car keeps running on!!!!

[leigh7005]

sigma engines had a comon problem with exesive carbon build up on the valves what you do is you take the air clener of get a cople of capfuls of brake fluid hold the engine at 2000 rpm and tip it down the carby that should work also try hold the revs at 2000-3000 cover the carby with your hand it will suck reall hard just until its about to stall and take your hand off the carby just make sure you keep the revs up it might be shit in the jets this should solve your problem

[triton]

sigma engines had a comon problem with exesive carbon build up on the valves what you do is you take the air clener of get a cople of capfuls of brake fluid...

Brake fluid? Are you sure? Is that safe? Will it eat any of the seals or gaskets?

[leigh7005]

yes its fine i have done many of times

[81pw]

its has a new head. and ive just rebuilt the carby. cars going to the tip where it will be useful as a metal square

[leigh7005]

just try it what have you got to loose its not going to stuff anything and try the flood with hand trick let me know how it works

[81pw]

ive tried it all thanks mate

[DanTurboLancer]

Ok been interested in this for awhile now to find out the outcome, so please dont send it to be a metal box just yet ;)

So you have established that it has had a rebuild,
New head, new and rebuilt Carb...

New Dizzy, plugs...

Is the fuel Pump still the mechanical?
Has that been checked?

Are you sure its not electrical?
are you running points or Electronic ignition?

You said its running lean.
Because its running out of fuel in upper revs or under load in upper gears?

Then next thing i might be checking would be abnormal stuff like the Charcoal canister blockage,

Fuel tank filter/air bleed....
If it is blocked then you get too much vac in tank and wont let fuel flow...

Fuel filter blockage, but im sure it would be new..


If it if running lean then there couldnt be too much of a prob aside from your fuel system....

[81GL]

Don't send it to the grave yard yet... not for such a silly problem. (although they can be frustrating lol)

Could probably rule out the vacuum in the tank, fuel filter blockage etc, as these would normally show up at high rev's, which he said it runs fine at?

its an astron, so is electronic.

Its interesting how things seem to change when the carby was opened up, might be time to get a carby rebuilt, even if by a shop that does them a bit..

Nick.

[leigh7005]

did you make sure all the jets were tight and the float level is right.just to let you know my mates sigma was doing this and i fixed it buy the choke it was stuffed and carbon build up on the valves try wiering up the choke and using brake fluid down carby and adjust the fuel mix screw youll get it right.and my mates car was running on in gear for ages where you live adelaide? i could take a look for ya?

[81pw]

live in sydney lol. thanks anyway. yea i might have to take it to the carby place down the road not cheap tho 400 for rebuild plus if they find abything else needing to be done.
yea its mechanical fuel pump. gonna put a electris one on soon once i figure out this problem. thanks for everyones help

[81GL]

Why do you want an electric one?? the mechanical ones work fine.

Hmm.. maybe you could throw a wanted add up for a "100% known working carby" ?

Surely someone has a decent solex?

Nick.

[tandanus]

Yeah, dont trash this ride - youve got us all going, like
What is wrong with this thing??
T.

[astronturbo77]

hey my only advice is as follows, when i first ran my aston i had runnign on problems, they were caused by excessive carbon build up on the top of all pistons, when the engine was hot you would switch the ign off and the engine ran on backwards for several seconds! this is also helped by too much ignition timing advance and poor quality fuel. i removed the cylinder head and removed the carbon build up which was about 1.5mm thick! as soon as this was sorted and with some decent fuel i have never had the problem again. Also i havent read the start or the thread but have you inspected the pistons whith the head off?

cheers hope that helped.

[zabatron]

what fuel are you running car on?I had similar run on problems when hot with GE 2 litre a couple of years ago...problem went away with use of 98 octane fuel..not cheap I know..but i also tried everything to solve problem and changing to higher octane fuel fixed it straight away..worth a try.

[leigh7005]

brake fluid will take the carbon off its like when you put water on a hot plate same effect

[DragonCypher]

Hijack time

Ok I just put a 4g52 L200 motor in my scorp with a 4spd chrysler sigma borgy behind it

Its in, its running.. its smokey

I can turn the ignition off, and pull out the key, and it keeps running permanently, and is still drivable

Have to either block the air intake and choke it (that was when the gearbox wasnt hooked up) or put it in high gear with handbrake and stall it..

