Long story summarised, my wagon started to miss then 1km later died on the M4 a few weeks back. NRMA diagnosed no spark, so had it towed home. I replaced the distributor with a brand new one and away it went, ran fine for a week (better than ever). Then it refused to start, an hour later started and ran but would die intermittently. Got it to an auto electrician who diagnosed a failed crank angle sensor.

So, fitted a new sensor, timing belt, water pump, plugs, leads and rocker gaskets etc, but I still have no spark at all, and no error codes. I have checked all fuses, and all the connectors, all ok. Replaced coil in new distributor with a new one, still zero spark.

Checked the voltages in the crank angle sensor socket, and I get 5v on terminal one (top left when looking at the socket) 12v on terminal 3 and earth on terminal 2. Gregory's manual says T2 should have 5v, earth on T1. Is this correct? If so can I assume the ECU has failed?

Anything else I should look for?

Thanks in advance for sharing your wisdom :)

could this be an immobiliser issue then I wonder

Would it not throw a code if the immobiliser was playing up?

Would it not throw a code if the immobiliser was playing up?

I have no idea but there have been reports of immobiliser issues in the earlier models, not sure if the TL/TW suffer the same issue but intermittent no go, new dissy and coil plus new crank sensor it's something I'd wonder about , could be ECU. I just throw that out there for thought, touch wood I've have not had an issue yet to have any real experience with. And as far as I know the ECU and TCU are combined so does that mean the heater pipe leak that can cause erratic trans issue also affect the ECU and give engine trouble

Engine control relay, supplies power to ECU, maybe also worth checking. I've never fault found a MPI system for no start on a Magna.

The sensor voltages are correct, though the pin order described in the manual I have is based on looking at the harness not the sensor so pins 1 and 2 are reversed. Looking at the harness and with ignition on, top left (1) = continuity with earth. Top right (2) to earth = 4.8 to 5.2V. Bottom pin (3) = battery voltage (12V nominal). So your sensor appears to be working as it should. When you say 'no spark' have you verified this or is this an assumption based on the NRMA diagnosis? Basic check is remove a front plug lead and shove in a spare spark plug if you have one. Make sure the plug body is touching earth (but not the sparking bit) and turn over the engine. If the plug sparks then the problem is either a weak spark (unlikely with what you've already replaced) or the fault is elsewhere, such as bad mixture or non-firing injectors. Also make sure you have a good, charged battery, if the voltage drops to below 8V while cranking it won't start.

If there's no spark check the distributor cap and rotor, which are about the only things in the circuit (other than ECU) not yet replaced. The carbon contact in the centre of the cap can get stuck in, make sure it's springy and not worn right down. If in doubt replace the cap.

Other things to consider:

1) Ignition timing (5° BTDC ±3°). Check installation of crank angle sensor
2) Maybe an immobilizer issue? Not sure what this manifests as but possibly allows cranking and blocks firing. May be a fault with the immobilizer antenna around the ignition key, I'm out of my depth here but others should be able to provide more info.

Otherwise you'll need to get it to an auto-elec with a MUT-II diagnostic tool and enough patience to track the fault.

Beat me to it TW2005 re immobilizer. If the antenna can't read the key it won't start the car, this isn't technically a fault since the same would result if the wrong key was used. Do a search on this forum re immobilizer issues, I believe it's common and there's a few ways to fix or work around.

Good point on the relay, I'll check that tomorrow. No heater leaks, so moisture is not the problem. I have no idea how to check the immobiliser, but I'll look into it. Thanks for the suggestions.

not sure if this helps at all or complicates things

https://lh3.googleusercontent.com/rq2_ZFB4MhTMA28q57ElXOJZUs_stGpn37zIHLYBtaA=w774-h643-no

Definitely no spark. Fuel system is fine, plugs are wet after cranking. I was thinking of an immobiliser fault showing a code, but a failed antenna would not show as a fault, so no code generated. I suspect this is the most likely culprit, will investigate further.

harness pinout, I assume this is the harness end

https://lh3.googleusercontent.com/g10pNYiQ6BDLpwg5nptorWqqi-KeN5vDWKCPnx9BeeQ=w62-h55-no

That was my assumption too TW2005, the socket is marked '2' on the top right. Mine has 5V on pin 1, nothing on 2, hence my first question. Reading the instruction you posted would suggest the opposite outcome is normal.

Looks like I also need to load test my battery to eliminate that from the equation too. It's only 6 months old, but you never know.

yeah, really need someone qualified and experienced with these sort of issues. Touch wood I've found the old maggies pretty reliable although I'm keeping mine for some time yet, will be interested in how this turns out for my own knowledge.

This has been posted before but it may the issue with the immobilser - hope it helps - http://martybugs.net/articles/magna-stall.cgi

Just to update this thread, I have solved the problem. The new distributor was the root issue. I went back through everything I had done and decided to rebuild the original distributor and try it. Bingo! Started first kick. I think what had happened was this: the new distributor was fitted with new leads and plugs in front three cylinders as I didn't have time to do the rear three at that point. I suspect the rear leads were shot and high in resistance. This has resulted in the failure of the sensor in the new distributor (not sure what this is called - cam angle or TDC sensor?). I replaced the coil in the original dissy, and together with the original sensor all is now well (plugs and leads in rear three cylinders were changed prior to this). Hopefully all should be fine from here, but I will keep a close eye on everything.

Just to update this thread, I have solved the problem. The new distributor was the root issue. I went back through everything I had done and decided to rebuild the original distributor and try it. Bingo! Started first kick. I think what had happened was this: the new distributor was fitted with new leads and plugs in front three cylinders as I didn't have time to do the rear three at that point. I suspect the rear leads were shot and high in resistance. This has resulted in the failure of the sensor in the new distributor (not sure what this is called - cam angle or TDC sensor?). I replaced the coil in the original dissy, and together with the original sensor all is now well (plugs and leads in rear three cylinders were changed prior to this). Hopefully all should be fine from here, but I will keep a close eye on everything.

Not sure what to make out of what you report but sounds like original Dissy had bad coilpack, replacement had faulty sensor but I don't get the relationship between faulty sensor and bad leads on the rear bank. What resistance we talking on the leads? They will show K ohms and will depend on the length of each cable

Unfortunately I binned the old leads without checking them. They looked like they'd been there forever, hard and brittle. The auto electrician who diagnosed the faulty crank angle sensor told me that high resistance leads could damage sensors, and it seems the only logical conclusion - the car ran fine for a week after replacing the distributor (but with the old leads on the rear bank) before it failed.

Unfortunately I binned the old leads without checking them. They looked like they'd been there forever, hard and brittle. The auto electrician who diagnosed the faulty crank angle sensor told me that high resistance leads could damage sensors, and it seems the only logical conclusion - the car ran fine for a week after replacing the distributor (but with the old leads on the rear bank) before it failed.

glad it's sorted, what mileage does it have?

191,000. I'm the third owner, bought it with 155,000 on it, been trouble free until now. Hopefully it will stay that way now :)

I didn't see this thread, just for those involved: If you are missing spark, it's not the immobiliser. The immobiliser cuts fuel via a relay just under your radios/cd players, which the op said he was getting plenty of.

Thanks Neo, I'd figured that from other posts about the immobiliser. The lack of any error codes kept me focussed on the distributor, but I really didn't expect it to fail a week after purchase, hence checking ever other possibility first.

I didn't see this thread, just for those involved: If you are missing spark, it's not the immobiliser. The immobiliser cuts fuel via a relay just under your radios/cd players, which the op said he was getting plenty of.

Aha, thanks for the clarification Neo.