hi everyone,

i have a fiesta rs1800 engine in my escort which is misfiring REALLY BADLY! i have changed the spark plugs and checked the air flow censor. when i floor it, she runs fine but will misfire almost all the time otherwise.

i looked at the leads and one of them is of a different type but i havent changed the leads since i bought it and it didnt have this problem previously.

does anyone know the spark plug gap on a bosch plug? i can only find the NGK reference and setting the gap to 0.75 has only made the problem worse.

one of the leads also likes to pop itself off at the distributer end but when its put back on, it doesnt help the misfiring much.

any help.....???

thanks for looking

 

bad for coil packs and leads,would make these first thing to check,also is plug gap not 1mm,if that doesnt cure it,then you could be looking at sticky valves,they were notorious for it

 

yep change coil pack and leads.... got to an autofactor not that bad on price

 

Check lambda sensor and catalytic converter as well

 

Right. Firstly it probably has no distributor, and you are prehaps refering to the coil pack? these never go wrong and are bullet proof unless pysically broken or cracked by being hit by something. NEVER change just the plugs, always change both the leads and the plugs as you will not know which are at fault. If this does not cure it then i suspect it may be "jacking up" the lifters, sometimes refered to wrongly as sticky valves. When ford designed the engine they fucked up, and subsequently invented a thinner oil (5w30) to stop the hydraulic lifters from jacking up when cold, this may not be your problem as this is WORSE at higher rpms, not better, If it had this problem then an oil change to the correct oil will cure, or certainly make it better. Failing that you have an engine management problem, either coolant temp sensor or IAT sensor, throttle pot or map/maf sensor is at fault, or the related wiring to such devices is faulty. Diagnosing a problem like this without seeing the car is near impossible, especially over the web where conflicting and sometimes incorrect advice is given.

 

thanks chaffe,

really good advice. the misfiring has actualy stopped now. I re-gapped the new plugs a couple times at different size gaps but also the starter motor was found to being only held on with 1 bolt, loosely. I havent found what curred it and a loose starter doesnt sound like it was the culpret but it is cured, so thats what matters.

thanks for the advice!