Crazy choking power loss after shifting under hard acceleration?

Re: Re: Crazy choking power loss after shifting under hard acceleration?

BremertonMSP said:
Here you say you are peaking at .70 but later on you say you are running 9psi? I'm a bit confussed at what you are saying.

So this is an intermittant problem that only occurs after hard boost and then when you get on it hard again right? But that is only "after" you where able to get on it hard once, like to 9 psi.

flat_black may be on to something with his idea with the VTCS.

lol

my bad there: I peaked today at .7, but it usually rests back around .65 or so - so I guess its more like 9.5.
 
VTCS is only for swirling the intake air under 130F and below 3000rpm when the car is warming up. This has nothing to do with that. VICS is activated at 4750rpm and remains active until RPMS drop below 4500rpm.

What is occuring is a lot of fuel trying to get ignited at the wrong point in time. It's a problem inherent with our ECU mapping.
 
i hit fuel cut in 4th last night
i had my JoeP set to 9psi
it spiked to like 10
usually MSP's hit fuel cut arround 9.99

was it cold where u were?
cause i hit fuel cut when it was really cold outside.

it happened right after i shifted, just like it happened to u.
but i didnt try to repeat it, i just pulled over and brought the MBC down to arround 8.5........hasnt done it since.

what do u think Heathen and Turboge, could he have experienced fuel cut?
 
Flow cut is a whole nother animal, it feels different than the rich condition caused from excess fuel when air isn't abundant and sparks aren't that powerful.
 
The first time it happened to me, I was pulling onto the freeway in third, at the end of the ramp I shifted to fourth and gave it about 3/4 throttle. The car seemed like it shut off for a split second and then bucked violently. There was a 2nd gen eclipse gsx behind me and was probably thinkin WTF?!?! I pulled over to check everything and all looked normal. I took it easy the rest of the way home, and adjusted my BOV when I got there. It has done it again under similar circumstances since, but never that violently, I was really worried at first, did not feel good for the car at all.
 
Dr.Sound said:

was it cold where u were?
cause i hit fuel cut when it was really cold outside.
would that be california cold(65)
or midwest cold?(12):D
 
Emode said:
would that be california cold(65)
or midwest cold?(12):D
^ lol
it was like high 40's that night.....pretty damn cold (at least for Cali)
 
i should say so
when i was in LA a couple years ago, i was sketing around at like 11pm and met a bunch of other skateboarders
it was january at the time and it was like 60 in LA, so i was wearing shorts and a tshirt, thinking it was paradise, and all these other guys are freaking out wearing like sweatshirts and s***. Goodtimes had by all.[/threadjack]
 
dr. sound said that if u have the stock plastic pipes, the kind of stuttering u feel and power choke is caused by the pipes flexing. that's what happens to me whenever i drive for over 30 minutes or so and if it's a lil' warm outside. then again if u have the iON pipes and chiller, it could be a bad seal...the engine causes so much flex that it could potentially moving the pipes around to cause a small leak while @ WOT
 
Not a bad idea, but I think that is doubtful, just because I have tightened the connectors down a lot and I check them frequently. Unless the IC core itself has a leak, which is also highly doubtful. Also, it doesn't happen all the time, which after the hesitation problem and seeing how inconsistent that was, makes me have to agree with turboge that the stock PCM is just not right. It seems like a fuel/airflow related problem for sure.
 
the expansion of plastic pipes will not couse loss of power
just a little jerk

some can say "hesitation" of a sort
 
Its not the plastic pipes guys. It the rich mixture thats all. I find that if I disable VICS my car becomes very smooth on and off gas and doesn't buck at all when letting off of gas right around 4k rpm where the bucking is at its worst me. You do loose a bit of power under 4k rpm, but I'll take that trade off any day for a smooth car. I do a lot of driving in traffic and the smoothness on and off of gas is very important to me. Now if we had stronger motor mounts all of that would change for me.
 
