ok here goes. my s2 rs turbo has a misfire. it's only small and not regular. the problem is when you are going from about 2-3.5k rpm ie coming on boost it kind of holds back and misses more. i have changed coil, leads, rotor, dizzy cap, 2nd hand dizzy, plugs, fuel pump, empa, pressure reg, etc..
checked for boost leaks. what next?
the car runs fine if you advance the dizzy but i dont want to melt any pistons.
oh yeah also went through the wiring loom and checked for broken wires to the ecu's/ sensors.

bigcry.gif

any suggestions??

cheeRS

 

I had a very similar problem on my saph and changed much of the same stuff, got it looked at professionally and ecu tested etc. Was really pulling my hair out and then i changed the actuator.... hey presto that cured it

although your car running fine when you advance the timing would lead me to believe my post is useless

good luck getting it sorted

 

If it runs fine with timing advanced, it needs to go on a rolling road, where they can optimse the timing, and use DET CANS to detect any det so that no damnage is caused.
Not all ford markings are accurate, personally the worst I have seen was 8 degrees off(TDC) mark on a pulley wheel, chgeck also your CAM TIMING first.
tabetha

 

Thanks for the replies. i am currently building a zvh so when thats done i'll get it on the rollers. i originally thought it was cam timing but i put a std cam back in and it was stilll the same, just slower lol. interesting about the actuator though. what syptoms did the car have exactly as mine seems to boost ok holds 9psi. was running 15psi but the hesitation was worse.
also even when the ignition timing is on the factory marks when you floor the throttle from low revs it pinks for about half a second. anyone else have this on their car?? doesn't pink at all on boost even with the timing advanced. oh yeah is 100 miles from 20quid normal? driving normally. plugs look ok not black.

 

You have changed the plugs, What gaps are you putting on the plugs. a lot turbo charged cars can mis fire on boost if you run to big plug gaps.



dave

 

hi mate, i gapped the plugs to .75mm tried going smaller than this but it starts misfiring more. doesn't really feel like the sparks blowing out though. just been playing with the cam/ignition timing. couldn't get the timing marks to line up properly so i put my vernier on and advanced the cam about 2.5 degrees so the marks lined up. feels quicker but still needs more ignition timing to run smoothly. do you thing it could be rich on boost?

 

Think it needs to go on rollers so it can be set up under load etc.
tabetha

 

Simple knock sensor issue. Very common. Advance the ignition until it stops bogging and you will have no problem.

 

i did try disconnecting the knock sensor but it had no effect. does the ecu assume the sensor is faulty and run in LOS mode if it's disconnected? if it does then it could well be the knock sensor. does anybody have a spare knock sensor or series 1 ecu(no knock sensor facility) i could try in the north west? thanks ray

does anyone know if a series 2 chip will work in a series 1 ecu????

 

if u bring it to stockport i can check it over for you.

 

cheeRS mate that would be a big help. pm me when your available. thanks

 

i had the same problemo on my s1 for months,i replaced EVERYTHING,plugs,leads,dizzy, arm, cap, coil, fuel pump, fuel pump relay, actuator, checked all wiring, ignition ecu,
turned out to be a balyst (spellcheck that!) resistor. a small black box dangling by the metering unit with 2 real short wires popping out of it which join and disapear into the coil wiring. i robbed 1 off an xr3i from a scrappy as a 'might as well eliminate whatever that is' and it turned out to be a stroke of genius! try it!

 

I had this, replaced coil and it sorted it.