Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[JamesV6CDX]

Back to dodgy wiring - try the continuity check, then wriggle any wires you can - I suspect it might have worked on the right settings -then it loses the decent signal and picks up whatever it can.  If the impedance is high enough, so will the induced voltage be..

Please don't tell me you've spotted a blue block of death on the wiring...the one which calls itself Scottish...

The wiring is disgusting, were way too many faults to fix in a day

[philhoward]

Oh dear...I spent half a day and far too much heatshrink on mine.

I know its "chasing your tail", but worth dropping a new wire from ECU to ECU, cutting the old one free?  PLease tell me if this is a grandmother and egg sucking suggestion...

My money is on the cr@ppy wiring...

[JamesV6CDX]

Oh dear...I spent half a day and far too much heatshrink on mine.

I know its "chasing your tail", but worth dropping a new wire from ECU to ECU, cutting the old one free?  PLease tell me if this is a grandmother and egg sucking suggestion...

My money is on the cr@ppy wiring...

I agree exactly with what you're saying.. unfortunately once we'd fixed the coolant issues and other bits, it was getting dark/late and I had broke my multimeter, so with no spare wire, we had to call it a day

[philhoward]

I know the feeling -I feel the pain!

We all forget the silly things from time to time  - hence the silly suggestions/memory joggers.  Please don't think I was being sarcastic - I wasn't.  I think it was you nudged me to to my daft mistake on mine (Manual valve on the tank  )

Is the wiring a "to be revisited"?  Seems a crying shame to be so close, having come so far.  Has to be said, excellent work to date!

[JamesV6CDX]

I know the feeling -I feel the pain!

We all forget the silly things from time to time  - hence the silly suggestions/memory joggers.  Please don't think I was being sarcastic - I wasn't.  I think it was you nudged me to to my daft mistake on mine (Manual valve on the tank  )

Is the wiring a "to be revisited"?  Seems a crying shame to be so close, having come so far.  Has to be said, excellent work to date!

Oh, the last points will be revisited!!

[Kevin Wood]

I agree exactly with what you're saying.. unfortunately once we'd fixed the coolant issues and other bits, it was getting dark/late and I had broke my multimeter, so with no spare wire, we had to call it a day

Remember it's not necessarily only the wire to the green tacho wire that's the potentially the problem. If the negative supply to the LPG system is bad, this will cause problems as the LPG injectors pull current, because it acts as a reference for all the signals from the rest of the car.

Kevin

[philhoward]

Ah yes...especially if you have 3 or 6 1 ohm solenoids pulling at once...thats a lot of amps...and probably only a bit of 0.5mm (if that) cable to cope with it.

If some chipmunk has spliced it onto a bad/small gauge earth, then the volt drop will be very significant..

[JamesV6CDX]

Remember it's not necessarily only the wire to the green tacho wire that's the potentially the problem. If the negative supply to the LPG system is bad, this will cause problems as the LPG injectors pull current, because it acts as a reference for all the signals from the rest of the car.

Kevin
 

I've also checked earths and ECU 12v feed is ok.

 

[Kevin Wood]

 :-/

Does the RPM indication on the LPG ecu appear stable and does it follow th real engine RPM or is it jumping around and a bit unstable? Does pulling the wiring about affect it?

Kevin

[philhoward]

I've also checked earths and ECU 12v feed is ok.

 

The 12V may well be solid - but the earth may require a better look..

[JamesV6CDX]

Have a look at my post that you quoted - states the earths are OK

[Marks DTM Calib]

Where are the 0V's to (remember, a car does NOT have an earth!), is it close to where the petrol ECU picks its 0V from or miles away!

Also, where is the rpm signal connected to, right close to the ECU pin or miles down the loom?

The ideal would be to check the rpm signal integrity with a scope at the LPG ecu.

[SteveD]

It might be worth screening the gas ecu if it's somewhere it  could pick up interference. If it's a metal case check it's grounding out ok or add a separate earth.

[Kevin Wood]

:-/

Does the RPM indication on the LPG ecu appear stable and does it follow th real engine RPM or is it jumping around and a bit unstable? Does pulling the wiring about affect it?

Kevin

I think this is the key to whether it's a configuration issue or an electrical noise issue.

Kevin