I wrote last week about a continuing no-start situation with my vehicle.

I was driving while I noticed a loss of power, then the car died. After having it towed to my house and waiting three hours, it started up twice. That was two weeks ago. It has not started since then.

OBD-I codes were 1-1-1 for ignition and fuel injection. I checked the starter, alternator, battery, fuel pump, fuel filter, spark plugs for spark, distributor and timing belt for rotation; all were normal.

There is no spray from any of the fuel injectors on cranking the engine. On removing the fuel rail, I heard a hiss, which I believe was fuel pressure (I have not tested fuel pressure).

I went to the ECU and found all signals were normal (ie voltage and resistance for AMM, rpm sensor, fuel injectors). Ground is normal.

I spent all last weekend looking in junkyards for the infamous 0 280 000 561 ECU, but couldn't find it.

Is there a way to test the ECU itself? Am I missing anything else?

i dont know what iam doing with it but i have a ECM with BOSCH 0 280 000 561 ON IT!!!!!!!! if you pay for shipping ill send it to ya i got no use for it....

Miike: Some people have all the luck and it looks like you're one of'em. jp

If you do in fact have fuel pressure and spark, the injectors must not be opening. If you have a volt meter or test light, see if the ECU is sending 12 volts to the injectors by pulling one injector plug and connecting the meter or light up to it and crank it over. The best method for testing an ECU is finding one to borrow that is known to be good and substituting it. Of course the trick is finding one to borrow. jp

Adding to Dan and Randy's tips—if it runs with jumper from Fuse 6 to Fuse 4 (bypassing the Fuel Injection relay), see if the ECU is failing to ground the Fuel half of the relay during cranking.

Use a voltmeter to Back-Probe the relay connector BL/GN wire (terminal 86/2). This point should be grounded by the ECU when it gets an "OK" from the Ignition CU.
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Bruce Young
'93 940-NA (current) — 240s (one V8) — 140s — 122s — since '63.

a 556 will also work. Good luck Dan
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85 245 M46 191K, 92 245 A70 118K

What are you missing? All the fuses clean? 25 amp fuse on driver's side inner fender clean? What happens when you place a jumper wire between fuses 4 and 6? The pumps should run when you have the jumper in place. If the pumps run with the jumper in place will the car start? Does it start with the jumper in place and stall when you remove it? Are you sure the fuelpump relay is any good? If you are absolutely sure, without a doubt that the fuelpump relay is good and it will only start and run with the jumper between fuses 4 and 6 then I would say the ECU is bad.

Why are you looking for a 561 ECU? The 951 is the one you should be looking for to replace a 561.

Randy

Is the 951 ECU better than the 561?

Yes, the 561 is the one that causes a lot of problems.

The 951 is the replacement for the 561 that was prone to failure. Dan
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85 245 M46 191K, 92 245 A70 118K