5M-E injectors not firing

[demios]

The saga continues..

The 22R igniter was too important to be out of commission for any length of time so we haven't dropped in a new igniter to diagnose.

Instead we pulled half the wiring harness out and cut out all the injector stuff, bypassing any potential shorts in the dodgy wiring- found two injectors with broken wires going in and a short between ground and resistor/power on one bank of injectors, also found that 4 or 5 out of 6 injectors were running off one bank / side of the resistor block. Ugh...

This looked like it might be the problem, but sadly cutting all that stuff out and simply hooking a noid light between the resister and the ecu still gets us no pulse, as before, so despite fixing up some really bad wiring we still haven't found the fault.

Tomorrow we might go to the wreckers again and get the igniter off the cressy we got the spare ecu out of.

Can we just confirm that the igniter signal goes to the pin on the ECU labeled "IG"?

Thanks for all the help so far guys, we really appreciate it.

[wilbo666]

Is it possible that you have damaged both ECU injector drives given the wiring issues you had?

Take the ECU apart and check the injector driver transistor would be my suggestion

Cheers
Wilbo

[RA35GT]

Diagram for you.

[thechuckster]

i extracted the ECU out of my old MA61 and fwiw, there's only one injector driver. SO even tho there's two pin-outs, they come from the same large 3pin driver.

Also, yes, the igniter signal goes to the IG pins and the tacho

Anyway, if interested, I have my ECU, dizzi, coil & igniter with me in Toowoomba.


7M-GTE MX73's Picture:
http://img697.imageshack.us/img697/8339/5mewiring11.jpg

edit: holy crap - that image is huge, changed it to a link

edit 2: fwiw, when i un-butchered the wiring in my MA61, i replaced the injector plugs with connectors pilfered from a V6 commode - unlike the denso plug, they're not brittle and they have a simple push-to-unlock thing.

[demios]

Well we opened up the ECUs and had a look inside. On the underside of the board around the large transistor bolted to the ECU case there is some obvious brown discolouration, presumably from overheating or something. Worse on the older ECU but still present on the more recently acquired one.

I guess the ECUs are probably fried?

We just received an engine today, 5M-GE, with an igniter bundled with it.. was going to try dropping that in and a new resistor pack to see if it makes a difference, but I'm starting to think we've already killed both ECUs. Does that sound likely to you guys?

Thanks.

[thechuckster]

I'd suggest you put a multimetre on the tacho-out from the igniter and crank the engine - no ECU needed - you should get a trigger for each plug fired. Once you know you have a IG trigger, then point finger at ECU. Am not sure whether you'll get a 12V signal or something more substantial so start with a high V(DC) setting on the meter and then drop down.

Someone here with a B.Eng (Elec) or similar may know how to test the actual driver (in situ or unsoldered from board. Wilbo?

Anyway, if your new 5MGE has the spark controlled by the ECU (no vacuum advance on dizzi) you'll need a different ECU (as the ECU drives the igniter) or use the dizzi and matching igniter from a 5ME.

If you guys are still in BNE, let us know if you need another ECU. You might be able to get another ECU from the wreckers claiming it was DOA when you got it (don't tell them about the dodgy wiring).

[demios]

Well.. false alarm. Again. This is like some sort of tragic comedy. We discovered this evening that the fuse to the EFI is actually getting blown when we crank the engine. (Yeah we did already check the fuses, honest. :/)

Swapped in a new fuse, cranked it and we got the tiniest little glow out of the noid light before the fuse blew again.

All that pointless effort..

Looking over the rest of the wiring now though, it's not surprising.. the fault could be anywhere.. it's really obvious that the car has just been sitting around for ages. After pulling the fuse box out we found a bunch of really dirty and corroded connectors. Tomorrow we'll rewire anything that looks obvious, then resume diagnostics.

On the plus side, both ECUs are probably alright (turns out Auto and Manual ECUs look quite different inside), and we found the really bad condition of the injector harness.. and the rest. Tempting to just pull the engine and stick the 5M-GE in after a complete rewire of the engine bay.

Oh also, I've been advised that we should get a 5M-GE suitable dizzy and swap in the internals from the 5M-E one if we want to run the new engine on the old ECU, but I'll definitely be keeping an eye out for a GE computer etc.

So.. what's blowing our EFI fuse?

[thechuckster]

you'll need one of these:

7M-GTE MX73's wiring diagram, and a carton or three of these:

to entertain you while you discover all other kinds of rootedness in the engine loom.

On the upside, the EFI fuse doesn't feed a huge number of things ... sort of.


edit: remove the circuit-opening (C/O) relay, if fuse continues to pop, then it's between the fuse and the ECU. If it doesn't then it's wiring from fuse to fuel pump (goes via C/O and AFM) or the air valve (low-tech aux-air valve - uses heated bimetallic strip to slowly close off air supply that bypasses throttle.

[Sammich]

wow...i totally dont feel bad for selling this for $500 now lol

dont forget you've still got oils + springs + sigma LCA's to come pick up off me if you still want em!

good luck with the wiring...I knew it was bad but maaaaan that shit is fucked lol

[demios]

wow...i totally dont feel bad for selling this for $500 now lol

dont forget you've still got oils + springs + sigma LCA's to come pick up off me if you still want em!

good luck with the wiring...I knew it was bad but maaaaan that shit is fucked lol

Yeah, I've stopped feeling sorry for you over the price, too. I've had this car for a week now and I'm already starting to get sick of it.. (- Phoebe)

[thechuckster]

when you 1J it, that smile will come back

[Sammich]

when you 1J it, that smile will come back

a 4A in it would put a smile on my face if it ran! lol

the 5m-ge should be plenty of fun as it is

[demios]

Woah woah, slow down..1J? We only just got the 5M-E running again!

.... yup the car moved under its own power this evening. Turned out to be a fairly simple wiring fix, so that plus the new injector harness and she started up happily... er.. except all the black smoke for 10 minutes and a squeaky power steering belt.

Of course, I killed it on the test drive. The air box was apparently just flopping around loose and one of the air hoses disconnected. Net result: engine revving at a consistent 4000rpm. Oh well, we'll bolt everything in properly and reconnect the hoses and thrash it around some more tomorrow.

Thanks everyone for all the help. Extra special thanks to thechuckster for the never ending stream of good advice, and 7M-GTE MX73 for that great diagram.

Members ride thread coming soon... 5M-GE on an engine stand ready to drop in during the summer.

[thechuckster]

5ME FTW! .. actually, that's all kinds of wrong

... waits for skid pics to load?

[Sammich]

well its going to Archerfield tonight...skid pics may very well be on the cards

i so dibs a drive in this thing tonight...