Hi,
I posted on here a little while ago - my Impreza (1996) non turbo was having some misfiring issues.
I took on board the advice given at the time checked the MAF and that was fine, and have also changed the coil pack and plugs but still having issues.

It seems to start better and is not kangarooing as much as before but it seems to hold back when foot is down and every now and again it feels like it is missing but then seems ok.
What else could I try to try and resolve this issue - its driving me MAD!!!!!.

Would it be a good idea to change the HT leads? and see if this makes any difference or is there other things I can try.
Many Thanks in Advance

 

Do a check on the ECU to see if it throws up any codes. If you do a search on here there are plenty of helpful threads covering this topic.
Maybe check the throttle position sensor and also the knock sensor (assuming one is fitted). Could also be fuel pressure related if the car is miss firing

 

Thanks for the quick response.
Wanted to add that the car seems to missfire more when hot.
Last time we did ECU check no codes came up and have since re set the ECU and it is still doing it.
Where would the Throttle Sensor and knock sensor be located in the Engine? and how cheap and easy are these to replace.

Thanks in Advance

 

Mine (MY99) is doing the same when cold particularly. I left it in with a respectable garage (rallying heritage) and they checked everything and couldn't find anything wrong. I've a suspicion that its the plug leads breaking down a little. Mine is most noticeable when just tipping along. At WOT there is just a suspicion that she's not pulling as well as she should. I'll report back in a week or two when I get around to ordering new leads.

Pat

 

hi this is quite a common problem on th n/a engine
what u need to do is remove clean up mating surfaces and reloctae the knock sensor.

here is a link with pics to help u out

Hesitation Problems - .:ImprezaSport.net Forums:.

good luck

jamie

 

Back Again

Thanks for the advice given, I have checked the knock link sensor (I have One!) followed the link and the instructions given but its still playing up, have changed the coil pack, checked my leads and they are fine - no breakage etc, and have replaced the plugs.

Have completed ECU Diagnostic and no codes came up so have done a reset but hasn't made much difference, the car still judders and seems to be missing - flat spots on occasions and not as muuch power as it should have.

What else could it be???
I am looking for the cheapest options to try and sort this out but money is tight.
Any advice would be great!!!!

Thanks Again in Advance

 

Unplug the O2 sensor and see if it still does it?

 

Un plugged the O2 sensor today and it was a lot worse, spluttering and pumping out smoke.

Any more ideas anyone!!!!
I am really getting Pi***ed off now.

Thanks again in advance

 

did you happen to have recentley changed or removed your inlet manifold? i did on mine and i damaged one of the coil pack cables with the main wiring harness. if it isnt that maybe a air leak?

 

I have had the HT leads looked at by a friend who is mechanic and the spark from the coil pack was running down the lead and bouncing off the manifold so bought new leads reset ECU and the problem has stopped the car is not bouncing around as before.

But still flat on occasion when I put toe down, mainly in 3rd and sometimes in 5th, but when not doing it its running like a dream.

Also just thought I would ask, when coming back from a day out about 3 - 4 mins after starting engine and driving the engine check light came on and went off a few minutes later, just wanted to know what could have caused this to happen, would I need to reset ECU again or read codes????.
Thanks in advance