Installed MarkD chip. Car won't turn over.

[rumatt]

So I installed my 93 octane, MarkD chip in my 90 325is.

There's power to the car, and the fuses look good, but when I turn the key, nothing happens. Any ideas?

I guess I'm going to put the old chip back in, and make sure that one still works, but is this a sign of a common mistake? Defective chip??? It's for a 173 ECU, and my ECU had 173 on the outside of the box.

[Il Duce]

make sure you push the chip all the way down, sometimes it will even go "click" its a stupid thing to do, but i did it. lol. good luck

[rumatt]

Fuck. I put the old one back and it still won't start. Maybe I didn't push that one in far enough either. I'll try that. (praying)

Thanks.

[rumatt]

No luck. Man, am I pissed.

I was super careful not to have any static electricity. Now what???

[rumatt]

When I turn on the ignition, I can hear a slight buzzing from the ECU. It's got to be fried????

[Mike 91 318ic]

Is the chip in backwards? make sure you connected the ecu securely

M

[rumatt]

Is the chip in backwards? make sure you connected the ecu securely

I made sure the notch on the chip was lined up with the notch on the base. The writing on the chip lined up in the same direction as the original one before it was removed. The batter was disconnected when all work was done.

[Mike 91 318ic]

sounds like the chip is installed the right way, what about the ecu connection? other than that I have no idea what the problem could be.

M

[rumatt]

what about the ecu connection?

Yeah, I connected it and reconnected several times.

There is a definite buzzing from the ECU when the ignition is on (just one click, not when I'm trying to start the car), and the behavior is the same regardless of which chip is in the ECU. I can only assume the ECU is toast. Could a bad chip have done this?

I was going to bring the E30 to its first autox tomorrow too. I'm such a moron.

[MarkD]

Fuck. I put the old one back and it still won't start. Maybe I didn't push that one in far enough either. I'll try that. (praying)

Thanks.

One possibility is that you scratched a trace (copper wire) on the printed circuit bpard (PCB). Did you use a screwdriver to remove the OEM chip? Check that you have not scratched a trace. It's very hard to fry an ECU, and killing it due to static is also hard to do. An ECU will always start if it was damaged by static, it will have problems that are intermittent.

Are you absolutely sure you had the chips in the correct way? If you put them in backwards, there is a high probablility that you killed the EPROM chip.

MarkD

[rumatt]

One possibility is that you scratched a trace (copper wire) on the printed circuit bpard (PCB). Did you use a screwdriver to remove the OEM chip? Check that you have not scratched a trace. It's very hard to fry an ECU, and killing it due to static is also hard to do. An ECU will always start if it was damaged by static, it will have problems that are intermittent.

Mark, thanks for offering help. I did use a screw driver, but I was ridiculously careful. I'm sure I didn't scratch anything.

Are you absolutely sure you had the chips in the correct way? If you put them in backwards, there is a high probablility that you killed the EPROM chip.

I'm 100% sure that I had the notch on the chip lined up with the notch on the base. I checked it 3 times.

What about the buzzing I hear in the ECU? Has anyone experienced this, and is it a sign of ECU death?

[rumatt]

WOOT! It works.

There was a wire in my fuse box that was disconnected. (not a fuse, an extra wire that I will post a picture of soon). It has been like that for a week now, after it poped out while I was replacing fuses. The car worked fine, so I left it as is.

On the off chance that it would make a difference, I plugged it back in and the car started. WTF? I'll post a pic later.

Thanks for all the help.

[rumatt]

Sorry for the delayed update. I was out autoxing today.

It looks like it had nothing to do with the MarkD chip. (and thanks for emailing me to offer help Mark. :up: )

I don't have a place to host pics, but if you have access to bimmerforms you can see this wire in my fuse box in this post: http://forums.bimmerforums.com/forum...p;postcount=11

I think it's an aftermarket alarm. The wire was unplugged for several days with no problem so it's not needed for starting the car normally. But once I disconnected the battery it was necessary.

[RCWells]

So how does it run now with the new chip??

[rumatt]

Runs great !

My butt dyno isn't very accurate, so it's hard for me to say exactly how much gain there is. Plus, I haven't had the car all that long. But it definitely felt faster.