ECU blowing problem

[philadams16V]

Hi all.  I have a 1990 mk2 16V and have a problem with the ECU which keeps blowing.  The problem started around 2 weeks ago when my car was struggling to start especially from cold and was running like a 1.3L.  I took the car to my local VW specialist (I dont understand engines a great deal) but he located the problem by using a strobe on the timing.  The car was running 30 degrees retarded, due to the blown ecu.  Luckily I had a spare ECU from my previous 1990 16V so I plugged it in and everythin was running smoothly again.

Until yesterday morning, I started the car and again idle was poor and the car struggled to start.  There was no power goin to the wheels in 1st gear.  I immediately suspected a faulty ECU  so I took the car back to my specialist.  He did the same check and again the car was running 30 degrees retarded, hense another ECU has blown.  He has checked the voltage which is giving out 14V, which suggests that electronics are ok.  Can anybody help me because I dont want to simply replace the ECU again and blow another one. 

[Gambit]

it must be shorting somewhere, and i suggest its in round the ECU itself as this can get wet if the scuttle covers are damaged in anyway. also put some lithium grease onto metal connectors to keep out the water

[KKK]

Clean up the chassis to gearbox housing strap.  If this connection becomes poor, the only earth for the starter motor is through your ECU (goodnight).

Clean all the other earth straps up too (rocker cover to coil, battery to chassis).

Use petroleum grease (i.e. vaseline) on connectors - lititum grease will disintegrate any rubber seals/boots.

[...joe]

^^^ hey i hpe your name is all about turbo's not white hoods young man!

[ridgers]

I was gonna ask if you have had a clutch fitted recently on this car as a common problem which was mentioned above is people forget to refit the earth leads from the engine/gearbox to the chassis and when you go to turn the car on for the first time you blow the ecu.

Check all your earths and also check your not letting the ecu sit in water. this time of year the two drains normally get blocked and you get problems.

[georgenewman1]

when you say earth to the coil were does it actually go to on the coil itself, the negative terminal or just the coil body?? cheers

[UKjarvis]

I blew my last one by not fitting the earth strap to the gearbox properly, definatly worth checking.

[clipperjay]

Another one from the grave lads  check the date it was posted yeah 2005?

There is an earth strap from the bracket that holds the coil two nuts I recall it goes to some earth point on the firewall or anywhere there is a decent earth! Don't get confused with the terminals on the actuall coil itself!