urgent need for auto electrician in Kent /Bexley area

[akita1]

Morning all Can anyone recommend an auto electrician to help with an ongoing problem with my brothers vauxhall vivaro people carrier for some time now it has been suffering fro m a pretty violent intermittent misfire which several so called specialists have failed to rectify last night it finally broke down the AA came out and were great and have diagnosed an open circuit to injector no2 so now we are pretty sure we have found the problem we are now looking for someone reliable to help rectify this so any help would be most gratefully accepted many thanks Bill.

[ingenieur]

I think you just require an ordinary mechanic. Probably to replace the injector as a first step. If it continues then investigate wiring. Can test to see if there is an open circuit in the wiring without replacing anything and that's an easy test to carry out.

[BertBert]

Just curious as to what that means, open circuit to the injector. Do they not spend most of their time at zero volts with 12v pulses fire the injector?

[ingenieur]

BertBert said:

Just curious as to what that means, open circuit to the injector. Do they not spend most of their time at zero volts with 12v pulses fire the injector?

The language used in vehicle diagnostics systems varies but generally speaking open circuit means if any current is applied to the object it'll go straight to ground. Generally indicative of a failure of the component or the wiring to it.

[Richard-D]

ingenieur said:

BertBert said:

Just curious as to what that means, open circuit to the injector. Do they not spend most of their time at zero volts with 12v pulses fire the injector?

The language used in vehicle diagnostics systems varies but generally speaking open circuit means if any current is applied to the object it'll go straight to ground. Generally indicative of a failure of the component or the wiring to it.

No, that is not an open circuit.

I wouldn't go winging parts at it as suggested above. If you want to play swaptronics switch the injector with another cylinder and see if the fault moves with it. If it doesn't then it is a wiring or ECU issue.

What engine is it? Makes a difference how i would go about it as some are easier to swap than others.

Edited by Richard-D on Sunday 5th March 09:37

[BertBert]

ingenieur said:

The language used in vehicle diagnostics systems varies but generally speaking open circuit means if any current is applied to the object it'll go straight to ground. Generally indicative of a failure of the component or the wiring to it.

That's a closed circuit. An open circuit is a bulb connected to a battery with two wires and it doesn't work because one of the wires is broken.

ETA an open circuit on an injector would mean that it's not getting the 12v to activate it. That feels hard to diagnose in my view without a scope.

[Richard-D]

BertBert said:

That's a closed circuit. An open circuit is a bulb connected to a battery with two wires and it doesn't work because one of the wires is broken.

ETA an open circuit on an injector would mean that it's not getting the 12v to activate it. That feels hard to diagnose in my view without a scope.

Injector coil itself could be failed open/high resistance. Easy test with multimeter.

Wiring to injector, same as above.

Common to have full time power to injectors with a switched earth via ECU. Easy to check for power to injectors at connectors.

Very rare to need a scope for this fault.

In fairness to OP he did ask for recommendations for an auto electrician though so this probably doesn't help him. Sorry to go OT.

Edited by Richard-D on Sunday 5th March 10:56

[ingenieur]

Richard-D said:

ingenieur said:

BertBert said:

Just curious as to what that means, open circuit to the injector. Do they not spend most of their time at zero volts with 12v pulses fire the injector?

The language used in vehicle diagnostics systems varies but generally speaking open circuit means if any current is applied to the object it'll go straight to ground. Generally indicative of a failure of the component or the wiring to it.

No, that is not an open circuit.

I wouldn't go winging parts at it as suggested above. If you want to play swaptronics switch the injector with another cylinder and see if the fault moves with it. If it doesn't then it is a wiring or ECU issue.

What engine is it? Makes a difference how i would go about it as some are easier to swap than others.

Edited by Richard-D on Sunday 5th March 09:37

Can't do that if the AA are required to provide the readout. No point trying to follow the fault from one place to another if you have no way of observing the fault changing places. Best as I said originally... test the wiring if you know how to. If not then change the injector and hope that fixes it. It's a bit risky and might not work... but so is employing a vehicle electrician or mechanic who might do the same thing and get the same result.

