Car bogging down/mis-firing
Discussion
My car is running pretty rough at the minute due to what I think is a mis fire.
If I put my foot down, it will either pick up and fly (St2 Jez chip now fitted
) or will stutter & hesitate and do nothing til I lift off and feather the throttle back on.
Its worse when I change up after nailing it, as almost every time it will bog down in the next gear.
I've checked for boost leaks, its got new plugs, and the coilpacks are 100% according to the chap I got them from (on SXOC). Timing was set by Jez Horsham too, so I think its safe to assume it correct
I've also driven with the lambda sensor unplugged to see if that made a difference, and it didn't
Any ideas anyone, cos I'm a bit stumped
Cheers,
Ed
If I put my foot down, it will either pick up and fly (St2 Jez chip now fitted
) or will stutter & hesitate and do nothing til I lift off and feather the throttle back on. Its worse when I change up after nailing it, as almost every time it will bog down in the next gear.
I've checked for boost leaks, its got new plugs, and the coilpacks are 100% according to the chap I got them from (on SXOC). Timing was set by Jez Horsham too, so I think its safe to assume it correct
I've also driven with the lambda sensor unplugged to see if that made a difference, and it didn't
Any ideas anyone, cos I'm a bit stumped
Cheers,
Ed
_Batty_ said:
AFM?
New cap, arm, leads?
New cap, arm, leads?
S13's dont have any of those
But I will check the AFm, as I have about 3 spare MrFlibbles said:
One of the many problems I had on the MRT!
Have you recently swapped the leads? Sounds strange, but I put magnecor leads on the 2, and the seal is bad on them so there was a tiny bit of water ingress, but enough to cause the intermittent misfire.
Have you recently swapped the leads? Sounds strange, but I put magnecor leads on the 2, and the seal is bad on them so there was a tiny bit of water ingress, but enough to cause the intermittent misfire.
Please say this isn't cursed like your MRT
vixpy1 said:
Where abouts in the rev range are you when it does it? Also, is it on boost?
It does it all through the rev range, boost or no boost. Its been said on SXOC it could be worn Crank Angle Sensor splines on the exhaust camshaft, so I'm going to check those tonight.
It does seem to make sense though, as if I drive mega sensibly and smoothly (anyone who has seen me drive will tell you its a rare occurance
) it drives fine with no misfiring at all, but if I'm slightly hasty with either the clutch or gas pedal, it will stutter. But keep the suggestions coming please, I want to get to the bottom of this asap
Ed
Edited by turbo-tastic on Tuesday 27th February 13:51
_Batty_ said:
whats a Gas pedal?
Its an American accelorator. It eventually gives the idiot at the wheel all the power they want without properly checking if they are mentally capable of dealing with it
_Batty_ said:
does it idle ok?
Yup, idles fine
As i said above, if driven smoothly, you'd hardly notice anything wrong at all, its only if I'm jerky with either pedal it plays up I had a similar prob on my skyline though now thanks to Thor it's gone.
1st off the plugs were changed for some copper items they had. Turned out they were shot (1.1+ gap!). This improved but still held back at 4500-5000rpm.
Next stop the coils. These were swapped for split fire items which they just happend to have to hand. That cured it, it now goes how it should and runs "cleaner" and better.
Turns out the sparks plugs had been in a long long time and the coils were the originall items-nearly 60K on them. So they were bound to have broken down over time. The copper spark plugs will be changed for some platinum items once i have done a few miles on these and got some use out of them. Hope this helps in some sort of way.
1st off the plugs were changed for some copper items they had. Turned out they were shot (1.1+ gap!
). This improved but still held back at 4500-5000rpm. Next stop the coils. These were swapped for split fire items which they just happend to have to hand. That cured it, it now goes how it should and runs "cleaner" and better.
Turns out the sparks plugs had been in a long long time and the coils were the originall items-nearly 60K on them. So they were bound to have broken down over time. The copper spark plugs will be changed for some platinum items once i have done a few miles on these and got some use out of them. Hope this helps in some sort of way.
Hi Ed, how's tricks mate, long time no speak
AFM definately sounds feasible, try giving it a clean or swapping it out, could well be a bad contact on the circuitry.
CAS sounds plausible too.
What are your plug gaps at, and which plugs are you using currently?
Fuel filter might be worth checking, but that's less likely.
All else fails i'd probably pull the fuel pump and just make sure there's no sludge in the bottom of the tank or on the pick up, I opened up the tank on my black S13 and the crap in the bottom of the tank was awful. How the fuel pump didn't grind to a halt I don't know.
Hope this helps,
Stu (Mellon)
AFM definately sounds feasible, try giving it a clean or swapping it out, could well be a bad contact on the circuitry.
CAS sounds plausible too.
What are your plug gaps at, and which plugs are you using currently?
Fuel filter might be worth checking, but that's less likely.
All else fails i'd probably pull the fuel pump and just make sure there's no sludge in the bottom of the tank or on the pick up, I opened up the tank on my black S13 and the crap in the bottom of the tank was awful. How the fuel pump didn't grind to a halt I don't know.
Hope this helps,
Stu (Mellon)
Whoops, forgot to update you 
It turned out to be the plug gaps, so give yourselves a pat on the back
Still got a slight misfire when cold, but I think that may be down to the fact that my turbo elbow is blowing until it warms up, and may be giving the lambda a false reading?? Either that or I've got the wrongs plugs, but I do havce to BCPR7ES's to go in once I gapped them (this weekend)
While I'm here I would just like to say a huuuuuugggggggeeeeee thanks to Jez Horsham of Horsham Devlopments. he reckons with the mods I have, at15psi I should be looking between 260-280bhp, but I forgot to tell him about my different inlet cam, so maybe a little more
I haven't run it as high as 15 yet anyway, but at 12psi it fecking flies
IIRC he does lots of cars there, so check it out for all your ECU chipping needs
www.h-dev.co.uk/index2.php?page=home
Stu, good to hear from you, not seen you around SXOC for a while Any reason for that, or not had the time? Hows rush junkies?? I wont be getting my wintery fix this year But will be heading down to MK SnoZone sometime over the summer.
You going to JAE or Japfest?
It turned out to be the plug gaps, so give yourselves a pat on the back
Still got a slight misfire when cold, but I think that may be down to the fact that my turbo elbow is blowing until it warms up, and may be giving the lambda a false reading?? Either that or I've got the wrongs plugs, but I do havce to BCPR7ES's to go in once I gapped them (this weekend)
While I'm here I would just like to say a huuuuuugggggggeeeeee thanks to Jez Horsham of Horsham Devlopments. he reckons with the mods I have, at15psi I should be looking between 260-280bhp, but I forgot to tell him about my different inlet cam, so maybe a little more
I haven't run it as high as 15 yet anyway, but at 12psi it fecking flies
IIRC he does lots of cars there, so check it out for all your ECU chipping needs
www.h-dev.co.uk/index2.php?page=home
Stu, good to hear from you, not seen you around SXOC for a while
Any reason for that, or not had the time? Hows rush junkies?? I wont be getting my wintery fix this year But will be heading down to MK SnoZone sometime over the summer. You going to JAE or Japfest?
Hi mate.
Glad you got her sorted
Left he sxoc a while back mate, no reason in particular, just a few things I didn't like about the place.
I'll probably drop in from time to time in the future and see what changes have been made since ken took the helm though, just haven't really thought about it as of late
Glad you got her sorted
Left he sxoc a while back mate, no reason in particular, just a few things I didn't like about the place.
I'll probably drop in from time to time in the future and see what changes have been made since ken took the helm though, just haven't really thought about it as of late
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