Hesitation Found: Ecu Crush Mod Really Works
 

I had some spare time tonight wile waiting for the paint on my wiper arms to dry, so I got on the Mitchell and looked up TSB's on hesitation and there it was right on the screen, I couldn't belive it. I had always thought the ECU crush mod was a hack fix, I didn't know it was an acctual factory TSB. So I had the directions and a nice pic of where it was, so I pulled out the ECU and crushed that baby, and on the way home NO MORE FREAKIN HESITATION! Happy Day.



Also disconecting the battery seems to have reset my idle problem after adjusting my TPS. Happy Day indeed.

wow, i guess i should check into this....do you have the tsb handy?
thanks
phil

That all sounds kewl. But were do i look up for those for my SVX? and how to do it.

thanks man., I would love to kill that hesitation., well ttyl

Check the how-to locker and yahoo locker/archives for the TSB and how to on the crush mod. It's there. But I don't have a 92 so I don't have to do that. :)

thanks....
 

think Ill do mine this weekend and take some pics
of the process if I remember my camera.....
This stuff all over the web, just got to search ;)

Heres a good link
 

for some good pics and info

http://www.scoobymods.com/forums/sho...s=&threadid=98

Now I do have one Q before i do end up crushing something in my newly purchaced svx hehe,

Does anyone know if this has any long term effects on the car?

thanks ttyl

Is this somthing everyone can benefit from? I don't have any noticeable hesitation on my 92 or maybe i do and i'm just so used to it i don't notice it. Any help you can give me subafreak and i'm sure Type O would be proud.

if its a TSB directly from Subaru....
you can usually trust it. An engineer made this happen
not some kid in ohio who thought it may be a good idea.
If you have a 92, it cant hurt to do it regardless

If you have a 92, it can't hurt.

I'm more than ready to do this, but I'm not sure I understand the issue of Hesitation?
When, where does this occur?
I know the car definately hesitates when its cold, but is there something a little more specific?

I suppose I could just crush the bugger and see....:p

Hesitation ?
 

Yes please, will someone define the hesitation referred to. Is this the rather tardy kick-down response which is annoying when one calls for everything on tap when making an overtaking manoeuvre ? If so an improvement would be welcome.

The component involved in Òthe crushÓ is most certainly not a resistor and is more certain to be a ferrite bead inserted to prevent possible R.F. interference, hence the reference to noise suppression. Just how removing it could cure Òhesitation Ô is rather intriguing and must have presented a curly problem to the original designer.

standard hesitation
 

From a dead stop, when you take off
many 92 cars experience a hesitation
for a split second before the car actually
takes off.......
Sometimes the hesitation is also caused by
transmission woes when the cars cold
but thats a whole different ballgame.....

Trevor, I think its actually an inductor or coil(can't remember what they are called, but opposite of a capacitor), and we can't remove it, we just crush it a little, which I would expect reduces its inductive charactoristics therefore changing some logic decision.
Capacitance/inductance.

Anyways, I'll give it a shot, and see where it changes the so called hesitation, maybe everywhere???

yeah, its a wire that we merely are removng the resistance from. Who knows why it is there to begin with :)
phil

Yes it's acctually a noise suppresor, and your doing is crushing the suppresion stuff to make it crumble apart and fall off the wire. As the directions say "don't break the wire, or you will have to replace the ECM". The TSB states that if a customer comes in with a complaint of hesitation that it's a normal thing and it's just the ECM doiing it's thing, but if the costomer isn't happy with that answer to do the crush mod. Now I think I always had the hesitation but with the auto it seemed like more of a tranny thing, after I did the 5 speed swap the hesitation became a noticable and annoying engine thing. I belive the crush mod is a must for anyone with a 5 speed and that it can't hurt for anyone with an auto either. Just Do It.




P.S. Shot King, I think you might be the first person here to have any idea where I got that from.

Thanks S-Freak, thats what I wanted to here.
Everybody has an opinion, but just tell me to do it. And I'll listen.:D

HELP HELP HELP!
 

I just got the ECU off and I have no clue which of the damn resistors I need to cut! Here is what it looks like:

http://www.subaru-svx.net/photos/files/tuzem/11342.jpg

Somebody, please help ;) Thanks!!!!

