Hesitation/Missfire 2.0 16v

[Cupra Kid]

Hi guys, in need of some knowledge. The Cordy has developed a new fault for the week, its decided its going to hesitate and miss fire when the engines warm. Does it at low revs when setting off or when slowly cruising. Feels like its trying to go but as though its fighting against something. Had a look in the oil and theres no evidence of coolant, and no oil in the coolant tank either, so i'm hoping it cant be the head gasket. Any other suggestions as to what i could do to narrow down the fault? Finally no logs of faults in VAG-COM.

Cheers

 

[h3ppy]

i would check the plugs and leads as a start mate.

 

[Cupra Kid]

Good suggestion already had a quick look and they seem ok, plugs and leads are only 10,000 miles old so i would hope they're ok still. Do seem to get overly flexible when warm though

 

[h3ppy]

they should be fine after 10000miles but you never no!!!

i had a car that i bought with 60k on the clock, ran it for another 5 and it started miss firing and hesitating, i changed the coil packs, an egr valve and eventually we found was still on the original plugs, we didnt check them first as it had supposedly just had a full service!!!!!.......so much for the fsh!!!!! sold it after that as i couldnt trust it any more!!!

start by checkin the plugs and leads first, then i would maybe suggest cleaning the throttle body?? do all the cheap fixes first!!

this sort off prob can be caused by many things so it is hit or miss if you get it first or last!!!

 

[F2 Stu]

Dodgy crank trigger, the oem one used to be darn sporadic at times

 

[Cupra Kid]

Dodgy crank trigger, the oem one used to be darn sporadic at times

Whats this do? Would it cause issues at any RPM?

Just ruled out the throttle body, and air supply.

 

[F2 Stu]

yeah, its a common thing, tho accesss to it aint great as its behind the front engine mount

 

[myseatcupra]

mine does the same but when cold come to think of it hot as well. fells like it momenteraly cuts out then pics up

 

[myseatcupra]

Dodgy crank trigger, the oem one used to be darn sporadic at times

do they cost much??? are they easy to fit, apart from access

 

[m0rk]

1 allen key to fit. about £80 new

 

[myseatcupra]

ahhh might not try that on a whim. but thank for the info. would the freeware vag com tell if it was that

 

[m0rk]

the diagnostics ability on the ABF ECU is pretty crap.....

 

[myseatcupra]

crap lol

 

[Cupra Kid]

Well so far......................mines behaving!!! I spent last monday night in the garage with a very large can of WD40 and lots of rags. Stripped down the air feeds and cleaned with WD40 and a rag, same for the throttle body.

Cleaned the MAF sensor as well. Had every plug/electrical connection off that i could find, cleaned up the contacts with WD40 and put it all back together. So hope fully thats it cured. Touches wood.

 

[m0rk]

Cleaned the MAF sensor as well. Had every plug/electrical connection off that i could find, cleaned up the contacts with WD40 and put it all back together. So hope fully thats it cured. Touches wood.

the 16v doesn't have a MAF sensor? who's car were you WD40'ing?

 

[Cupra Kid]

the 16v doesn't have a MAF sensor? who's car were you WD40'ing?

Was my car, thats for sure. Its the sensor after the airbox thats on the intake pipe to the throttle body. I was told it was a MAF What is it really?

The problems back anyway and the car is seriously missfiring now, but only when its really hot!

 

[F2 Stu]

thats the air temp iirc

 

[edc]

Coolant temp sensor by dizzy cap

 

[Fl@pper]

Coolant temp sensor by dizzy cap

worth a look if engine temperature is a factor in the fault

 

[edc]

Says it happens when it gets hot. Had similar sounding problems a while ago and it was temp sensor.