Was kind of amusing though



PS: Higher octane fuel gets better mileage too, I found it to be cheaper due to the km's/L used


more PS's: I saw vaccuum lines mentioned somewhere, my vaccuum lines for the dizzy arent connected to anything, they split long ago so I just removed em (never had this problem on the 2.6)
and
The ignition/starter motor and all that.. virtually everthing except block/head/gbox is original
Even the exhaust and webers are on that were on the 2.6
2.6L Magna distributor is used and was set statically, will be checking/adjusting in the near future

[81pw]

well turbo goes on soon so i thought i would put a electris one on cos im going blow through. but ill put a full tank of 98oct full tomorrow see wat that does. and getting a new carcoal canister

[81pw]

well turbo goes on soon so i thought i would put a electris one on cos im going blow through. but ill put a full tank of 98oct full tomorrow see wat that does. and getting a new carcoal canister

[leigh7005]

also drop your idle right down

[shuggy]

Hijack time

Ok I just put a 4g52 L200 motor in my scorp with a 4spd chrysler sigma borgy behind it

Its in, its running.. its smokey

I can turn the ignition off, and pull out the key, and it keeps running permanently, and is still drivable

Have to either block the air intake and choke it (that was when the gearbox wasnt hooked up) or put it in high gear with handbrake and stall it..

Was kind of amusing though



PS: Higher octane fuel gets better mileage too, I found it to be cheaper due to the km's/L used


more PS's: I saw vaccuum lines mentioned somewhere, my vaccuum lines for the dizzy arent connected to anything, they split long ago so I just removed em (never had this problem on the 2.6)
and
The ignition/starter motor and all that.. virtually everthing except block/head/gbox is original
Even the exhaust and webers are on that were on the 2.6
2.6L Magna distributor is used and was set statically, will be checking/adjusting in the near future

sounds like a short.. to your dizzy.
but then wouldnt your battery be dead all the time?
unless the dizzy is shorted nd only conducts when the rotar is touching the contact...
does your coil get hot?

and when you say keeps running you mean nothing changes in idle when switched off? still same revs etc?

does the ciggy lighter work when swithed off coz if it does you deffo hav a short somewhere...

[DragonCypher]

ciggy lighter is stooged.. never worked


and whilst the car has been on the hoist at tafe it has run flat a few times (we have plug innable wall chargers) so it very well could be shorting somewhere
But being old, and gone through a fair few owners.. finding the culprit wire could be difficult.. theres cut wires hanging everywhere, and all the rest are ziptied together.

If i disconnected only 1 terminal after the car was stopped, that would save the battery yes? just so i can drive it home before fixing it

Will check today about coil temperature. And what i mean with 'nothing happening' is just that.. keeps idling at the same speed, responds normally as if its still turned on. Can even drive down the street and back with no key in there, just needs to be forced to stall in order to turn off

(my apologies 81pw, I just don't feel 2 threads on the same/similar topic are necessary , I hope you understand
Good luck btw)

[shuggy]

do u have a radio in the car? or even the hand brake light. if the handbrake light stays on when the car is turned off (when the handbrake is on of course) then your ignition barrel is farked of shorting (or somewhere along that wire)
but if its not then you have a shor in the bonnet.
if that is the case easy fix unwire starter, coil, dizzy and rewire. if its barrel just take out n have a look or replace. if neither get a new car ahhaha

[tandanus]

Have we established that the ignition is off when turned off? If not, pull a spark plug, rest it on the block, start the car (yeah ), and get someone to turn it off while you look at the plug. If its firing the ignition isnt off.
I love this thread The truth cant be far away !
T.

[DragonCypher]

ok well after some messing around we determined the ignition DOES switch off with the key, however its the alternator which is still providing power to the engine..

On a spare alternator there is 1 ring terminal and 2 blade terminals, 1 wire with ring attachment, 1 wire with blade

we figured the blade was on the wrong terminal.. but cant find the 2nd one on the alternator in-car
drove it home though.. and will be reassembling as much as i can this weekend, might check the wiring at the end if i get bored

Main thing is it still drives, and can be stopped by stalling it with the brakes on
And with the handbrake light.. comes on with ignition switch, but isnt recognised when the handbrake is still on - i think its unplugged still


-
Chris

[ursuperhero]

Hi is anyone still active on this topic? 6 years later lol .. id like to make my sigma run after the ignition is turned off.