Very Cold:Stuttering, Very Hot: Stalling. Related or coincidence?
#1
Very Cold:Stuttering, Very Hot: Stalling. Related or coincidence?
So I got this 5-speed boosted tC with a bunch of work done to it, slowly getting it more usable/ideal driving and am trying to sort out the one last running/driving "bug" the car has.
So as long as I've been driving it, when the car is very cold (as in, the first time driving it all day, or it's been sitting for like 8 hours at work), it will stutter a bit at low rpms under normal non-boosted acceleration. I'm running an AEM FIC, and it does this with/without the resistor mod. It always goes away after the car warms up a couple minutes, so I've never paid much attention to it.
What did get me thinking is this "new" issue (which MIGHT be related). Now that I've had my first full summer driving the car (last year I drove it in like October, so it was already cooling down a lot up here), if I'm driving the car for quite a while (say 45 mins on the highway or something) and if it's a really hot/humid day, the car has a small chance to stall when I clutch in to slow down. It only happens MAYBE once or twice a day (if even), when I'm doing lots of driving and when it's pretty hot outside, and the car always starts up fine again (or if I put it back in gear quickly it'll get going again, but I know that's not really the best idea) and drives fine after. I've tried keeping an eye on my AFR but that seems fine too.
My only thought has to do with a "previous" issue with the car. I'm running BC stage 2 cams, and having talked to paul dezod on this site, found that those cams were giving me problems with starting up (Cam Position Sensor couldn't get a good read on the cams when they were hot). That site now mentions to adjust the dowel pin so it doesn't happen to future cars, but what I was able to do was modify my CPS by trimming down the inside of the plastic housing such that the sensor sits farther into the engine. It fixed the startup problem (now always starts, never backfires when cranking), but I'm wondering if maybe that's somehow related to this now hot-stalling issue?
I've tried researching, but haven't found much of use. I've cleaned my MAF a couple months ago (haven't gotten around to throttle body), and I DO have a CEL, but don't have the tools/locations to get it checked (trying to find a place up here in Canada that'll let me scan my codes). I've heard that with more aggressive cams and injectors (880cc), issues like this might pop due to the ecu/fic combo not being able to adjust fast enough, but the only piece of advice I have found is potentially an O2 sensor problem, but it's noted to be unlikely the cause of stalling. I haven't been able to find anyone else with this problem, so hopefully someone has some thoughts on the matter?
So as long as I've been driving it, when the car is very cold (as in, the first time driving it all day, or it's been sitting for like 8 hours at work), it will stutter a bit at low rpms under normal non-boosted acceleration. I'm running an AEM FIC, and it does this with/without the resistor mod. It always goes away after the car warms up a couple minutes, so I've never paid much attention to it.
What did get me thinking is this "new" issue (which MIGHT be related). Now that I've had my first full summer driving the car (last year I drove it in like October, so it was already cooling down a lot up here), if I'm driving the car for quite a while (say 45 mins on the highway or something) and if it's a really hot/humid day, the car has a small chance to stall when I clutch in to slow down. It only happens MAYBE once or twice a day (if even), when I'm doing lots of driving and when it's pretty hot outside, and the car always starts up fine again (or if I put it back in gear quickly it'll get going again, but I know that's not really the best idea) and drives fine after. I've tried keeping an eye on my AFR but that seems fine too.
My only thought has to do with a "previous" issue with the car. I'm running BC stage 2 cams, and having talked to paul dezod on this site, found that those cams were giving me problems with starting up (Cam Position Sensor couldn't get a good read on the cams when they were hot). That site now mentions to adjust the dowel pin so it doesn't happen to future cars, but what I was able to do was modify my CPS by trimming down the inside of the plastic housing such that the sensor sits farther into the engine. It fixed the startup problem (now always starts, never backfires when cranking), but I'm wondering if maybe that's somehow related to this now hot-stalling issue?
I've tried researching, but haven't found much of use. I've cleaned my MAF a couple months ago (haven't gotten around to throttle body), and I DO have a CEL, but don't have the tools/locations to get it checked (trying to find a place up here in Canada that'll let me scan my codes). I've heard that with more aggressive cams and injectors (880cc), issues like this might pop due to the ecu/fic combo not being able to adjust fast enough, but the only piece of advice I have found is potentially an O2 sensor problem, but it's noted to be unlikely the cause of stalling. I haven't been able to find anyone else with this problem, so hopefully someone has some thoughts on the matter?
