TheSamba.com :: View topic

Sat May 04, 2013 5:29 pm

Wanted to hear other folks' experience about this, as the shop where I had my Subaru conversion done (BusLab in Berkeley) says this is common.

I just had a Subaru conversion done on my '88 Vanagon (automatic). Drove it about 25 miles on the highway, then got to a stop light and the engine stalled. Put it in park, restarted and everything was fine. Happened two more times on my drive home later that day (again at a light, and once after accelerating after the light turned green).

Called the BusLab after the first time this happened and they said it's normal as the ECU adapts. Anyone else out there had this experience? If so, about how long did it take for the stalling to stop?

Sat May 04, 2013 5:32 pm

Did they install a VSS (Vehicle Speed Sensor)? Without it what you are experiencing is common and is not likely to go away fully, especially when coming to a stop after running at higher speeds.

Sat May 04, 2013 5:36 pm

Yes, they did install a vehicle speed sensor.

Sat May 04, 2013 6:22 pm

Is it working? The first one I installed on our van was bad and caused the same problem. 1999 2.5L out of a Forrester

Sat May 04, 2013 6:59 pm

dobryan wrote: Did they install a VSS (Vehicle Speed Sensor)? Without it what you are experiencing is common and is not likely to go away fully, especially when coming to a stop after running at higher speeds.

this is happening to me as well. not to jack your thread...I have an aftermarket ecu and, it seems nearly random, but it dies when slowing down to a stop or slower traffic. usually clutch out and it dies quietly and I don't notice as the engine is so smooth and quiet.

this issue is intermittent and could happen once in a week or 3 times in a 30 minuet drive through town.
it's maddening as it makes me question every move I make with the clutch and throttle.

usually it fires up again and runs smooth after 3-7 minuets. I don't have a speed sensor, I have an e-throttle. after it dies I can't hear the fuel pump prime when I turn the key for those 3-7 minuets...but then it kicks in and fires up

I just wonder what the speed sensor tells the ecu that the e-throttle isn't taking care of.
I'm down to buy a speed sensor if it's gonna cure this issue but RMW didn't think I needed it and the shop that's got it now trying to figure it out doesn't seem to think that's the answer.

josh is your setup fly by wire or cable pull throttle body ?

Sat May 04, 2013 7:15 pm

JPrato wrote: Is it working? The first one I installed on our van was bad and caused the same problem. 1999 2.5L out of a Forrester

Good question. Aside from stalling (which, again, the Bus Lab says is normal right after conversion), there are no other signs. It sounds like for some folks the check engine light comes on when the ECU detects abnormal voltage input from the VSS (code 33), but that's not happening for me. The Bus Lab seemed to suggest that the ECU needs to adapt and learn to interact with the VSS properly. I assumed that's what's happening, but it's entirely possible I misunderstood them. If this isn't something that's likely to go away after a few more drives, I'd definitely want to get it fixed.

Also, I just picked this up from the Bus Lab yesterday. They test drove it a few times after the conversion, though I didn't think to ask them if it stalled for them. I'm guessing it did since they warned me this might happen. I do plan to call them about this again on Monday (not open on the weekends).

Sat May 04, 2013 7:23 pm

joshr wrote: JPrato wrote: Is it working? The first one I installed on our van was bad and caused the same problem. 1999 2.5L out of a Forrester

Good question. Aside from stalling (which, again, the Bus Lab says is normal right after conversion), there are no other signs. It sounds like for some folks the check engine light comes on when the ECU detects abnormal voltage input from the VSS (code 33), but that's not happening for me. The Bus Lab seemed to suggest that the ECU needs to adapt and learn to interact with the VSS properly. I assumed that's what's happening, but it's entirely possible I misunderstood them. If this isn't something that's likely to go away after a few more drives, I'd definitely want to get it fixed.

Also, I just picked this up from the Bus Lab yesterday. They test drove it a few times after the conversion, though I didn't think to ask them if it stalled for them. I'm guessing it did since they warned me this might happen. I do plan to call them about this again on Monday (not open on the weekends).
Are you sure the CEL (or OXS lite if using stock Vanagon dash) is actually wired up for codes? Often times people don't wire this up, because there are a bunch of fuel-system based codes that are on all the time (unless you disable them with some extra circuitry) and just continually keep the CEL/OXS light turned on. I'd use an OBD-II scanner and check what codes are being thrown.

Also note that the SubaruVanagon list on Yahoo is likely the best place for these questions (although I'm hopeful of seeing more of that info here on Samba too)

Sat May 04, 2013 7:35 pm

There is a remapping period for ecu's after conversions. Give it time and drive it alot, see if it clears up. Sometimes it takes 50 or so miles for things to smooth out.

If you don't have a scangauge or maxitrip take it to your local FLAPS and have them check for codes for free.
Your obd2 plug will be wherever your ecu is.
See if it's giving a speed sensor code. P1540 I think.

It's possible your check engine light may not be illuminating but I doubt that, Buslab does great work.

