It Won't Go!

[ianm003]

Does anyone have any suggestions, I've just fitted a new battery to my '98 1100GS and whilst I was waiting for delivery of the battery I refitted the original exhaust and what I am told by the previous keeper was the original ECU Chip. Not sure of the origin of the chip I took out but it looked like someone had been trying to solder across a couple of the legs. The bike had been giving poor fuel economy hence the reason why I wanted to go back to standard. Put it all together earlier, turned on the ignition blipped the throttle fully open three times as I'd read to do so on other threads to set the Motronic. When I pressed the start button plenty of oomph from the battery everything seemed to turnover ok but the bike would not fire. I then noticed petrol was seeping through the join between the headers and the exhaust. Any ideas before I start ripping it all apart again to check that I have put the chip in without damaging any of the legs.

 

[Steptoe]

I'll start with the simplest and obvious question-

check your throttle cables are fully seated in the throttle bodies - they have a habit of becoming dislodged whenever the tank is removed or lifted. And the bike doesn't start or struggles to run.

 

[ianm003]

Yep, these are in place as they should be fell foul of this one before.
Cheers

 

[Roger Chatterton]

If someone has been soldering across contacts on a IC Chip, then highly possible that the static might have blown the chip. Those IC's can be very very sensitive to static, let alone trying to solder them.
However, some IC's are more prone to this than others, so might be a false trail...just thought I'd mention it !!

 

[ianm003]

Still won't go, this morning I put the previous chip back in the motronic that was working prior to having the battery out for a week, went through all the reset etc, check the throttle cables were seated properly, heard the fuel pump turn over as normal when I turned the key and checked all around the area under the tank where I might have dislodged anything. Everything seemed fine. Having done some more reading on here I guess that neither of the chips that I've got are genuine BMW as they both are the same size and sit piggy back on an adapter board rather than plug directly into the Motronics board. Now the only other thought I've had is that I may have reinstalled the adapter the wrong way round whilst concentrating on making sure that the chip is put back the right way up. Anyway net result bike turns over fuel is getting through but still will not start?
HEEEEEEEEEEEEEELP!

 

[Womble]

I would urge extreme caution at this point!

Your best plan of action is to attempt to return the bike to its last working state, which would be with the chip that you took out, and with the adapter in place. Getting the adapter the wrong way round may not have fried the chip, but then again, if the adapter is currently the right way round and you swap it, you could fry the chip after all. Right now, don't swap anything around, but be extremely careful to pay attention to which way round everything goes. Label or photograph everything so there is no chance of any further confusion.

There is little more advice that is likely to be possible without providing some decent photos.

Before you do anything, think about anti-static precautions. If you can, keep the chips on/in an anti-static bag (the silvery ones that you get hard drives in are good) as you are working. Never pick chips up by the pins, always by the ends. Before you pick up a chip, always touch the packaging or earth for the board that you're working on. As Roger said, failure to watch out for static is a great way to fry chips. Before the moaners have a whinge, you may well get away without doing this, but you will have a chip that will fail prematurely and in unexplained ways - here and now, it's all about damage limitation!

Could you please get the best quality photos that you can of:

• Both chips (let us know which is which)
• Both sides of the adapter
• The area that the chip plugs into on the ECU

When photographing the chips, it would really help if we can read the markings.

I'm not promising anything, but I'll see what I can do!

Edit: You'll need to be a subscriber to post pictures, and there is a great guide here about posting photos

 

[ianm003]

Thanks for the advice I'm gonna be stuck now for the next few days due to work commitments but I'll try and sort some photos in a few days.

 

[Mac]

Nice one Tobemory......

I'll smoke you a kipper..........

 

[Bastille]

I guess you have checked to see that the kill switch hasn't been flicked by accident! I know it sounds simple but the answer often is and we miss this as so obvious.

 

[ianm003]

Took a while but sourced a secondhand Motronic unit plugged it in and the bike started, so when I opened up the original unit and changed the chips back and forward must have caused some damage. Very Happy now though.

 

[Womble]

Glad you got it sorted.

Don't ditch the old unit - it's unlikely that you've killed the rest of the circuitry, just the chips. If you can get a replacement chip, the unit should be fine.