infamous 5MT low idle stall - Page 4

TomsSVX · #46 08-28-2005, 11:32 PM

I only began to have this problem when I swapped my 94 motor out for a 92 with less mileage. I did check all of the vaccum lines before the install. I also used the TB from my 94 motor, so I think it is something to do with...... I have no idea

Tom

huck369 · #47 08-29-2005, 05:53 AM

Quote:

Originally Posted by rmjjensen

reviving an old thread - the last post seems to be from March of 2005.

I'm starting my conversion and who knows if I'll wind up with this problem. I'll be using an '04 WRX tranny with a stock WRX flywheel.

Everyone that has done this swap has tricked the ECU into thinking it is in N or P correct? Why not leave it to think the transmission is in the D position? I know that there is high idle involved in that trick but I'd think it would be easier to lower the idle output from the ECU rather than raise it.

The Starter won't engage if the ECU thinks the car is in drive, hence the need to trick it into thinking its in Nuetral or Park, but if you wire in the Clutch position switch, it only thinks it's in nuetral when you have the clutch depressed...., it thinks it's in drive when not on the clutch...

shotgunslade · #48 01-19-2006, 05:49 PM

Thought I would resurrect this old thread because it seems to be a problem that hasn't yet been fully resolved. Now I'm in it big as the proud new owner of a 5MT, reportedly with the stall chartacteristic. (Don't yet have personal experience with it yet, as I haven't yet picked up my car from Tom). In Tom's latest 5MT installed thread, there was a lot of discussion of the issue, before the conversation took a different turn. I got interested by the dashpot idea, and did some web-searching. Seems like stalling with carburetted engines was a pretty common problem, and dashpots were a common solution. Since I don't have my car yet, can't even look at the throttle lever and cable hook-up to see if a dashpot could be fitted in to slow the closure of the throttle when the cable is released. There seem to be dashpots available, so I guess its just a question of whether or not one can be attached in the right position.

TomsSVX · #49 01-19-2006, 05:59 PM

anything can be done Dan, even if I have to fab up a couple brackets to make it work.

Tom

shotgunslade · #50 01-19-2006, 07:01 PM

So this is what a dashpot looks like in concept

And here's one for sale at Summit Racing.

TomsSVX · #51 01-19-2006, 07:06 PM

I would have to have it in my hands and under the hood to say if I could definately do it or not

Tom

mbtoloczko · #52 01-19-2006, 07:42 PM

I've scoped it out. There's enough room to do it, and the layout is ok for it. Its just a matter of fabricating brackets.

shotgunslade · #53 01-19-2006, 08:10 PM

Summit Racing and maybe others have brackets for mounting the dashpot. It might be easier to mod them. Take a look at their catalogue.

Jade Dragon · #54 01-19-2006, 11:17 PM

To raise the idle, its easy. I did this to my 93 legacy. unscrew your TPS and adjust it up/down until you find the idle you want. the ecu thinks its getting the correct data, so it wont adjust it down

shotgunslade · #55 01-20-2006, 06:02 AM

The dashpot doesn't really raise the idle speed. It basically acts as a cushion to give the throttle actuator lever a soft landing when it is abruptly released by lifting off the accelerator. The throttle closes normally and the idle is at normal speed after a brief delay. This delay avoids stalling the engine.

longassname · #56 01-21-2006, 11:07 AM

The dashpot sounds like a good idea. Are any of you working on that? Just for my own information/curiosity does anybody with a manual transmission from a non turbo car have the stall problem? It seems to me if everyone who has the pull type throw out bearing has the stall problem and nobody who has the push type throw out bearing does that that is good information to know. When our understanding and the facts don't mesh it's our understanding that needs to change.

TomsSVX · #57 01-21-2006, 11:17 AM

My Sti 6 speed doesn't stall. And my old 4.115mt from an N/A imprezza did. it is more reliant on the engine than anything else. When I blew my 94's motor, I swapped in a 92 engine. Then it started to stall. Take that for what you will

Tom

longassname · #58 01-21-2006, 11:26 AM

got ya. well you are around a lot of manual conversions do you think the stall problem is more common with the pull type clutch or is it a completely irrelevant coincidence that so many of the people with the stall problem have the wrx tranny?

So anybody tried the dash pot yet? It seems to me if it's air then the dashpot will fix it. If it's fuel then I'll fix it. I'm going to change the minimum pulsewidth in stage 2v6.

SVXRide · #59 01-21-2006, 11:29 AM

Quote:

Originally Posted by longassname

got ya. well you are around a lot of manual conversions do you think the stall problem is more common with the pull type clutch or is it a completely irrelevant coincidence that so many of the people with the stall problem have the wrx tranny?

So anybody tried the dash pot yet? It seems to me if it's air then the dashpot will fix it. If it's fuel then I'll fix it. I'm going to change the minimum pulsewidth in stage 2v6.

Michael,
Any feel for when you'll have the 2v6 chip available?
-Bill (currently planning on installing his 2v5 chip today...)

TomsSVX · #60 01-21-2006, 11:38 AM

I feel the ECU is to blame. It is not setup for a Manual trans so when the engine is on decel, there is next to no rotational mass attached so it drops too fast for the IAC to compensate for. If you could fix it to speed up the IAC's reaction I feel the problem would be solved

Tom