hi guys yet another mis fire question from me lol. when i go on short journeys lik 3 miles away i get a miss fire. when i start car up again it miss fires till i drive a good few miles to clear it again? any ideas people

cheers rob

 

Give me 10 minutes till i get my magic ball out and give it a rub just to find out what car you have.

 

lol oops my bad 1993 wrx
simtec anti lag
blitz spec r
k&n
fmic

 

any mappers around

 

any0ne

 

surely some 1 has an idea

 

Has it just started doing this or have you done any mods in the run up to this starting to happen...

 

na only just started don t normally take it on such little runs

 

You're probably going to need someone with Simtek experience, and ideally the mapper who sorted yours out here.

The obvious culprit would be a faulty coolant temperature sensor but there are so many other potential explanations, without first-hand access to the car I may as well be playing a game of pin the tail on the donkey.

Presumably the Simtek has a datalink/datalogging capability so you should be able to check the coolant temp reading - as well as any other data items that are obviously outside the expected range.

As a matter of interest, if you start your car, drive around for long enough to clear the problem, park up for a minute or two with the engine off, and then restart, does the issue come back for another 3 miles (etc) or is it fine from that point forward?

If you can stop and restart with the engine fully warmed up, and it behaves itself, then the implication is that whatever's causing your problem is heat related, so either the temp sensor, or something else under the bonnet that doesn't work right when it's really cold (coilpack on its way out, or some loose wiring connectors for example).

 

ok il speak to my mapper think he enough of my car lol. i drove car tonight the problem didn t go at all this time. when it cleared a bit still hesitated in boost just felt like there was very low boost.Only thing i can think iv done to car recently is top up oil but doesn t seem to be over filled or anythink any more ideas splitpin how can i check coolant sensor ? thank you

 

do subaru just not like short trips to the shops ?

 

Can you identify which cylinder is misfiring ? If its just the one cylinder check the spark plug, coil, feed to the coil and if its still there do a compression test.

 

i had a look again at the plugs (7 s) 3 light brown 1 plug sooted but it had a black line like if it was arking out of the white bit near the electrode.changed it with a spare 6 i had it miss fired for a bit then cleared but on boost it still judders(miss fires) det light flashing to sometimes any ideas ?will do compression test prob tomorrow.coil packs seem spot on no cracks ect thanks for all help

 

any help please guys car driving me mad seem to of got rid of mis fire now but hesitatin like mad in boost.Cleaned boost solonoid ect. when i put foot down all i hear is puff puff lol