No light on ECU, no fuel pump

[57Airhead]

Hope someone has an idea for this:

The motor: 2160 CB Performance 2nd gen fuel injection

History: New motor, took delivery a few months ago, have finally got it in and fitted and fired it up last Friday fortnight for the first time, only briefly, turned it on and off maybe five times total, but not running for extended period at any one time. No problems. Went surfing for a week's holiday.

The problem: Started it up again today, just for kicks (got a few more things to do before it comes down off of the stands), and it wouldn't turn off. Had to pull the battery positive to shut the whole thing down. Reconnected the battery +ives, turned the key to the On position, and the fuel pump isn't spinning up and the light on the ECU is not coming on.

I have shoved a test lamp in the ignition wire connector, and it seems okay.

So, any idea why (1) it wasn't turning off and (2) why the ECU and fuel pump are now not indicating any life. Would a cranky trigger terminal (86?) in the fuel pump relay cause such a problem?

[Dale M.]

Hello.... "CB Performance?.... Connect me with tech support ( Pat D.) please"...

Any fuses into ECU... Check all power inputs from battery to ECU and relays ... Check for relay function...

Dale

[57Airhead]

Hello.... "CB Performance?.... Connect me with tech support ( Pat D.) please"...

Any fuses into ECU... Check all power inputs from battery to ECU and relays ... Check for relay function...

Dale

Hi dale, yeah, all fused inputs seem fine, but I do have a question mark over the fuel pump relay (though not sure why this would affect the light or function of the ECU). Unfortunately, communication with PatD seems to have broken down as I've been waiting for a guide and blueprint for this engine, but after repeated requests over 6 months I've given up.

[Dale M.]

If relay is controlled by ECU and not direct power from key switch I would venture a guess ECU is fried...

Do you have any schematic how relay is wired.... Does it have 12 volts on one side of relay winding and a ground from ECU to operate? ( like MS)...

It should take +12 volts on 86 and ground on 85 to operate relay ...

http://www.thesamba.com/vw/forum/viewto ... ?p=6016062

IS diagram in "the samba" thread good?

Do you have constant 12 volts on pin #9 (from battery)

With key on do you have 12 volts on pin #8 (from ign switch)

With key on do you have 12 volts on pin #7 (out to fuel pump relay)

Dale

[57Airhead]

Thanks Dale for helping me work through this. You were right: the run-on situation was rectified by splicing in a diode to the field terminal of the alternator. For anyone who might have a similar problem, the diode you want is #1N4001, should be able to get from most electronics supplies stores. The stripe on the diode goes toward the alternator when you splice it in. Put it in backwards, and your bus won't start -- or at least that's what happened to me (What are the odds? A 50/50 chance of getting it right and my first attempt is wrong )

A temporary solution before you get the diode is to stomp the brake pedal when you've switched off the ignition and this should kill the engine.

The ECU just needed to be rebooted. Pulling the battery power while it was still on didn't let it go through its shutdown procedure and save all its settings for the next startup. Again from anyone in a similar situation, pull the main comm bus from the back of the ECU with the bus off; turn the key to the On position and plug it back in. That should reboot it.

[Dale M.]

Cool.....

Its the little things that screw with your mind....

Dale