[ingenieur]

BertBert said:

ingenieur said:

The language used in vehicle diagnostics systems varies but generally speaking open circuit means if any current is applied to the object it'll go straight to ground. Generally indicative of a failure of the component or the wiring to it.

That's a closed circuit. An open circuit is a bulb connected to a battery with two wires and it doesn't work because one of the wires is broken.

ETA an open circuit on an injector would mean that it's not getting the 12v to activate it. That feels hard to diagnose in my view without a scope.

You'd check the other injectors with a volt meter to see how they respond while the engine is running.

[ingenieur]

Richard-D said:

BertBert said:

That's a closed circuit. An open circuit is a bulb connected to a battery with two wires and it doesn't work because one of the wires is broken.

ETA an open circuit on an injector would mean that it's not getting the 12v to activate it. That feels hard to diagnose in my view without a scope.

Injector coil itself could be failed open/high resistance. Easy test with multimeter.

Wiring to injector, same as above.

Common to have full time power to injectors with a switched earth via ECU. Easy to check for power to injectors at connectors.

Very rare to need a scope for this fault.

In fairness to OP he did ask for recommendations for an auto electrician though so this probably doesn't help him. Sorry to go OT.

Edited by Richard-D on Sunday 5th March 10:56

Primarily I'm saying an ordinary mechanic could probably fix this. As "Auto Electricians" are hard to find and work in unconventional ways that sometimes make them hard to employ it would be easier to get it to a normal mechanic. The bit about testing / fixing is just some reasoning to explain why it shouldn't require an auto electrician to fix it. Cars have had a lot of electronics in them for 30-odd years now and any mechanic who can't do electrics is screwed.

[Richard-D]

ingenieur - you are providing terrible advice that shows you have no understanding of how an injector circuit works or how you would use a multimeter to test it. It's an open forum so you are perfectly entitled to do so but it is certainly not going to help the OP.

ingenieur said:

You'd check the other injectors with a volt meter to see how they respond while the engine is running.

No, you wouldn't!

[ingenieur]

Richard-D said:

ingenieur - you are providing terrible advice that shows you have no understanding of how an injector circuit works or how you would use a multimeter to test it. It's an open forum so you are perfectly entitled to do so but it is certainly not going to help the OP.

ingenieur said:

You'd check the other injectors with a volt meter to see how they respond while the engine is running.

No, you wouldn't!

And yet.... blow me down... lo and behold... would you adam and eve it... in an official service manual from a vehicle manufacturer (doesn't matter which one) there is the effin procedure for testing injectors with the engine running.

[Richard-D]

That test isn't testing the injectors. The fact that you clearly don't understand this proves my point. Strop about it all you like.

You don't know the difference between an open circuit and a short circuit.

You don't know the difference between testing an injector and testing an injector driver.

You suggest blindly throwing parts at the problem in the hope the item mentioned in the fault code is the issue.

I'm sure you are very knowledgeable about something but this is not it. Just stop.

[ingenieur]

Richard-D said:

That test isn't testing the injectors. The fact that you clearly don't understand this proves my point. Strop about it all you like.

You don't know the difference between an open circuit and a short circuit.

You don't know the difference between testing an injector and testing an injector driver.

You suggest blindly throwing parts at the problem in the hope the item mentioned in the fault code is the issue.

I'm sure you are very knowledgeable about something but this is not it. Just stop.

You're playing with words. i.e. if the word I've used it too general all of a sudden that means by your standards I'm entirely clueless and probably incapable of even going to the toilet by myself.

I already said it but primarily I'm suggesting in the first instance that there's no requirement for an auto electrician. The advice on changing the part is very much secondary and not the main emphasis of my initial response.

Supposing the guy did decide to try and repair it himself he could decide to test the circuit or replace the injector depending on the cost of a spare part. He might decide to eliminate the injector from the diagnostics by replacing it. Or if he did not want to spend any money he could do some tests. Which tests and how they are done depends on the vehicle to some extent.