How's it going guys. I have a weird issue with my car. I always let my car warm up for about 5-10 mins before driving. Everything is ok, even to when I start driving it. The problem occurs when I start to give it a little more gas, where it it starts to misfire for some reason. It'll do this up until I start boosting and it actually boost perfectly fine. The craziest part it'll keep doing the same thing until I turn off the car and immediately start it back, where the misfire goes away and the car drives absolutely normal. Anyone have any suggestions as to what this might be? Any help would be appreciated. Thanks
Mysterious Misfire
- Thread starter Boostin 7M
- Start date
Look at the wires attached to the intake. There is a flat spot where the 2 half meet In the middle to the right I believe. Make sure there all grounded and not broken.
Engine throwing codes?
Engine throwing codes?
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You dont need to warm the engine up for that long. All it does is wash the cyclinder walls with fuel. 30 seconds to a minute is all you need.
Thanks for the replies. I'll check the wires when I get home and see what I find. As for CEL, it isn't throwing anything. I did an ECU reset couple of days ago and it didn't really help much. Do you think me running the car for that long can be a reason the misfire?
Abasoultly not low idle is a natural part of the RMP range if it was bad for a engine to "idel" then mine would have been dead a long time ago.
KTM530;1805492 said:
A cold engines piston to cylinder wall, and ring gap clearances are loose. On top of that the mixture is richer and harder to atomize, its easier for fuel to seep past the rings and into your oil.
Oh ok. Thanks for clearing that up. Someone told it could possible be my coil pack, so I have an extra set and will swap it today and see what happens. But I'll also check the wires as well
So I checked all the wires, swapped coil packs and didn't let it idle for long and drove it and still does the same thing. Breaks up up until I shut the car off and turn it back on and it's normal. I'm going to perform an ECU reset one more time and see what's happens from there. At this point I'm stumped for ideas.
Well I spoke to my cousin (he was the one that was working on my car). I had a problem with my knock sensor wiring and he didn't know and he timed the car back (had to do the HG over reason for the timing to be done over). So after I fixed the wiring and cleared the codes the motor wasn't timed back. So I think your the right track with that. IF not that, you think it might be the ECU?
mecevans;1805416 said:
I would have to argue about this a bit...
is it bad to let you car sit and warm up..... nope no harm but wasting fuel... but nice toasty car thou on a cold day.
will it wash your wall's..... no again....will it coatmate your oil I would have to say no again since the rpm rise's form air added in form the isc giving the motor a better ring seal wiht no load added
now I know with some systems with no air vavle aka isc these systems will dump more fuel then needed kinda like a carb's cold start system aka a choke
and witch can be wores then now daya days standers
a cold start injector only shoot's fuel just befor starting for an easyer start then shuts off and then you car start's in open loop tell warm
if any one wants to jump into this they can but this is what I have been told and have read
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The main problem is quenching. When atomized fuel touches cold cylinder walls and head, it condenses.
Well yae but these will go away rather fast and has nothing to do with a car sitting
I can only explain this one way since and can't not go to tecncale in because of to many factors and my lack of finer Knowledge in it ect
see when your grinding a block of steel or some thign along thous lines and go to doose the part in water with bare fingers holding the part because it not really that hot on the end you are holding then all of sudden your fingers start burning because the heat just got transfer to part of side heat sink aka the part
lets call it heat transfer aka energy has got to go some were so in this case it will stay put tell it's able to bleed properly into the block and cooling system
this plays rolls in wet liner block's and semi wet liners
I can only explain this one way since and can't not go to tecncale in because of to many factors and my lack of finer Knowledge in it ect
see when your grinding a block of steel or some thign along thous lines and go to doose the part in water with bare fingers holding the part because it not really that hot on the end you are holding then all of sudden your fingers start burning because the heat just got transfer to part of side heat sink aka the part
lets call it heat transfer aka energy has got to go some were so in this case it will stay put tell it's able to bleed properly into the block and cooling system
this plays rolls in wet liner block's and semi wet liners
So I noticed something interesting today. The coolant line underneath the throttle body has a small nick in it. Not too sure if coolant is leaving thru it but it def has a small nick in it. Can this contribute to the misfire. Btw, I'm stick gonna time the motor back b/c it needs one anyway.
Deal with the timing issue first. If nothing else... if you do have a spare ecu around... try swapping it and see what happens. Even though it's not likely the case it doesn't hurt to try because atleast you'd definitely know it may or not be the problem since you tried it already.