Running on 4 cylinders, Emerald ECU

[Flix]

Discovered that my Autograss car is only running on 4.
Definately a fueling issue, injector number 5 is not firing.
I've swapped the injectors round, still no number 5.
Am I right in thinking that it must be a broken wire, bad connection or ECU fault?
Any tips on what to try would be appreciated

[MWT5]

If the loom was made for the emerald could possibly have a break in it or loose connection in the injector plug. Can't you change the wiring plug off the injector next to it and see if the problem follows the plug.
If it does looks like your stripping the loom back to find a bad connection or a break in the wiring.

[Flix]

Will try that tomorrow, and check for continuity from ECU to injector plug.

[Flix]

Is there a way to see if the injector is getting a signal from the ECU?

[Volvostorm]

Yes, you can use a noid light, it just plugs on to the plug that goes on to the injector.

http://www.ebay.co.uk/itm/DRAPER-57798-INJECTOR-NOID-LIGHT-KIT-6-PIECE-/140615438997?pt=UK_Hand_Tools_Equipment&hash=item20bd555295

[Flix]

Thanks Paul, ordered a set

[Flix]

Checked wiring, all seems OK.
Got continuity between injectors and ECU, got 12v at injectors.
I'm thinking now that I'm on the wrong track.
Number 5 plug is clean/dry. If I remove plug leads one at a time, the engine note changes, unless I pull number 5, then no change. Got a good spark.
Engine has no knocks, bangs or odd noises.
Now thinking bent valve, could that give these symptoms?

[glock19]

You might have to remove the spark plug to have a look. Happened to me last saturday (5th May). I have fairly new plugs (less than a month old) and misfiring on cylinder 4 (pulling out the HT leads one-by-one with the engine running. Change a new set of HT leads - same problem. Then change another ECU - same. So moved on to removal of plugs. When I took out the fourth plug, a piece of carbon was squished between the terminal and the electrode. What a chance.

Clear the carbo soot, fixed back the old HT lead and car is on the move again.

[Volvostorm]

Try doing a compression check on the engine to.

Though, having a dry plug still points at being fuel related to me.

[Flix]

Will do a compression check this afternoon.
I've swapped plugs and injectors around, new leads, plugs etc.
Noid lights ordered, so they will prove the wiring for sure,I'm not good with electrics.

[Flix]

Compression test results,
From cyl 1
155,160,135, 145 and 160.
So it would rule out a mechanical fault, back to fuel issue I guess,

[Volvostorm]

Pretty much, 3 & 4 are a touch low, but not enough to cause major problems.

[Flix]

Removed injectors again, cranked engine while holding them, could feel pulses on all except number 5, swapped injectors, same.
So it would appear that my electrical testing skills are worse than I thought.:)
Now to find someone who has those skills.

[Volvostorm]

Has this problem just started? Could be a problem with the Emerald ECU, an injector driver might have burned out, the noid light will help

[Flix]

When I bought the car I changed plugs etc, and noticed plug 5 was clean. So it's been like it a while.
Might have to send the ECU to Emerald to be checked over.

[Flix]

Spoken to the guy who built the car. He thinks that it's an ECU issue. Either the driver has failed or somehow the ECU has been altered somehow.
Will ring Emerald, see if they can check the ECU and settings.

[Flix]

ECU gone to Emerald for testing/repair. Hopefully back in 7 to 10 days.

[Flix]

Result. Posted the ECu yesterday, just had a phone call, injector driver repaired free of charge. Will get it back tomorrow.
Big thumbs up to Emerald.

[Volvostorm]

Thats great news :)

Well done Emerald too for being helpful.

[Jamest5r]

Result. Posted the ECu yesterday, just had a phone call, injector driver repaired free of charge. Will get it back tomorrow.
Big thumbs up to Emerald.

Always nice to get good customer service no matter where and when :)

[kfc]

Always a good recomendation. When you here it on a place like this.

[Flix]

Receivedan email from Emerald, stating that the driver had possibly been overloaded.
He suggested I check the resistance of the injectors, should be between 10 and 16 ohms, easy enough.

But then suggests "Also check that there is not a +12v short to the injector signal wire, i.e. between +12v and ECU pin 1."

Can someone explain in electrical numpty terms? Thanks

[bubba_1986]

He means get a meter and check continuity between +12v supply and pin 1 on the ecu.U know when u set the meter so it beeps/buzzes when u touch leads together. Put one lead on the +12v supply and other lead on pin 1 of ecu. If it beeps u have a short, well according to what u say. If it doesn't and gives u a infinite reading u are ok

[bubba_1986]

to check the resistance of the injectors set your meter to ohms and within the 0-100 range, or lowest u can. Use both leads either way on terminals of injector and take the reading off of the screen and compare

Hope this helps

[Flix]

Thanks Bubba, makes sense now.
Tested injectors all read 14.5 Ohms.
Will check for a short later. Had a word with the electrician, he says a short would be obvious, melted solder or burnt wiring.

[kyboy]

Dave walker at emerald is a top man, always willing to help and a clever bloke, got a few mates who have had work done there, and can't praise them enough!

[Flix]

Tested wiring as Bubba suggested, no faults, so refitted ECU.
Running on 5 now, sounds much crisper and livelier.
Thanks guys for the help and advice.