Van

I made a short video while I opened up a spare DME. I thought it might be helpful to anyone looking to upgrade chips or looking for cracked solder joints.

bonus12

This should help so many people. Long overdue...Van, your videos will last on and on. Million Thanks.

fred27

Very helpful, thank you for this.

ried

Very helpful! I wish this had existed about four months ago when I chipped my S2. Would have saved me a ton of time.

Grandpa#3

Van, as usual you have made another top notch video that was much needed to help us understand how to get the DME / ECU apart and what to look for.

Thank you,
Larry

odurandina

Van is a righteous dude.

Dash01

Van, thanks very much for sharing this with us.

Could you please elaborate on the fuel quality switch, and how it may be adjusted for optimum power and fuel economy?

Two other things:

A common fault in these units is the ignition trigger, the round silver thingy on the left side of the board near your left thumb at 6:37 into the video. This can be cheaply replaced for about $5 from an electronics supply house. Its solder joints are common faults due to hairline cracks from thermal cycles. I've read that when the DME fails, it's often just the ignition trigger, an easy DIY fix. I keep a spare DME with new trigger in my glove box.

Chip notch: BEFORE removing the chip, note which way the notch faces. Be advised, however, that in my case that particular eBay aftermarket chip had a notch that faced the other direction, so when installed, the car would crank but not start. I was afraid to reverse it, lest I damage the engine or computer. Finally, I bit the bullet and reversed the chip, the car started right up and ran fine with no ill effects. Be cautioned, however, your results may not be the same, so note the notch orientation BEFORE removing the original.

A $5 soldering pen or 5 in 1 hobby kit (wood burning pen with selection of fine points and blades, HF item no. 38593) from Harbor Freight has fine tips that make an excellent tool for reflowing small solder joints without messing up nearby points. Wear good glasses and/or use a magnifying lens to see what you're doing, as cross-flowing solder joints is a risk here. It may be best to heat the tip of one connection, then let the heat flow from that tip to heat and reflow its solder, rather than just touching the solder, which can get sloppy. Soldering experts, please chime in here and correct any misinformation.

Also, crud and corrosion gets into the various connections and sockets between chips and board, ribbon tape, etc. GENTLY prying them apart after noting how they fit, and a quick spray of electronic contact cleaner ($3/can at Walmart) does a nice job of assuring good electronic contact.

It may be worthwhile to consider warming the open unit in the oven for an hour at ~180 degrees to get any moisture out, spritz with WD40 moisture repellent before closing the box, and/or sealing the box with aluminum foil tape. Electronic experts please chime in here and correct any bad info from me.

crooster

Van - thanks for taking the time to post these videos. I have found them very useful.

Van

Well, for max power, you'll need to do tests on a dyno in each position... but, generally, I've found the position 3 (+6% fuel) yields an extra HP or 2.

I suppose, for max fuel economy, you'd want position 6, which reduces the fuel and retards the timing.

For more on the FQS and its settings, look here: http://www.motronic.ws/fqs.htm


There is a printed mark under the socket which should help you figure out which side of the socket the notch goes. Interesting about your chip with the backwards notch!

p.s. do you have a p/n for that ignition trigger?

konakat

It is best to use a bit larger tip than you think when reflowing solder points. Larger tips are hotter, which is good because you don't want to sit on a solder point more than a few seconds. The longer it takes to reflow the solder, the more heat wicks up the lead and into the package of the electronic component attached to it. It is also a good idea not to reflow all the leads on a large package in a row, so that you aren't concentrating all the heat onto one device for several minutes. Jump around to give the device time to cool between applications of heat.

mytrplseven

On using soldering equipment, get a fresh wet household sponge (like the kitchen ones) and keep it just damp, not dripping and every few soldering applications, wipe the tip on the sponge and apply a little solder to the tip right after. The searing of the tip steam cleans the old residue away and the new solder applied to the tip "re-tins" it so it'll work clean and faster. This is a practice all professional soldering techs use, especially on aerospace applications.

Recommended wattage on pencil irons is 60 watts so you don't do heat damage to wire traces (lands) on circuit boards or small components.

Shown is a Weller soldering "station" commonly used in professional shops (note yellow sponge) goes for minimum of $145 but a simple pencil iron of proper wattage and damp sponge can be had for less than $20 at Radio Shack.

PelicanParts.com

Great video - thanks for sharing!
Mark/Pelican Parts

Dash01

I don't have the number handy, but got it some years ago for about $5 from DigiKey in Minnesota. If you have the number printed on the stock DME ignition trigger thingy, perhaps that number will cross-reference with a DigiKey part number.