywhere .

[MFaulks]

just a thought, is it runing an adjustable fuel reg or std stuff? If adjustable has it been put (back) in correctly i.e. fuel flow direction etc, daz Laws had their's wrong and did a similar thing I think, could be remembering wrong though

[MFaulks]

oh... watch the fuel rail fastners, think Jon stripped the threads on one or more and glued in with epoxy

[clee]

It just gets better and better ........

[MFaulks]

...As soon as it is put in gear it will run fine for about 30 secs then will just die ...

I got round the back in time to hear some arcing sounds but couldn't determine where ...

Definitely something buzzing on that side when it conks out .........

which side Lee, can you tell? Does this car have ABS? This is the only thing I can think of that would change state &/or receive a signal with the car in gear Reversing switch... but that's bizarre, well whole thing sounds like a 'mare..

[clee]

Throttle switch side .....I'm going to run it today and see if I can locate ....

[Scoff]

Lee, these bigger injectors, are they lower impedance than the originals ?

Should they have been fitted with a resistor pack ?

I've seen ECU's cut out when the injector drivers (in the ECU) over heat. It might take 30mins for them to cool enough to run again. And if you think about it, the injector duty will only start to rise once you get some load on the engine, perhaps why it's not cutting out at idle and no load.

Can you stick standard injectors in and test again ?

As for arcing, dunno, that doesn't fit with my theory

Just thinkout outta the box

[clee]

I'm going to run it at 3k out of gear and see if it cuts out .....I can do that from the rear so will be able to listen out for nasty sounds


Yep ..next stage is to swap chips and injectors back to std .

[MFaulks]

oh - this is IAC valve side then, you need to find the positive feed to the valve and isolate, it comes off the fuel pump relay +ve output, and same point as feed for the injectors (ecu pulls down to ground not feed +12V). Suggest disconnecting the pins on the ecu to completely isolate the IAC circuit (pins 23,24 ). Throttle switch feed is ecu pins 8, and 25.

Go back on one of JV’s old posts on RAOC, you will see the burned mess of wiring I think. Likely that side of the loom has multiple faults, shorts etc. As those wires over heated, it is likely they have caused damage from that point back, and likely bad spots / hot spots would have occurred where the loom is tightly bunched - going through the bulkhead would be my guess. Don't envy you on this one. PVC is such a cheap shizer insulation material, it's only rated 70degC, cold flows, goes brittle you name it. I'll dig out some nice Raychem Type 44 for yours and mine coz this is going to be an issue I think, as they get older...

[clee]

I'm a bit pissed off that I sold those looms to the Euro dudes
Not got any left or I would have swapped it by now .......Hey-ho we'll see how it goes ..

JV has rewired the valve already ...The supply is still in the old loom but he has put fresh wire in for the other two .....

I might have a word with a fella that supplies all that sort of thing and ask him to bring a few bits along the next time we meet

[MFaulks]

.. are they lower impedance than the originals ?

Should they have been fitted with a resistor pack ?

Hi Chris, yeap they are, think around 1.9ohm (from 2.5 ohm std-ish, Renix is a low impedance driver with current fold-back, shouldn't need a resistor pack) is what Jon told me at the time I think. But did run for sometime ok. He had a turbo fault, pulled it all out and some other stuff as well (burned out IAC wiring and solenoid...), and everything has gone from bad to worse since then I think. It is a total mess...

Personally I think he needs a new loom and throw the old stuff out. You might get it going ok for now Lee, but my concern would be you will never see the back of it, as one after another e-trickery faults are going to keep appearing... he needs to spend some spondunas and have you sort it one time and properly IMO.

[MFaulks]

I'm a bit pissed off that I sold those looms to the Euro dudes
Not got any left or I would have swapped it by now .......Hey-ho we'll see how it goes ..

Do you want to use the one I dropped to you in with my stuff? If it gets it done use it Lee, not worth the agro. Try and get Jon's out in one piece then, so have I something to copy.

[clee]

Didn't know there was one there or I would have nicked it already

Will see how it goes today if I ever get out there ...On kid and Shop duty today

[MFaulks]

thick plastic black bag (droped it down by your car next to my suspenders stuff), think it has a couple of engine looms in it, but only one is GTA I think. Have a look-see

Ha-ha+ enjoy

[clee]

Thanks I'll have a look .