-Nick

Pics in my locker of the ECU location and internals - some may not have the bead in there to crush. This is a great mod - one of the first I did on mine shortly after buying it.

Hmm... I don't have the tan and the other resistor... Does this mean I don't have the hesitation problem? Or just that I can't do anything about it??? Thanks!!!

Nick

My wifes 92 did not have them either - see the pic in my locker. But her's did have a chip in the slot where mine was empty. Her svx was manufactured 6/91 and it does not hesitate a bit - looks identical to the ECU you have in your locker.

Cool :) Thanks! Mine was also made 06/91 and has the chip. I guess I'll put it all back together ;)) Thanks!

-Nick

Crap, I just pulled my ECU, and opened it, and I have the Bead-less model, but with the tan resistor cut. So I guess thats why I don't feel the hesitation. see my locker.
BTW, I looked in the ECU before reading the above 2 posts, and wet myself, thinking some-one cut the tan resistor by mistake. But its apparently normal. Good to know.

Oh Well, no bead crush mod for me.:rolleyes:

Hmm' mines a 5/91 and had the noise supressor and had the chip with no tan resistor. Another interesting thing on the TSB is that it says if you have the chip the tan resistor should be cut. It seems like the chip would be important and should be in every ECU. I wonder why they made so many variations of the same ECU? It also says that if there is a black dot next to the part # on the ECU that it won't have the noise supressor so don't bother opening it. Maybe I should have mentioned that earlier.

Its ok, I would have stopped if I saw your first Post.

I may have to investigate this for my SVX. It has a hesitation just off idle when accelerating from a stop. I doubt the mod has been done to it yet. I hope it works for me. :)

I did it to both my cars(92s). On the black one, it made a huge difference. On my yellow one, it made no difference. Both ECUs were the same model #, the rarest of the bunch. So results may vary.

Stephen

I posted a How-To last night in the Documents on how to do this. :)

Good job on the how-to, Earl. Pretty soon we'll have our own version of the service manual with all the how-to documents that have been written! :D

Now I am trying to put them into folders so it will be easier to get to the ones you want. :)

question
 

Which chip are you referring to ? can you circle it and post
a pic?
So far Ive seen ECUs with:

1 ECU w/ tan resistor (some cut, some not yet)
(whats cutting this wire suppose to do?)

1 ECU w/ tan and black resistor (with the black one crushed)
just leaving the tan one intact AND not cut...
(I know this should help with the hesitation)

1 ECU with no resistors and a chip in some ROM location
which shouldnt be touched.

Also, so this message:
"... clear the memory using the select monitor."
Hows this done ?

thanks...DG

Here's the pic with the chip circled
http://www.subaru-svx.net/photos/fil...suby/11479.jpg

Whats the Chip do?
Or whats it for?
looks like an old fashion Eprom, the kind anyone can read and write to?
Is this where the Region Mapping is done?
Mapping of Altitude compensation, fuel Mixture, etc?

There is a How-To in the locker with pictures. :)

Thx Earl. But I'm still lost. (As usual)
Can you help me narrow down which How-To I should look at for the ECU Chip details?:confused:

seriously dude, who knows who cares...
some engineer for Subaru knows what its for and why
its there. Thats not the type of info thats commonly
found out by joe shmoes like us. All I care is that its there for a reason and the cars price tag didnt jump up because of it. :):D

Gee Chris, you are gonna' miss out! We are having an engineer come and lecture our group at the next meet (Drive and campout). They will take it apart and put it back together for us and let you touch it and everything! :rolleyes: ;) :D jk

I don't think the how to details the chip itself, it only shows it. The name of it is "ECU Mod (Noise Suppressor Bead Crush)" That's all there is. :)

Thanks Earl, :rolleyes:
Give the Guest Engineer my best:cool:
Oh, and finish writing that How To on Owning 5 SVX's:p

:D :D :D

The local subie tech told me the chip would show a noticeable increase in performance on my svx. He said all he needed was my vin to order one for me. I was concerned about it adding a speed limiter or something so I did not do it on mine.
I have, however, swapped ecu's between my car and my wife's car (her's is chipped, mine is noise suppressor crushed with no chip) and saw no difference in either car's performance. I did not test the top speed though.