im stumped so very very stumped rac 4 mechanics a dyognostic and a dyno still nothing

[smokey_dj]

ok ppl as the title says we are all well and truely stumped

my vn was getting to 1/2 way on the temp gauge idling like a pig and then cutting out completly wait till it cooled down and i could start up again and if i kept it running get it to where it need be

now this is whats been done to try rectify the problem and where im at now
coil pack and dfi (thanks matty) second hand but was working b4 changeover

CAS = brand new

ECU = brand new

and thermostat = brand new

now ECU and termostat were done yesterday while waiting for the car to get hot for the thermo to open to bleed the system through it did it it died and now it will only stay on a few seconds and then do it again

now ive had this car dynod to try find it with full sensor test everything

its been gone over by about 4 other mechanics who couldnt find anything

i now have 4 of the local RACV service mens direct contact and on first name basis cause of this

one of them yesterday checked when it was playing up as i describe

fuel reg
fuel pump
dfi wireing
certain elec wires and clams and so on
clamping off fuel return line
and thats about it

the car had a dyognostic done by lubemobile and that revealed code 12 (everything Aok) but they said the ECU could just be old and lying so it got replaced as i said

im truely lost can anyone please shed some light on this its bringing me to tears now thinking theres nothing i can do

[Doctor Bob]

what is missing when it wont start?
fuel or spark?

[smokey_dj]

nah its actually starting then cuts out

ok ill give a better example of what it was doing

i could run the car fine like nothing was wrong anything below a 23 degrees day but if it got to half way on the temp gauge at anytime (sitting in traffic long sequence of lights) it would then start to idle like a pig and then just cut out and die then i couldnt start it for 40 or so mins but after i could again i could keep it running and then get to where i need it to be (if it didnt get to 1/2 way again

at night not a hassle but now since thermo and ecu was done (though it was hot yesterday) it will start run then just cut out again

its got so many ppl stumped
btw its a 91 series 2 vn

[Doctor Bob]

what is the fuel pressure when it plays up?

[Hillerus]

Have they checked to make sure your fuel isnt vapourising at all?

[smokey_dj]

actually doctor bob i wouldnt know
i just had my local now becoming like a mate lol RACV guy round here yesterday and he clamped the line off to check if it was presurising enough to which he said it was

if it helps any answer my air fuel mixtures were perfect while being dyno'd 14.1 or .6 i forget which was perfect but was told it was from a mechanic who is very well known respected and doesnt talk shit to you he is also a BROCK specialist

this whole post maybe useless but im still learning about cars myself as things go wrong

[Doctor Bob]

he shoould be checking the pressure to see if it has enough
the dyno readings are pointless really if it was running ok at the time
it needs to be checked when it faults

[smokey_dj]

thats the problem getting it there when it is faulting when we got it there d/c'd the fan to heat it up still didnt do it AHHHHHHHHHHHHHHHH

[smokey_dj]

ok i got a mate coming over who is probly gonna annoy the shit out of me but oh well we are gonna take the throttle body off and give it a clean and go over a few other things

can anyone sugest while we are out there anything else we should take off clean have a look at ect or what to look for

[CAM05L]

i dare say you may have a cross blown head gasket which will play around with a few things like your talking about and sometimes can be quite difficult to detect. check your radiator to see if it has any crap floating on yhe to near cap and even a bit of water coming out your exhaust while your to perhaps aid in your prosess of elimination

[Doctor Bob]

i dont hink cleaning anything will help
it is either a fuel pump, filter or an electrical fault

rob

[AirStrike]

My car (the SS) was doing the exact same thing. I replaced both fuel pumps (V8 runs and intank and external), MAP sensor, Igntion module and still did it!!
Finally I replace the ECU and it hasnt missed a beat since. Did you use a 2nd hand ECU or a new one? Speak to Repco mate they do a change over one for $150 or so.
AirStrike

[smokey_dj]

bursons brand new trade price 119.00 but with 100 change over for the old 1

brand spanker ecu with my old memcal done yesterday still doing it

fuel pump and fliter 6 months old or less

i really truelly am stumped

doctor bob can i add you to msn to discuss this all with you ive seen your answers to alot of ppls problems and just guiding them to the help they need otherwise maybe it might help to get realtime answers to queries either of us have ???

