Club 80-90 Forums

Colinthefox,

Thanks so much for your advice. I did the starter test covering your post and according to Bentley procedure and all works correctly. So club member 300CE (Justin you top fella) sourced a telephone number of a local Kent auto leccy called Pete 07814029694. Despite being on holiday he talked me through a few procedures and is convinced internal failure of ECU is most probable.
So to Rob...
Many thanks to all contributors. Will come back with outcome in a week or so.
Regards
Stuart

If you have 0 Ohms you have a dead short to earth in the loom or a flawed test. If the injector circuit has gone short to earth the injectors will be held open constantly. If it was an internal fault in the ECU your loom would test correctly.
The priming time is controlled by a timer in the ECU, there's no pressure switch and no bimetallic switch.

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ajsimmo wrote: ↑24 Jun 2021, 17:50 If you have 0 Ohms you have a dead short to earth in the loom or a flawed test. If the injector circuit has gone short to earth the injectors will be held open constantly. If it was an internal fault in the ECU your loom would test correctly.
The priming time is controlled by a timer in the ECU, there's no pressure switch and no bimetallic switch.

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So back to square one, then!
Well l do have an ECU winging its way to me as l type. But l understand your verdict, Andrew.
All other ECU, TEMP 2 potentiameter, Hall unit tests hit spec everytime. They are very straightforward. Multimeter on OHMS setting predominantly. Or cranking voltage or volts close to battery condition
For injectors its is very basic.. Remove ECU plug and test circuits between pins:
11 & 7 cyl 2
12 & 7 cyl 1
23 & 7 cyl 4
24 & 7 cyl 3
All came back zero OHMS. Spec is 14-18.
Yet testing earth between pins 7 & 25 gives good ground connection for ECU plug. Earth lead on left hand engine cylinder to no 7 pin has excellent continuity too
So what am l doing wrong?

The main reason electrician believes faulty ECU is because of a test he ask me to make sure injectors are not stuck open as they batch fire as one.

As l recall it...it has been a long day!

Remove injectors. ECU plug in. Turn key to position before cranking engine. Fuel pump fires away. Injectors spray continuously.

Next.
Injectors still removed with their individual connectors removed. ECU plug in. Turn key to position before cranking engine. No pump and no spray.

Next
Injectors removed. Individual connectors in injectors. ECU plug removed. Turn key to position before cranking. No pump and spray.

On reflection that looks like an earth issue.
Im getting very confused and need to step away for a day or two.

I have no experience of injection on these but those over on the dark side (The Samba) note that:

"if one injector shorts internally, it will cause all the injectors to spray continuously and quickly flood the engine"

Suggestion there is unplug injectors one at a time to see if unplugging one fixes the issue.....

Test between pins 7 and an injector pin (any). When connected you are getting 0 ohms. With all injector plugs disconnected do you get the same, or infinite resistance, ie no connection? You should get the latter. If it's still 0 all the wires in the loom must be shorted together somewhere. Test for continuity between injector pins and mismatched plugs.

If it were one injector gone zero resistance, under the connected test you'd only get 0 ohms on that pin, and still get a measurement of the resistance of each good injector on the other 3.

Did you try disconnecting the ignition amplifier? The injection is pulsed from this according to the frequency from the hall sensor. See if the problem stops then.

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Thanks for the answers, T25 and AJ.
Im 60 miles away from camper, now back in Margate.
No l didnt disconnect individual injectors or amplifier. Sound advise from both thanks. Will head back tomorrow for more testing and action your comments.

Regards
Stuart

Fitted loaned (top man, Rob!) ECU. Pump cycled as it should. Cough and a spluttter and she lives again! Woooohoooo!.

ECU failure.

Now I didn't expect that. Good to hear the outcome, even if I was wrong.

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I assume you don't need the loom now stu
Didn't see this post til after I PM'd you

Glad its sorted.

Spoke too soon! Tickover very erratic. As if on two cylinders. will whip out plugs and put back in previous fuel regulator

Fun and games huh 

Keeps fouling the plugs

Refuses to idle smoothly. Adjusted timing ever so slightly either way. No joy. So back to best position.
Oil bubble blowing from pin hole top of tower. No petrol mixed with oil. Cant read level due to parked up a slope
Should l change oil and filter?

Got it! The bloomin lead between coil and dizzy cap failing. Waiting for third whammy!
Its a little bit shaky after l moved timing. But good enough for journey home. Just moving it to level ground to check oil.