4AGE - Help Needed

[L4AGZE]

Ok this one has really got me puzzled. I have got a Corolla GTi UK spec standard car never been modified and the problem i have with it is it wont start unless it is rolled and i know its not the actual starter motor.

When the car is stationary and you try to start it the engine does try to turn over but doesnt. I have changed the spark plug leads the dizzy cap and rotor blade. Plus also swapped over the igniter and it is fine.

The problem seems to be with the spark. When i have tested for spark there is no spark. However the car will start everytime when it is rolled.

I cant figure out what the problem is and how it is possible for the car to start ona bump when there is no spark?

Any ideas or where do i next need to look?

[TRD-12A]

so it winds over very slowly or not at all??

[frostyadonis]

Ok this one has really got me puzzled. I have got a Corolla GTi UK spec standard car never been modified and the problem i have with it is it wont start unless it is rolled and i know its not the actual starter motor.

When the car is stationary and you try to start it the engine does try to turn over but doesnt

The problem seems to be with the spark. When i have tested for spark there is no spark.

1. battery condition?, does this still happends when you use jumper leads with another vehicle.
2. how did you check for spark if it won't turn over?
3. starter motor. have you checked for excessive voltage drop?
4. what is the alternator charge rate
5. the 4a engines usually turn over easily, even with a semi flat battery...

[L4AGZE]

1. battery condition?, does this still happends when you use jumper leads with another vehicle.
2. how did you check for spark if it won't turn over?
3. starter motor. have you checked for excessive voltage drop?
4. what is the alternator charge rate
5. the 4a engines usually turn over easily, even with a semi flat battery...

When cranking it doesnt wind up slowly it is as normal.

1. Battery is new so no problems there.
2. Cranked engine with spark plug lead off with a screwdriver pushed into the lead to see the spark.
3. When you say excessive voltage drop do you mean from the battery?
4. If you mean the charge rate when the engine is running will check this again. The dial on the dashboard looks ok though but will put a meter on it.
5. I know thats what makes it even more frustrating

One last thing this doesnt happen every single time every now and again the car will start but it is the exception. Sometimes you can get a few starts out of it but will start everytime off a bump.

[frostyadonis]

One last thing this doesnt happen every single time every now and again the car will start but it is the exception. Sometimes you can get a few starts out of it but will start everytime off a bump.

the symptoms point to a starter motor on the way out
but before you wrote that it can't be the starter
my question to you is why can't it be a faulty starter?

if it was an ignition fault the engine should not run at all even when roll starting...

also before you wrote "won't turn over" but later you said "turns over fine but won"t start"
wich one is correct?
when to fault happens what is the state of engine cranking speed?
any funny noises or intermitted cranking?

[L4AGZE]

the symptoms point to a starter motor on the way out
but before you wrote that it can't be the starter
my question to you is why can't it be a faulty starter?

if it was an ignition fault the engine should not run at all even when roll starting...

also before you wrote "won't turn over" but later you said "turns over fine but won"t start"
wich one is correct?
when to fault happens what is the state of engine cranking speed?
any funny noises or intermitted cranking?

Ok i think something has been lost in translation when i said it "wont turn over" and "turns over fine but wont start" i was referring to the state of the engine cranking speed which is fine. The engine cranks fine but wont start.

There are no funny noises or intermittent cranking.

The reason why i dont see why it could be the starter is i have had the starter out and it works fine when you wire it up to a battery. Also because we dont seem to get spark. Now is the car sparking reliant on the starter motor? I dont think it is hence why i discounted the starter. I will check the bvoltage again when cranking and see if this throws up anything. Funny thing is the car started this morning but i bet it doesnt later!

[frostyadonis]

yes. thats right. starter motors will continue working until they fall apart.

there is no relation from the starter motor to the no spark problem unless the starter is turning the engine over too slowly under load (as i was refering to earlier about checking the voltage drop at the battery whilst at start position)

if the engine is turning over at normal speeds the first item i'd check/replace is the ignition coil and also ignition switch

when is the fault occurring, hot or cold starts?

[bazzery]

Have you checked the earthing strap to the engine? We had an issue with starting and it was that bad every now and then the car would run rough. Cleaned up the earthing points and tightened them up and got a good spark back.

[L4AGZE]

Well turned the engine to start and checked the voltage at the battery it was 12 volts checked while cranking it dropped a bit to about 10 volts which seems fine. Car didnt start.

It does it both on hot and cold starts.

I have swapped over the coil and coil lead and problem still occured.

Havent tried ignition switch or checked the earth strap so will try those and let you know how i get on.

Thanks for all the advice so far. As you can see its a nightmare of a problem or an interesting one depending how far you are along with it!

[RA35GT]

Hey dood,

Have you checked to make sure you have ignition power (to coils/igniters etc) in the start position?

I'm assuming all is well in the ignition position because it rolls starts fine.

[L4AGZE]

Hey dood,

Have you checked to make sure you have ignition power (to coils/igniters etc) in the start position?

I'm assuming all is well in the ignition position because it rolls starts fine.

Ok bit of an update.

Swapped the ignition switch over from a running car made no difference and also used a jump lead on the negative terminal of the battery to give a stronger earth connection.

Still no joy with it.

I havent checked to make sure there is ignition power to the coils/igniters in the start position. Whats the easiest way to do this?

Other than checking this i am well and truly stuck.....

[neal]

You will need someone to give you a hand, while he or she cranks the engine you check the voltage at the ignitor/coils.

I think 7M-GTE MX73 is on the right track. Check/test your starting circuit.

[L4AGZE]

You will need someone to give you a hand, while he or she cranks the engine you check the voltage at the ignitor/coils.

I think 7M-GTE MX73 is on the right track. Check/test your starting circuit.

Ok what voltage should i expect? Same as starter motor 12 volts?

[RA35GT]

You should get battery voltage dood. so around 12v or so.

(P.S. you can disconnect the small starter wire when doing the test so your not turning the engine)

[35rolla]

man when you check power at coil on cranking use the engine as an earth point, if its got good signal try body as earth point. if you see a difference you have a bad engine earth strap. earths get overlooked to often and cause bullshit problems. i'd personally use a test light as you can see voltage drop as the light goes dim. sounds more to me like you lose power to the coil on cranking or your starter motor is drawing to much current, you will still get good cranking but there's not enough current left for much else. one other thing is on the australian built ones there is an earth for the dizzy on the inlet manifold and it gave me much pain back in the day. older cars have two terminals on the starter, one for crank signal and one to supply 12 volts for coil on cranking. your starter may have it. and one more thing i'd do is run a wire from positive terminal on your battery to the coil posiutive and try cranking it then is it starts then you have found your problem or ruled something out if it does not. i know its a bit long winded but i hope it helps.