Dr.Sound said:
i hit fuel cut in 4th last night
i had my JoeP set to 9psi
it spiked to like 10
usually MSP's hit fuel cut arround 9.99

was it cold where u were?
cause i hit fuel cut when it was really cold outside.

it happened right after i shifted, just like it happened to u.
but i didnt try to repeat it, i just pulled over and brought the MBC down to arround 8.5........hasnt done it since.

what do u think Heathen and Turboge, could he have experienced fuel cut?

The fuel cut, which I'm familiar with, is an entirely different beast. It's a slam (hitting a wall) when fuel cut hits whereas this is more like an undulation in power delivery. If chwood was experiencing what I was, which I can't speak for him, this is a feeling of power deliver bouncing around even with the pedal held at a steady amount of pressure, very different from both the hesitation and fuel cut. If he is experiencing fuel cut it should be cut and dry...a feeling of complete power loss for a brief moment then power resuming.

chwood, is are you hitting a wall or is it more of a variance under steady throttle?
 
Man something is up with these cars because now heathen is describing what my car was like pre flash. Hold your foot steady on the gas more than 3/4 throttle, and instead of it maintaining speed or gathering speed, it feels like a pulsing on/off/on/off. WTF is going on???
 
CustomMSP said:
Its not the plastic pipes guys. It the rich mixture thats all. I find that if I disable VICS my car becomes very smooth on and off gas and doesn't buck at all when letting off of gas right around 4k rpm where the bucking is at its worst me. You do loose a bit of power under 4k rpm, but I'll take that trade off any day for a smooth car. I do a lot of driving in traffic and the smoothness on and off of gas is very important to me. Now if we had stronger motor mounts all of that would change for me.

So how would a guy go about disabling VICS? Because I'm with you on hating the jerky start/stop.

On the other hand, would something like Spool's E-Manange fix this also?
 
505zoom said:
Man something is up with these cars because now heathen is describing what my car was like pre flash. Hold your foot steady on the gas more than 3/4 throttle, and instead of it maintaining speed or slowly gathering speed, it feels like a pulsing on/off/on/off. WTF is going on???

well, mine was most noticeable at slower speeds. Similar to the crazy jerky ness our car has at parking lot speeds if you give unsteady throttle. I blame it on rushed design a.k.a. characteristics of the car :bs: btw, I do have the flash.
 
Heathen23 said:
The fuel cut, which I'm familiar with, is an entirely different beast. It's a slam (hitting a wall) when fuel cut hits whereas this is more like an undulation in power delivery. If chwood was experiencing what I was, which I can't speak for him, this is a feeling of power deliver bouncing around even with the pedal held at a steady amount of pressure, very different from both the hesitation and fuel cut. If he is experiencing fuel cut it should be cut and dry...a feeling of complete power loss for a brief moment then power resuming.

chwood, is are you hitting a wall or is it more of a variance under steady throttle?

now this is more what i would have described as the pre flash stumbling, as opposed to the hesitation, which were both products of the bad maps. There was (at least in my understanding) two distinctly differnt issues, the hesitation being more involved with full throttle acceleration, and the stumble being more involved with partial throttle boost transition into vacuum. I think these issues still are apparent once in awhile even while running the flashed ecu.
 
Im sure with stand alone management youll be able to correct a lot of the issues that go hand in hand with a rich a/f mixture, like the jerkyness with our car. To disable VICS(Variable Intake Control System) unplug the WHITE male connector that sits on top of the intake manifold. If you unplug while youre on the passenger side you'll see the shaft on the actuator move the butterflies open in the manifold. The GREEN plug is for VTCS which will throw a CEL if unpluged. The VICS plug unpluged does not throw any CELs as far as I know. I dont know what problems unplugging the VICS might lead to in the long run so do at your own risk please. I dought that this would cause any problems though. The butterflies will get stuck in the "open" position if left unplugged for a while(6 months or more). That's not a problem because all one will have to do is move the shaft around for a bit to get the butterflies moving again. Have fun and be safe. :)
 
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