[clee]

25T and the ECU plug is frazzled Martin ........

Getting somewhere ...Injector relay is tripping out ...

[MFaulks]

ok, 2 possible configs:

2 relays - Fuel pump relay (493) and Injection supply switch relay (381)
3 relays - Fuel pump relay (493), Injection supply (381), and Injection safety relay (132).

If 2, short ecu pins 6 and 7, this will hold the injection supply relay in when the fuel relay o/p energises and will disable any ecu protection circuit for current limit in the ecu injection circuit.

If 3, easiest thing to do is add wire between fuel pump relay coil neg (pin2) and ecu pin 6. Then also short between ecu pin 6 and 7 as above.

Turn key and tune for maximum smoke... only kidding

I do suggest you isolate the old +12V feed to the IAC valve, as that damaged wire is sitting in the loom juiced up and looking for something to short against if it isn't already...


postscript edit - for 3, easier to pull relay 132 and perm short the connector pins 3 and 4, and then connect ecu 6 and 7 together. Hope this helps.

[tiff_lee]

25T and the ECU plug is frazzled Martin ........

Getting somewhere ...Injector relay is tripping out ...

Ah the gremlin has been found! at least you are now making progress

[clee]

The holder for the injector relay is fecked and bodged up .I have a new base that I will wire up .There are 3 relays but only two connected to the engine/ecu loom ...The other seems to go straight up to the front , I think it is screen heater .
The IV wires are just chopped near the plug and the new ones just spliced in with them chop in type blue things .The +12v is still used from the old loom .

If the rewire doesn't work then the loom will have to come out for a proper gander .

[tiff_lee]

The IV wires are just chopped near the plug and the new ones just spliced in with them chop in type blue things ]

Oh dear that sums it up the bodgers have been in! sounds like my five with its 3 core household cable and some choccy blocks.

[MFaulks]

like my five with its 3 core household cable and some choccy blocks.

I've heard it all now, surely not twin + earth?

[clee]

Rite-so .

Rewired relay and it now fires up every time without fail but conks out after 5 secs .I can hear the relay click just before it does so .
Suggestions ? The idle valve live is fed from injector clumping if I read this right .If so would that match Martin's theory of a short ??
inj.pdf

[clee]

Can someone just confirm that I should not be getting continuity from both injector pins to the idle valve middle pin ??
I'm also seeing it between injector pins .

edit ...and not on my GTA loom so we may have found the problem .........I just needed to talk it through

[tiff_lee]

I've heard it all now, surely not twin + earth?

[clee]

That'll be a no then

Injector in and it does indeed make a circuit so pulling the loom apart was a waste of time but does rule it out .
I've swapped it back to std ECU chip and injectors and it fires up now and will idle and rev out of gear as before but still fecks off when put in gear and run

I've now pulled the CAS and the wiring on that looks dodgy as well ...I fast reaching end of patience ....
What would happen if these two touched ?? Spliced in bodge halfway down the cable and the kink has worn the insulation ....My guess is it would conk out and then when they relax a bit and separate it will fire up again ??
I'm plagued by lots of unrelated dodgyness I think

[clee]

Seems OK now
New CAS installed and no conking out .The ECU mod will need further investigation as that is still playing silly buggers but I can get the car MOT'd and see where we stand from there .
Thanks all for the input

[MFaulks]

Sorry Lee wasn't looking, loads of crud at work resulting in late nights, so not been on here to look. Seems you are ok now. If you get stuck just call me, it's not a problem at work, I'll just take 5.

When buzzing looms, you really need ecu, all sensors, and components disconnected, as you will have all sorts of sneak paths through other items otherwise. You can then just look for short and open, and insulation if you have equip to do the test.

I think it was likely the CAS was going wide open then somehow, same as cranking the throttle open.

Glad it's getting better, stay happy!

[clee]

MOT fail on a trackrod end and binding rear caliper so Electrical gremlins sorted
I'm just debating whether to put the modded ECU chip and bigger injectors back in and try and sort that extra earth millarky