Christ this is doing my head in, I have had a fiat garage run a diag (thought a coil had gone) on my mk1 55sx(94) due to erratic rev's and miss fire when running warm.
They told me that the enginge is running weak and suggested new plugs and Lambda sensor.
I went and got myself a genuine lambda sensor and some bosch plugs but alas the problem is still there. The parts place where i brought the Lambda from said it sounded like the ecu or possibly the cat

Any ideas people????

Rob

I think you have to use denso spark plugs,also worth looking at the HT leads.
What were the results of the diagnostic tests?

shadders_SX said:

Christ this is doing my head in, I have had a fiat garage run a diag (thought a coil had gone) on my mk1 55sx(94) due to erratic rev's and miss fire when running warm.
They told me that the enginge is running weak and suggested new plugs and Lambda sensor.
I went and got myself a genuine lambda sensor and some bosch plugs but alas the problem is still there. The parts place where i brought the Lambda from said it sounded like the ecu or possibly the cat

Any ideas people????

Rob

Click to expand...

If it runs lumpy,like it on three cylinders,then it may be a coil going faulty,get someone to pull a plug-lead off,using proper h.t.pliers,one at a time when the engine is running,if the revs dont alter on the lead pulled off then the fault is on that cylinder,you should here a spark when the lead is held about half an inch away from the coil,and also see a spark as it jumps from coil to lead.If u see or hear no spark then the coil is probably no good.at worst i have known engine e.c.u.,s cause the coil to stop working.Try this but be carefull not to get a shock off the leads,use a proper insulated plier to hold the leads ok!

could also be air leak from loose throttle body etc... spray some wd 40 or spay type injector cleaner around the throttle body whith engine running if engine suddleny gets faster as you spray thats where leak is,

Ezi-Start would be good for that too, although there's a small chance of blowing yourself up with it