#2
So as long as I've been driving it, when the car is very cold (as in, the first time driving it all day, or it's been sitting for like 8 hours at work), it will stutter a bit at low rpms under normal non-boosted acceleration. I'm running an AEM FIC, and it does this with/without the resistor mod. It always goes away after the car warms up a couple minutes, so I've never paid much attention to it.
I haven't been able to find anyone else with this problem, so hopefully someone has some thoughts on the matter?
#5
Based on this we had done a few changes to my maps (at the time you didn't know about my cam thing), I'm wondering if maybe those changes then negatively affected this new issue, and maybe those old "bad" maps were actually fine (now that I got the startup issue sorted out with the sensor)? Maybe I'll try going back to those old maps (when I got my car tuned in spring) when I get a chance, worth a try at least.
#6
This is the most interesting part. Not sure if you remember helping me last time with that startup issue I had wherein:
Based on this we had done a few changes to my maps (at the time you didn't know about my cam thing), I'm wondering if maybe those changes then negatively affected this new issue, and maybe those old "bad" maps were actually fine (now that I got the startup issue sorted out with the sensor)? Maybe I'll try going back to those old maps (when I got my car tuned in spring) when I get a chance, worth a try at least.
Based on this we had done a few changes to my maps (at the time you didn't know about my cam thing), I'm wondering if maybe those changes then negatively affected this new issue, and maybe those old "bad" maps were actually fine (now that I got the startup issue sorted out with the sensor)? Maybe I'll try going back to those old maps (when I got my car tuned in spring) when I get a chance, worth a try at least.
#7
Ah alright, worth a try due to the fact that it'll only take me a few minutes to do.
Any thoughts on the stalling issue? The only other thing I was going to mention with that is that sort of what I mentioned above, when the car revs down when clutching in during deceleration, it almost feels like it doesn't react fast/early enough then the revs drop down too low (say about 400) then it just gives up entirely and stalls. But it also feels as though the revs are dropping faster than they do when it's normally revving down.
Any thoughts on the stalling issue? The only other thing I was going to mention with that is that sort of what I mentioned above, when the car revs down when clutching in during deceleration, it almost feels like it doesn't react fast/early enough then the revs drop down too low (say about 400) then it just gives up entirely and stalls. But it also feels as though the revs are dropping faster than they do when it's normally revving down.
#8
Ah alright, worth a try due to the fact that it'll only take me a few minutes to do.
Any thoughts on the stalling issue? The only other thing I was going to mention with that is that sort of what I mentioned above, when the car revs down when clutching in during deceleration, it almost feels like it doesn't react fast/early enough then the revs drop down too low (say about 400) then it just gives up entirely and stalls. But it also feels as though the revs are dropping faster than they do when it's normally revving down.
Any thoughts on the stalling issue? The only other thing I was going to mention with that is that sort of what I mentioned above, when the car revs down when clutching in during deceleration, it almost feels like it doesn't react fast/early enough then the revs drop down too low (say about 400) then it just gives up entirely and stalls. But it also feels as though the revs are dropping faster than they do when it's normally revving down.
#10
#11
Being in gear and engine braking/downshifting does in fact promote ENGINE piston ring sealing to the cylinder walls: true.
Fuel delivery and trajectory is very different on the second half of the tank than the first. This is why I always suggest never running below half a tank on a turbo tC.
Wish I got a $1 every time I was misquoted.
Fuel delivery and trajectory is very different on the second half of the tank than the first. This is why I always suggest never running below half a tank on a turbo tC.
Wish I got a $1 every time I was misquoted.
#12
Being in gear and engine braking/downshifting does in fact promote ENGINE piston ring sealing to the cylinder walls: true.
Fuel delivery and trajectory is very different on the second half of the tank than the first. This is why I always suggest never running below half a tank on a turbo tC.
Wish I got a $1 every time I was misquoted.
Fuel delivery and trajectory is very different on the second half of the tank than the first. This is why I always suggest never running below half a tank on a turbo tC.
Wish I got a $1 every time I was misquoted.
Thread
Thread Starter
Forum
Replies
Last Post