occasional "stall" under acceleration - vr

[gsxrdan]

Howdy, vr v6, is in good condition overall, but she will die every now and then when i take off hard, so far has always caught again (its an auto), but this problem could get me rear-ended. Relevant points: have changed fuel filter; happens with tank full or empty or inbetween; doesn't always have to be heavy acceleration; happens hot or cold; no engine light or fault code; have run fuel system cleaner thru it; any ideas please? cheers guys.:bang:

 

[hsvpunk]

Id put it to fuel filter, and pump.

 

[VrWagz1]

Just sounds like the spark plugs are a bit old, try changing them.

 

[gsxrdan]

didnt want the expense of a fuel pump! spark plugs and fuel filter are new, poo! is there a way of checking fuel pump?

 

[5.0Ltr-StatesMan]

I have a auto VR statesman with a 5 litre EFI (as my name may suggest) Recently I have been having the same prob with the car "****ting itself " mostly while under acceleration, but also when not it just stalls & suffers pre-ignition. It will always start again & usually will generate a error code #42 (ignition bypass circuit)
It only wants to run on petrol - so cant use LPG

I'm as keen as Johnny #5 to find "more input"

Here's a few things I have pondered on over whilst being honked at & called "bloody wanker" by frustrated motorists when the statesman " ****s itself " at the traffic lights.

Faulty Maf/map sensor or a vacuum leak to said sensor which controls EFI EST & Trans ?
I say this cos I had problems with the auto not changing gear correctly not long before It started not running properly.

Bad Distributor cap/sparkplugs/leads causing weak spark ?

Knock sensor or Throttle sensor ?

EST/ECM Module running in back-up mode with only 8 or so spark timing settings ?

 

[gsxrdan]

fyi spark plugs are new. Theres another thread around with a similar issue regarding cornering and stalling - the problem may be 'swirl pot' in fuel tank breaking loose and causing fuel pump to starve a bit when cornering with a low amount of fuel - after experimenting a bit i think my issue is the same - also cant remember it ever doing it except when cornering and putting the foot down a bit? so perhaps time to find a tank at upi and hope its swirl pot's intact. StatesMan - i think your lpg issue is maybe another drama altogether, good luck!

 

[5.0Ltr-StatesMan]

OK I HAVE MANAGED TO DRAMATICALLY IMPROVE THE PROBLEM

I unplugged the MAF Sensor , if thats its name, (see pic 1) removing both vacuum hose and wiring plug. I then started the engine without them ,once i blocked the vacuum hose with my thumb it of course ran alot better, was able to rev up the engine without it stalling for once ! I gave the plastic unit (pic 1) a bit of a tap with a screwdriver and connected it back up while the motor was still running.

The car now runs a hell of alot better but still has a little trouble changin gears smoothly.im quite convinced it's the source of my recent troubles, and will now replace it with a new one!

Also I should mention just in case it may of helped , one of the ignition module (pic 2)
mounting bolts was a little loose and was tightened.

The car no longer dies upon heavy throttle & will Idle for as long as I want.
IT NOW ALSO RUNS ON LPG !!!! YaaaY !!!