Twellsie

iTrader: (1)

this started out as an intemitent problem, but now as soon as it starts to come on boost, it cuts the boost and back fires, anyone any suggestions?

lozi

mine was doing exactly this after i went through a large puddle perhaps something has gotten wet?

Twellsie

iTrader: (1)

that could make sense, I had my car broken into and whilst trying to steal bits out of the engine bay the contents of the water system was emptied everywere,

did you manage to track down with item was causing it?

bigchez

sure i read it on here recently dude to check how tight the fuel rail is as it works loose and as the injectors squirt more on boost it moves it, allowing air in and it obv won't combust properly.

If its not that I haven't a clue other than its a shitty old cossie

lozi

i never founf out exactly what got wet as after a couple days it dryed out and cleared up, but when i say a large puddle it was more like a lake the water came up over the bonnet lol woops

Rs1

iTrader: (1)

Crank sensor or sensor gap.

lurch1977

iTrader: (1)

Could be overboosting down to the actuator

kosman

my crank sensor ballsed up after it had rained heavy.

dovboy

+1

Twellsie

iTrader: (1)

all looks in good condition, what do you mean by gap?

STUCOS

iTrader: (8)

Check fuel pressure as well

cheeRS stu

WongRS

iTrader: (11)

is it boosting right? as said above, mine did this when it overboosted?

dom123

iTrader: (1)

i reacon you have fuel surge how old is the fuel pump? whats the fuel filter like? have you jacked the car up and crushed a fuel line?

MAD Ade

iTrader: (1)

Does your tacho needle jump all over the place when it mis-fires? If so it's your phase sensor.

Twellsie

iTrader: (1)

havnt noticed what it does at the time of the back fire, but it does idle a little higher for a while after

MAD Ade

iTrader: (1)

What coil set up are you running?

Twellsie

iTrader: (1)

Group A

Mark RS

iTrader: (13)

fuel pressure reg?

g10ens

sounds like crank sensor

Toe Knee

iTrader: (2)

the gfs car was running like shit and doing similar, xr3i so not turbo but still, put ur foot down and intermittently backfired, ran like shit and jolted like a bitch!!! Changed the fuel filter and jobs a goodun!!! she ran it dry a while back so think a bit of shit might have clogged the filter or something.

Only other poss is the inlet plenum gaskets do go as my old cossie one went and had a similar intermittent fault!! althou it did it off boost aswell as on!

MAD Ade

iTrader: (1)

Hmmm, that rules out the coil lead to the dizzy. How old is the wiring loom to the engine (cps, iscv, tps, injectors etc. etc. etc.)

Twellsie

iTrader: (1)

Engine loom I believe is still the original, but looks in good condition, CPS is 6 months old, Iscv is about 2 years old, tps unsure exactly, about 5 years, injectors 3 years, fuel filter 2 years ago.

I have never changed the phase sensor, so for the sake of 20 quid, i will give that a whirl

cossiemanden

Sounds like MAP-SENSOR to me
Been there, done that tho

MAD Ade

iTrader: (1)

I had a problem with the phase sensor a few years back, was popping and farting, the tacho needle was jumping around like mad, check this mate. If it's not this I would get your tuner to check it out.
The engine loom can look like new but they do break down due to vibration. The stranding of the cable in the loom is not that fine so the strands can fracture over a long period of time.

Neil S

iTrader: (1)

I can't believe nobody has said plugs! If they're 071s, check the little lead gaps, they rattle loose, if not, then check the gaps

Twellsie

iTrader: (1)

not long had a new one, is there anyway of checking them?

cossiemanden

They can be one day old, if you buy un-original ones and hit some water they will break down.(original ones, are more precise and more resistant against water)
There is a reason they are out where they are, and upside down.
Real time checking does recuire a laptop, but the upper symptoms sounds like it.
Also check plugs, could also be them