Mk3 Cavalier Owners Club | Vauxhall Cavalier Dot Com

Hi. I have just got my cavalier gsi on the road but it has a random misfire which has caused the car to breakdown twice and the only way to get it started again was to press the pressure release valve on the fuel rack which sometimes works 1st time but other times it still misfires for a few minutes before ticking over normally. When starting the car it has a slight misfire on low revs but when driving and accelerating hard it is absolutely fine but it has broken down twice in the last week while driving at a steady speed and then all of a sudden the car starts to misfire rapidly and then it just died. I have changed the fuel pump, fuel filter, ignition leads, spark plugs, dizzy cap and rotor arm. If anyone has had this problem or could point me in the right direction of sorting it i would really appreciate it. Thanks

Hmm - just trying to suss the correlation between fuel pressure release on the fuel rail and a mis-fire.

The only time fuel will cause a mis-fire is if you have a sticking or gummed up injector valve.

Then fuel pressure made me think of the fuel pressure regulator - over pressurising maybe as it seems okay when flow rate is allowed to increase.

Just thought - engine bay heat...is the fault any worse after a warm start?

However if it is ignition related, I would look at the injector loom.
I have heard of one or two looms where a mis-fire has been caused by a loom that is old and the wiring breaking up or the connectors are dirty.

So in order of cost...

1 - Check your loom first as it is free to look at.
And probably not as expensive as the other two to repair or replace.

2 - Next cheapest is the fuel pressure regulator

3 - most expensive is to get the injectors cleaned and serviced. - or replaced.

Hi. I have now cured the breaking down as the pipe in the top of the petrol tank has rotted away so the car now ticks over and doesn't cut out but does mid/hesitate an awful lot when trying to drive normally at a steady speed but again if i accelerate the car is fine and pulls well. I just find it strange that it only has problems when at a gentle cruising speed in any gear. If you have any suggestions i would appreciate it. Thanks

Kyle21 wrote:Hi. I have now cured the breaking down as the pipe in the top of the petrol tank has rotted away so the car now ticks over and doesn't cut out but does mid/hesitate an awful lot when trying to drive normally at a steady speed but again if i accelerate the car is fine and pulls well. I just find it strange that it only has problems when at a gentle cruising speed in any gear. If you have any suggestions i would appreciate it. Thanks

Might be fuel pressure regulator as when you gun it full pressure will be used but on cruising it is cut back, or should be cut back and fuel fed back to tank more.