G'day all.

Car is a 1993 TR 4 cylinder EFI belonging to my partner. We are getting it going again after a year 'out to grass' so it can be passed on as a first car for her son. With a new battery and some fresh juice it started right up. A friend serviced it - new oil, filter, all fluids checked, tyres rotated, etc, etc. Took it for a good hard drive and it felt great.

I booked in for a roadworthy test, arranged a temporary vehicle permit and all seemed good to go. But this morning it was hard to start and when it did run it kept dying. When this was happening there was a lot of clicking coming from the glove box area. The manual helped - I removed the glove box and found the fuel pump control relay. This goes clickety-click every time the engine dies.

So, I'm wondering what to do next. I have tools and am no stranger to mechanical tinkering, but mostly on pre-computer vehicles. I have a similar Magna (1992 4 cyl) so I guess I could simply swap parts until everything works.

Any clues to lead me on a logical path would be greatly appreciated.

My TP wagon has a fuel control relay and I have the circuit diagram of this unit somewhere. It is a relatively simple unit. I suggest you change parts to check if it is the relay unit. Functionally, it does 2 things in the TP and presumably in the TR. My TP is a carby and not EFI.
1. stops the fuel pump when the engine is not running but the ignition is on. With the engine running, it takes ignition system pulses to keep the 12 volt supply to the fuel pump alive.
2. when the starter key is turned to start, the 12 volt supply is connected to the fuel pump.

Because of the history of the car, it might be something simple like a dodgy connection at the relay socket.

There is a TR/TS manual somewhere on this site.

Thanks Rumpfy. I have the PDF of the manual (all 1364 pages!). I have been reading, reading, reading.

So far I have checked the ECU fault codes (results are Normal - continual short high/low). I swapped the fuel control relay from the other car - no improvement.
Next, I'll be trying to power the fuel pump from a spare battery, and I guess it wouldn't hurt to swap the ECU after that, having read about buggered capacitors causing problems.

I have read far too many threads on this forum too. I'm learning heaps, but with that has come the realisation that the problem could be caused by an enormous number of little things.

Is it possible there is some kind of problem with the fuel circulation. I think the fuel circulates from the pump to the injection line and back to the tank. So if there is say a blocked fuel filter, what will this do to the operation of the fuel pump. On the carby TP, the fuel pump has a discharge orifice inside the fuel tank . This limits the pump discharge pressure, but with EFI the pressures are higher. This is simple to check the fuel pump pressure in the fuel gallery.
The clicking implies something but I'm not sure what. If you do any electrical tests, I suggest you use an analog voltmeter. Digital voltmeters have too slow a response to tell you anything useful.
I always reckon on a good diagnosis before spending money. But I wouldnt be swapping ECUs yet. Nor would I be running the fuel pump from an external battery just yet. I think I'd be checking fuel pressure first.
I have the manual so will have a look.

Thanks for your reply and your time, Rumpfy. The problem is solved (well, partly)

It was the ECU. I swapped the one in from my car and it works perfectly. The two ECUs have different numbers - the faulty one is a AW329505 and the good one is a AW319647. Interestingly, the faulty one looks pristine inside - no visible problems with the capacitors - but I'll have an electronic guru mate have a play with it.

The good one from my car looks like crap inside. It has an aftermarket sticker on the outside and there are very ugly looking solder blobs around the capacitors, seemingly a repair to tracks in the PCB.
For now, my car is off the road. We'll get the troubled car in for its Roadworthy and see if it is possible to get the bad ECU repaired.

My mate had a look at the ECU last night. There was no obvious problem like a bulging top to capacitors or liquid oozing but he removed the bigger cap and sent some pictures.

http://pic100.picturetrail.com/VOL405/8230927/24634276/411722938.jpg

He had to dig into the resin to repair a track on the underside. Here is how it is looking now after cleaning up ...

http://pic100.picturetrail.com/VOL405/8230927/24634276/411722937.jpg

He's off buying parts and is confident that all will be good. He wants to have a look at the other ECU - the one mentioned above that works but has dodgy solder blobs around the caps. I'm thinking it might be worthwhile getting him to look at the transmission 'puters in both vehicles too.

Ok, the repaired ECU came back. I fitted it in my car and the car runs great apart from a too low idle. Fault codes are normal (continual short on-off).
Starting from cold it holds near 1000 rpm but when warm it drops to 500 or 600 and will stall at the slightest provocation.
Note that the ECU from my car is in the other car that is about to be registered (it passed RWC yesterday). I don't want to swap back at the moment because the car will be going in for rego at Vicroads on Monday.

I've read somewhere here that it is a no-no to adjust the idle via the throttle stop. I don't know where to go from here. I've tried searching the forum and tried finding the relevant part in the PDF manual - bloody hard to find anything with so many pages to choose from and no linking from index. I am now getting a bit frustrated and am tempted to adjust the throttle stop. Can anyone please point me in the right direction?