[88GreenVN]

Could be an earth problem. Check them all. The plug into the ECU can also be a problem. Connector to the DFI unit - close the pins up a bit.
If its a Calais check the Security lock inside the glovebox.

[smokey_dj]

dfi got checked

ecu plugs got blasted out incase there was any crap in them

all the earths...i was hoping it didnt come to that

but the car is a 91 vn sedan series 2 executive

my dad came up with an intersting theory when it got dynod we disconnected the fan to get it hot to see it if would cut out and no it didnt

dads wondering if there could be something to do with the fan itself ???

[88GreenVN]

dfi got checked

ecu plugs got blasted out incase there was any crap in them

all the earths...i was hoping it didnt come to that

but the car is a 91 vn sedan series 2 executive

my dad came up with an intersting theory when it got dynod we disconnected the fan to get it hot to see it if would cut out and no it didnt

dads wondering if there could be something to do with the fan itself ???

I had the laptop connected to my VN when driving around for a while and the car died when the fan was called in by the ECU. Put the data into a excel and overlaped the info. It looked like the fan had killed the motor.

I replaced the ECU, Disconnected the security lock in the glovebox, ran a wire from the ignision to the ECU just in case and replaced the CAS, MAP and DFI unit. Also replaced leads n plugs.

The last thing to stop the car from stalling was the ECU. It was not the fan but when I disconnected the fan the car did not stall.

[Garth]

being that from what you have descirbed it can realy be only one of 2 things, you have a fuel system failure, or you have a faulty connection in the wiring loom.

when it stops next time, what you need to do is quicly rip of a spark plug, and start it, if it has a spark you can see let us know

im thinking that from what you have described to me, it's doing what it's ment to do, gets hot, and as it gets hot there is a hot or dry solder join in the cas cct or dfi cct somewhere, which will cause the open circuit, it cooles down, circuit is made again, all is good.

[smokey_dj]

ok break through and funnely enough it was made while cleaning out throttle

now took off everything from the throttle back to the hose and pod to clean it out with a spray in throttle cleaner

the car ran with no hassle :S but did still show signs it may die

put the hose on and it died but not as fast

put the pod on and it died about the same with the hose on

now the engine light is coming on too

i booked lube mobile for a dyognostics on mon morn as now its finally showing an engine light so maybe we might get some resaults this time

[immortality]

test for codes yourself and post the results here. sure somebody will then have an idea. don't bother pulling a spark plug out next time it dies, just carry a spare one in the car. saves a lot of time. open the gap up also as the spark will jump the normal gap no probs in normal atmospheric pressure. mount a fuel presure gauge in the fuel line and leave in place until the fault is sorted that way you can get an instant reading next time the problem occurs. have you looked at the MAP sensor at all.

[HoZy]

I know ur problem....... Injector wiring on one of the plugs, It's shorting one when gets hot wires flex, cool down harden up.....

Just fiddle with all ur injector wiring a lil bit an start it, run it an see how she goes..... I had that problem other day aswell... Fixed it all now though.

Cheers
MaT

[smokey_dj]

ok well some wiring on my car needs some looking at anyway so my mate is going to go over my car top to bottom and install this new kill switch technology he and his mate designed for all up $300

thats going over just about every wire in the car from what we have agreed on that wil be done sometime this week Z

my baby needs some very urgent TLC

[HoZy]

i keep reading this thread title as
"i'm stupid, so very very stupid"

[xcop5l]

it could be going into limp mode thinking its over heating and shutting down

[HoZy]

No, You can drive a car in limphome mode mate, I've done it.

Cheers
MaT

[immortality]

I know ur problem....... Injector wiring on one of the plugs, It's shorting one when gets hot wires flex, cool down harden up.....

Just fiddle with all ur injector wiring a lil bit an start it, run it an see how she goes..... I had that problem other day aswell... Fixed it all now though.

Cheers
MaT

that would explain it running rough once it gets hot but does it also explain the whole engine dying? faulty wiring/ bad solder joints can be very difficult to diagnose