Congrats on your conversion!

Sat May 04, 2013 8:53 pm

An ultragauge will give you a lot of useful information. Its also a lot cheaper then a scangauge

Sun May 05, 2013 12:25 pm

I don't have a VSS and this happens randomly on my FBW '09 2.5. Checked w/ scanner and no codes. Hope to get a VSS soon to fix it. 10,000 miles, no change.

Sun May 05, 2013 6:49 pm

what is it that the speed sensor dose that the throttle position sensor doesn't do that could fix this ?

Sun May 05, 2013 7:12 pm

Without a speed sensor telling the ECM you are moving it gets all crazy with the engine revving up and wants to close the throttle when you let it off. Hows that for a technical explanation?

Sun May 05, 2013 7:12 pm

I had this same problem when I installed a 98 EJ22 into my Syncro. I also thought it was related to VSS but it was throwing a generic code related to IAC valve.

But, the problem is caused by no neutral position switch and one of the wires needs to be grounded. I can't recall which wire/ pin number, but once I grounded that wire no more stalling. If I find some time I'll try to look through my notes to figure out which pin number it was, no promises though since I'm heading out on a month long trip in the van.

Matt

Sun May 05, 2013 7:34 pm

JPrato wrote: Without a speed sensor telling the ECM you are moving it gets all crazy with the engine revving up and wants to close the throttle when you let it off. Hows that for a technical explanation?

well...better then nothing I spose. but in my situation the engine behaves very well aside from quietly dieing sometimes as I roll to a stop or slow down...or clutch out costing down a hill.

I have an e-throttle and I assume some kind of throttle position sensor is part of it, I called RMW to buy their speed sensor kit but they didn't think it was the answer. it's all greek to me so far.

Sun May 05, 2013 7:37 pm

[/quote]well...better then nothing I spose. but in my situation the engine behaves very well aside from quietly dieing sometimes as I roll to a stop or slow down...or clutch out costing down a hill.[/quote]

I had the same symptoms as you. Ran fine until slowing down to stop.

Matt

Sun May 05, 2013 7:40 pm

Can't help you with your ethrottle. With a conventional setup the VSS definitely helps the ECU see what is happening when the throttle is closed for a prolonged period on decelerating from higher speed and keeps a little more gas going to keep it from going too lean and stalling when the clutch is pushed in. I read a thread on the samba explaining this a while back but cannot find it.......

Sun May 05, 2013 8:32 pm

hmmm, well the e-throttle is a replacement/upgrade to stock fly by wire module in more modern cars and has been included in my install.
so it may not be specifically a throttle position sensor/indicator to the ECU

but something must signal the opening and closing of my throttle...ehh whatever. the cost of a speed sensor is small potatoes to where I'm at so if it can cure my woes I'm on it.

Sun May 05, 2013 8:42 pm

What I have noticed is that when I decelerate from higher speed and have the clutch in (or in neutral) the 'idle' rpm's stay at about 800 rpm when I am above 10 mph. When I get below 10 mph, or so, it goes to a normal 650 rpm idle speed. I assume this keeps it from stalling....

Sun May 05, 2013 9:02 pm

msewalson wrote: I had this same problem when I installed a 98 EJ22 into my Syncro. I also thought it was related to VSS but it was throwing a generic code related to IAC valve.

But, the problem is caused by no neutral position switch and one of the wires needs to be grounded. I can't recall which wire/ pin number, but once I grounded that wire no more stalling. If I find some time I'll try to look through my notes to figure out which pin number it was, no promises though since I'm heading out on a month long trip in the van.

Matt

The OP does have an auto. I've definitely read about issues regarding neutral position switch, automatics, and suby conversions... BUT I thought that was related to cruise as well, and mostly an idle surge going from neutral to D.

Does the OP have stock cruise as well?

Additionally, not sure the OP mentions which Suby swap was done? EJ22 or EJ25?

Sun May 05, 2013 9:08 pm

cool...just looking now, I prefer the RMW kit over the small car unit.
cut/paste from my ecu pdf...
G4 ECU's have up to 10 Digital Inputs that can be configured for sensors/ switches such as:
Vehicle Speed Sensor
Antilag Switch
Clutch Switch (for launch control and flat shifting)
High / Low Boost Switch
Water Spray Switch
Dual Fuel / Ignition Map Switch
Nitrous Oxide Switch
Anti-theft Switch
AC Request Switch
8-[

here is a subaru/subaru swap and a similar comment in their list of issues to deal with...

1. Engine stalls coming back down to idle at stop signs. Idle is also too low. I suspect...well actually i KNOW that this is down to the neutral switch. The ECU thinks the car is in neutral full time so doesn't regulate the idle correctly.

the thread is here,,,although he doesn't specifically say if the speed sensor resolved this issue.
http://sl-i.net/FORUM/viewtopic.php?f=31&t=12871&start=0

can these speed sensors replace the normal cable ?
like if speed sensor is connected to the ECU and that is connected to this little rectangular bit next to the cable input...