TR Magna
2.6 Litre
4 Cylinder
Manual
EFI

Problem:
I replaced the distributor cap, rotor, HT leads, spark plugs, alternator regulator pack and starter motor about three months ago with little use since then. The old girl ran fine until a few weeks ago when she decided to stall just a few hundred metres from home.

Symptoms:
• The car turns over however 90% of the time it will not start. If it does start, it may run for 5 seconds or 5 minutes before it cuts out. The engine shudders as it attempts to stay running at times then cuts out.

• When it finally cuts out there is a highly distinctive sound of a ‘crackling’ noise suggesting a make/break sound of contacts, I have no way to tell, but seems to be somewhere way under the inlet manifold. The sound never lasts long enough for me to identify the exact source as it is a very low volume crackle (I live on a busy street with a rail line that seems to want to send a train along every time I need to hear what's going on :rant: ). The crackle may be of just a few snap/crackles or last for approx. ten to thirty seconds before it stops.... but never loud, so I guess it has to be milliamp arcs that I'm hearing.

• I have reset the ECU by disconnecting the (Neg) battery. When reconnected and after successfully running for a few minutes I get error code 31 suggesting that the knock sensor is faulty.

• If I disconnect the knock sensor from the main loom underneath the fuel rail I still have the same symptoms (ie. failing to start or limited running time) and still have that elusive crackling noise.

* Just to complicate issues.... I have also had an oil leak from the tappet cover (which continues as I haven't replaced the seal yet) and contaminated many areas along with forgetting to replace the oil cap after refilling well before this problem. If I had the money and council approval I'd buy a steam clean engine and give the motor a huge going over. But the car won't drive to Bunnings or whoever... LOL.

The problem seems very confusing as the crackle does not not sound like its coming from the knock sensor but still seems to co-incide with stalling of the engine.

My intention is to replace the:

* Knock sensor and lead including the connector next to the fuel rail.
* Power Transistor (as both my analogue and DMM meters readings conflict with what my manual says is OK.... even though I disagree with the manual on the readings an NPN semiconductor should read, neither confirm my belief that the transistor is OK)
* Ignition coil - which hasn't been replaced in the past two years
* Fuel Filter - This was replaced about two years ago.

Questions:

* Does anybody have a genuine idea of what might be causing this ?

* Is there any way of checking the knock sensor without removing the fuel rail, plenum chamber etc. as it looks like a mongrel of a job ?.

I know about the Inlet Manifold support bracket and those mongrel bolts because I had to replace the starter motor recently and don't want to have to go through all that again.

I have both digital and analogue multimeters to assist in fault finding.

Please help if you can as I'd really appreciate it.

this is gona sound realy silly but ohnestly get a mechanic to check it out for you,who ever regulary services your magna should be able to help you out,DIY mechanics isnt realy much help if you dont know everythin,ohnestly if you need your car to use soon get it looked over by a mechanic.
my bet that it is either the alternator or the starter motor although my knowledge on engines is not all that good,lucky there are a few mechanics on the magna forum who wil glady help you out when they see this thread:)

Hey Magna Buff,

Thanks for the tip, however I can't find "old fart" when I searched for him. Do you have his correct or full username so that I can try again ?

Thanks:) :)

Ol' Fart is his forum name

this might sound stupid but wiggle the tps wiring connector to different places and try it. sounds like what sometimes happens to me. corrosion in the tps plug means it sometimes doesnt connect

Hi Hendrik
Did you fix the problem?
Sounds like the "crackle of doom" from the ECU. Couple of links attached with some detailed info about unstable ECUs due to filtering capacitors and other woes.
It would fit well with the symptoms you described including weird fault codes.I've had first hand experience of this in a 91 TR. ECU with leaky capacitors & faulty driver chips.Fixable but challenging as it destroyed the ISC motor as well but that's another story.
Units can be bench tested by people like Automotive Service Solutions who also fix them.
If you think it might be the problem be careful about swapping in a module from a donor in case it gets fried.
http://www.tmo.com/howto/ecu1g/caps.htm
http://www.dsmtuners.com/forums/showthread.php?t=116585
Good luck

Go Here, very helpful

http://www.troublecodes.net/mitsu/

Also

P0001-P0099 - Fuel and Air

P0030 HO2S Heater Control Circuit Bank 1 Sensor 1
P0031 HO2S Heater Circuit Low Voltage Bank 1 Sensor 1
P0032 HO2S Heater Circuit High Voltage Bank 1 Sensor 1

Also

2 DIGIT NON EOBD FAULT CODES

24 Idle Control System Malfunction
23 Mass Air Flow Sensor Circuit
22 Knock Sensor
21 Engine Coolant Temperature Sensor
18 Electrical Load Signal
13 Camshaft Position Sensor
12 Starter Signal
11 Crankshaft Position Sensor
37 Rear O2 Sensor Circuit / A/F Sensor Circuit Malfunction
35 CPC System
33 Vehicle Speed Sensor
32 Oxygen Sensor
31 Throttle Position Sensor Circuit
29 Crankshaft Position Sensor 2

Hope this helps

If the TPS is gone it will cause your car to stall, happened to me.