vl commodore auto 86

[mouse]

HELP PLEASE!!! hey my husband has a 1986 vl commodore auto, it starts n runs, after a short time it cuts out like its out of fuel. these are the things he has changed: both fuel pumps, fuel lines, petrol filter, computer n ATI box, starter motor, angle sensor, dizzy, air flow sensor, map sensor, throttle body n switch, plugs, leads, cap, alternater, injectors, heat sensor, fuel tank also tried diff petrol n it still cuts out. has anyone got any other ideas or maybe thr is something we have missed please, anyone...

[nasty1]

Does it have spark?changed coil?if it has spark is it strong?
Did he change the whole dizzy?if so possibly timing is out as dizzy maybe installed wrong.

Can you give us a description of what its doing?is it trying to start or is it just turning over?

Also buy a gregorys vl manual

[mouse]

yes we changed the coil as well, the timing is ok n he has changed the dizzy a couple of times. wat happens is it will start, run for a few minutes n sometimes he can drive it for bout half an hour n then it starts to drop down in idle like its running out of petrol then stalls, sometimes u can restart it but usually it wont run for awhile n i have to tow him home lol

[Jxw]

the power transistor on the distributor, small silver round thing with a black plug and couple of small bolts?
fuel pressure regulator?
fuse and relays all good in the engine bay, no dirty corroded bad contacts? (this has got me a couple of times in the past)

[detox_nath83]

Unplug the Air flow meter and if the car idles fine its ur afm failing...(was it replaced NEW or second hand.?

If u changed dizzy was it a whole change, meaning crank angle sensor as well(which is inside the dizzy) or moved it over....?

[Jxw]

nath, what would you say when a car won't start/idle with the afm disconnected? (just an oddball one i have here runs fine with no probs but refuses to start without the afm, in the past on other rb30's sure they'd start just not rev)

[nasty1]

its not sposed to run with the afm disconected.

sounds like your plugs are fouwling up to me

[BenDoverVL]

Also check the Oxygen sensor on the exaugst, it controls your fuel mixture. When the engine is cool the sensor runs in an open loop status which means it runs on predetermind mixture settings. Once it heats up the O2 sensor activates and allow the computer to read the gases in the exaugst and the computer adjusts the mixture accoringly. If it only has problems when it's warm it could be because to O2 sensor is sending faulty messages to the computer as it only works when it is at NOT (Normal Operating Temperature).

[detox_nath83]

O2 sensor once engine is warm goes into close loop mode as well.

if the AFM is failing it will start and idle but wont rev... if your afm is good and u unplug it,it will stall.

[Jxw]

a crook o2 sensor won't stop a car from running, just suffer bad fuel economy, also as they're a heated o2 they will be up to operating temp within a very short time of turning the key on, should be less than 30 seconds even on a cold start.

[detox_nath83]

^^^who said it would???

[Jxw]

^^^who said it would???

Also check the Oxygen sensor on the exaugst, it controls your fuel mixture. When the engine is cool the sensor runs in an open loop status which means it runs on predetermind mixture settings. Once it heats up the O2 sensor activates and allow the computer to read the gases in the exaugst and the computer adjusts the mixture accoringly. If it only has problems when it's warm it could be because to O2 sensor is sending faulty messages to the computer as it only works when it is at NOT (Normal Operating Temperature).

when the OP is trying to fix a problem with the engine stopping after a short time ^^^^^ what does that have to do with a lambda sensor?

[nasty1]

The plugs mite be fouling up and chocking it

[BenDoverVL]

Because it only affects a car when it's hot causing it to possibly over fuel or run lean. Hence why a car can run fine until it gets warm.

[Jxw]

Because it only affects a car when it's hot causing it to possibly over fuel or run lean. Hence why a car can run fine until it gets warm.

it's still not going to cause the engine to stop, maybe run like a cow with 2.5 legs but not stop, ok if it continually runs lean it might burn out a valve or put a hole in the piston, rich it'll eventually fowl the plugs after long term driving, rare a worst case scenarios.
If this was the case it wouldn't just stop working after 30 minutes, it wouldn't even start and run until the plugs were removed and cleaned. the o2 would be giving feedback within 20 seconds of starting and it won't take 30 minutes for the engine to get to operating temp, how many vl's do you know of that get 200-300 kms out of a full tank and are still going fine except the excessive fuel consumption? i reckon they'd be running pretty rich, and i've heard of a dozen or more over the years like this.

Now as the OP has replaced all the ignition components and still having the same problems, highly unlikely it has fowled a new set of plugs in 30 minutes without showing any other signs of running like crap before hand.