Hi everyone,

I'm new here, I've got an issue with my TR Magna (Auto) I bought a couple of weeks ago.

Basically when I'm driving and the revs are around 2,500-3000 my car starts jolting and the acceleration is all jerky, it's very noticeable when O/D is off but when it's on I barely notice it due to the revs being lower. I took it to the mechanic and he plugged the diagnostic machine in and showed me how all the readings were going up and down (coolant temp, e.t.c e.t.c) and he thinks the ECU is to blame for the acceleration issues with it running rough.

Has anyone come across this issue?

Also the mechanic suggested I take the car to an auto electrician which I'm doing tomorrow.

That is a misfire.

Spark plugs, ignition leads, distributor coil, power transistor, distributor cap, Hall sensors in distributor, ECU. Not to mention the plug on the distributor.

Check the simple and cheap stuff first, don't replace the ECU on a mere suspicion.

How is the mechanic reading the ECU?

PS. I'm assuming your car is a 4 cylinder with EFI, because a carby car doesn't have an ECU! lol

has the engine light come on yet

the diagnostic plug is near the drivers fuse box

engine light- faults
MODELS APPLICABLE: TR / TS verada
DIFFICULTY: easy
TOOLS NEEDED: led tester
ITEMS NEEDED:
EXTRA INFORMATION:
What the the engine symbol light indicates when it comes on

1. Engine control unit
* 2. Oxygen sensor
3. Air-flow sensor
4. Intake air temperature sensor
5. Throttle position sensor
6. Engine coolant temperature sensor
7. Crank angle sensor
8. Top dead centre sensor
9. Knock sensor
10. Ignition timing adjustment signal
11. Injector
Caution: - The engine warning lamp also comes on when the terminal for ignition timing adjustment is
earthed during ignition timing adjustment.
*Note - The 0' sensor on 4 cylinder models built after February 1992 does not activate the engine
warning lamp

How is the mechanic reading the ECU?

PS. I'm assuming your car is a 4 cylinder with EFI, because a carby car doesn't have an ECU! lol

Yeah it's the EFI model, should of added that my mistake. He was just using a scanner that he plugged in under the fuse box.

I've replaced the leads, the spark plugs look fine but I'll replace them too. I'll see what the auto electrician says about the ecu.

Thanks for the help so far guys. I'll report back.

Ok so I've replaced the leads, spark plugs, distributor cap looks good. What else should I do? It's still misfiring :-( If I go to the wreckers and get the exact same ECU and put it in will it work? I was going to get it looked over today by the auto electrician but he wanted $100 to look at it.

Yep, well . . . .
I had a TS 4 cylinder with a no-start problem, everyone told me it was ECU .
Took it in to a crowd (need to look up name and address) who tested the ECU. It was ok, they told me to bring in the distributor and coil/transistor, turned out it was a cooked coil. $85 for the testing and $90 for a new coil and it sprang to life.

To be honest, and not picking on you, etc, but you and your mechanic have gone "ECU is dead" without clear empirical evidence, and gone down that road. If the car is running at all, the ECU should be fine.
Could be a costly waste of time replacing it.

Get the ECU checked out, or start by following the code reading procedure above.

Automotive Service Solutions
65A Grange Road
Welland 5007

08 8241-7555
email matt@efi.com.au

This info is a few years old, I hope they are still in business. Their website is still up, but the phone number is different.

Once you know the ECU/distributor/coil is ok, you can start looking at fuel - fuel filter, pump, for example.

Thanks for your help, I'm not going to replace any more parts till I actually find what is going on. I can't find where to buy an led tester from, any ideas?

electrical hobby stores used to have them dick smith tandy or similar

look for 12 volt ones on ebay

or get a multi meter

Ok thanks, how do I read the error codes with a multi meter?

its better with the led light because it just flashes

the led read out on the multi meter readings go high low

its a lot harder but sometimes .. you have to work with what you got

Ok thanks, I bought an led light from Jaycar. Which pin is the one I put the tester in? I know it's the plug on the driver's side though.

hang on the engine light flashes on the V6
page 112 on a gregories for the 4 cyl

11 ox sensor
12 air flow
13 air intake temp
14 TPS
21 collant temp
22 crank angle
23 TDC sensor
24 vehicle speed
25 atmospheric pressure
31 knock
36 ignition timing
41 fuel injectors

looking at the diagnostic plug
bottom right is number one thats the positve
top left is number 12 that is negative

to clear codes at end of repairs disconnect battery terminals for 20 seconds

so the gregories says

I'll give it a try now, thanks.

Not sure why but the led isnt flashing I plugged it in right. Where should I have the clip at the end of the tester wire, do I have to ground it somewhere else on the car?

is the ignition on

says here the engine check light should flash for five seconds

then try the led light ??

just going by the repair manual

one long pulse then four short makes it 14 does that make sense ?

one long pulse then four short makes it 14 does that make sense ?

Yeah ignition is on, there's no light or pulse, should i put the crocodile clip on some metal on the car?

going back two steps

turn ign on check light must come on for 5 sec
if lamp stays on check wiring between dash ecu terminal b14 for short to earth

so you want to check if terminal 1 is power i guess put the negitave lead of led to the chassis as an earth
just checks the led tester is working
doesnt say not to

terminal 12 should be earth
so the wire at the end of the tester should go there
to give you the flashes

So weird that this isn't working, could the diagnostic plug be broken? Is there any other way to test? Because I thought it might of been the tester but I tried it on the other parts of of the car and the bulb lit up.

the plug /wires to it could be broken ..no there isnt any other way of diagnosing
have had bad diagnostic plugs

has to be an earth wire and a positve to make circuit within that plug
you may have to go to an auto electrician just to test/fix that plug

without some guide from the codes you have to start tossing new parts
at the engine bay till you find the faulty part/s

start with all the connections in the engine by look for corrosion
make sure all are clean and in tight

could be one or more things on that fault list

Good news :happy: I replaced the ecu with one I got from the wreckers, I pulled it out of a TR that only had 140,000 kms and prayed that it would work. The ecu cost me $44 + 1 month warranty.

Now the car runs great! No misfires and there is more power also :woot:.
Thanks MadMax and magna buff for your help it has been appreciated!

OnYa! Another second gen rescued from the brink! lol