Big smiles all round I guess.
Looks like the seal on the capacitor failed and spewed its contents. The capacitor contains an electrolyte which can boil off. Looks like the track is not burned by too much current but fried to current tracking through the electrolyte. This sort of fault could take a fuse cos it looks like the tracks are rather heavy in order to conduct a decent amount of current. Diode D3 in the pic has heavy gauge leads so looks like your fault is in some power handling/power distribution part of the unit.
Others would be better to comment on the idle speed. You have the manual and it may be there. In the electronics progression, the TR was still fairly simple. Electronics was logic gates rather than full blown microprocessors. It is possible that idle speed is set by a screw and adjusting it may be in order. With later cars like my TW, the idle speed is computer controlled and the system learns to adjust itself. Adjusting the screw in these cars makes a short term difference, but the system pulls the idle speed back to where the computer says it should be.
I drove a company TM (cracked block and failed auto trans), a TR, we have a 300,000Km TP carby, now used as a farm car, and a TW.
From memory, the only problem with the TR was it was a bit heavy on fuel. I thought the TM, when new, was better than my dads 230 E Benz.
regards and best wishes,

Thanks Rumpfy. Yes, big smiles (apart from the idle issue, which is a bit perilous - the car wants to die every time I slow towards a stop, so steering and braking is compromised).
I've been researching and found the best approach is to use google rather than the search function here. Finally found something that made sense and it was on this forum.

When the car was cold this morning it idled near 1000rpm, where normally on cold startup it would be up around 1300, then slowly come down to a bit under 1000. Apparently if I had left it to idle for 15 minutes the ECU would have adjusted the idle properly. Since I headed out for a drive within a couple of minutes it didn't have a chance to adjust properly. And since it is a warm day here and the car is sitting in the sun I won't have the opportunity until the morning. Wish me luck.

I've had a TN, a TS, another TS and two TRs - the last 3 costing less than $1000 each. I like Magnas a lot, but haven't had all that much to do with working on them. Now I'm retired so can't afford to throw money when things go wrong. This has been a useful learning experience.

I'll report back once the issue is solved. All the best.

If the throttle stop is set as it should be, I'd leave it and paitently work through other possibilities.

incorrect idle speed or ignition timing.

check fast idle air valve

test fuel pump el circuit, fuel pressure, injector circuit

spark plug, distributor, rotor crack, spark leads, clean wiring connection

air leak throttle body - flow meter, secure hoses, air intake resonance chamber for cracks

coolant temp sensor

idle switch

air temp sensor

air flow sensor

- associated wiring all round


gregorys makes a sec gen 4 cyl manual. if you can't find one you can have mine for 20 which includes postage. I don't have a scanner atm.

I had a chance to actually read the TR/TS manual I have. It is the Mitsubishi Workshop manual which I got from this site (I think). Certainly, I got it off the net. It is 1364 pages of gold mine stuff. The section you want is section 13 - 2. There is around 100 pages devoted to the fuel system for the ECI models.
The file size is 140 Mbyte which is a lot for me to send. You really need this manual. Please advise if you dont have it.
ts370000 is on the money as far as the items for checking go. The manual will tell you exactly what to do tho'.

If the throttle stop is set as it should be, I'd leave it and paitently work through other possibilities.

incorrect idle speed or ignition timing.

check fast idle air valve

test fuel pump el circuit, fuel pressure, injector circuit

spark plug, distributor, rotor crack, spark leads, clean wiring connection

air leak throttle body - flow meter, secure hoses, air intake resonance chamber for cracks

coolant temp sensor

idle switch

air temp sensor

air flow sensor

- associated wiring all round


gregorys makes a sec gen 4 cyl manual. if you can't find one you can have mine for 20 which includes postage. I don't have a scanner atm.

Thanks ts370000. That is a hell of a list, but I am learning just how complex these cars are, and how difficult it can be to chase a fault. I might take you up on the Gregory's Manual offer - I'll PM or email if so.

Rumpfy, thanks to you too. I do have the 1364 page PDF manual (see my second post). And I have now read right through chapter 13 and am experiencing some glimmerings of understanding. I guess I'm in denial about what needs to be done to check everything - but I'll get there if I have to.

At the moment the ECUs are not in their original vehicles - they are swapped and the '93 car has the '92 ECU working perfectly and all buttoned up. The important thing is to get the '93 car through rego on Monday, then I'll swap the ECUs back into their correct vehicles and address what I find then. I'll know more on Tuesday. Thanks again.

sorry for not rereading your 2nd post where you say you have 1364 pages.
In conjunction with your electronic mate, I think you are well on your way, and our work is done.

Bigger smiles now. The originally troubled car was registered yesterday and today I returned the ECUs to their respective places in the correct vehicles and all buttoned up. Both cars are working perfectly (well, as perfectly as a twenty-something year old Magna can).

Now is probably a good time to 'fess up that I have sent two second gen Magnas off to the crusher in the last five years without bothering to pull the ECUs. Yes, I am kicking myself all around the place. Now that I know where the little buggers are hidden so I won't be letting that happen again. I dropped in to our local wreckers (in Wodonga) to ask if they had any Magnas. Bloke said "Nah" and then asked what I was after. When I told him I was after a spare ECU he laughed, saying that they were sold within hours and there was nothing else of value in those cars.

Thanks guys. I'll be back.