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Loss of power/engine died after giving it boost


SUPRA4EVA

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This is the first time I've had the car out in a while.

Driving around for 30 mins no problem, cursing along, giving it some boost here and there.

Then I saw a good inline stretch and put my foot down working from 2nd up to 3rd or 4th (5-6K range) when the car lost power and became sluggish.

The whole dash lit up, so I pulled over to have a look around.

Got the car started again, had a listen and a look under, all seemed okay but there was a flutter coming from under the middle of the car when revving the engine, like an exhaust leak...

The lights on dash when started were: yellow - oil level (which was fine) and yellow - rear light fault (my lights were dim on dash and rear ambers I was told) red triangle (this can be a bunch of things). Tank was 1/2 full.

But decided to take it easy and head back but not long after it started loosing power again, chugging along and dash lights getting dimmer and dimmer until there was some clicking around the dash (solenoids I presume) and the engine died.

Was not able to start it after but the starter did go.

Once recovery came the car was started but the lights mentioned above were still on so it got towed away to a garage.

The car has always been reliable and this is the first time this has happened. I know battery is over 10 years old and it discharges fast these days if you play round with lights/windows but it always had enough to start the engine as long as I kept it unplugged when not in use for a while. It was actually the next thing on my list to get this year.

Could the battery be a cause, could it affect the fuel pump or other electrics when ruining or even the alternator?

Car's all stock, that includes the turbo setup, only has an aftermarket cat back with the 1st cat still present.

This is all the info I have, I had no choice but to drop it off at a garage, I'd rather be looking at it myself but my hands are tied.

I don't know what the diag codes are.

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I'm no expert by any means but have you checked the battery and alternator are well? Those sound like an odd combination of lights and usually odd is grounds/battery power. 

My other thoughts run to the ECU being poorly, but that's probably a stretch and not something you can easily test for or do anything about. 

Do you know how to check the codes?

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"But decided to take it easy and head back but not long after it started loosing power again, chugging along and dash lights getting dimmer and dimmer until there was some clicking around the dash (solenoids I presume) and the engine died."

 

This defo sounds like alternator to me, the only time a Supra has left me waiting for an AA man I had the same, lights dimming and engine cut out, AA tested the alternator, kaput, popped a new battery in from his van and drove the over 10 miles back on that while he follow behind. Your battery history/fast drain could have been the alternator deteriorating  and not just the battery being old, it just might not have been getting much charge)

I personally would get a new battery, pop it on and if it starts then get a volt meter and check it reads somewhere near 14 volts (proves the alternator is charging).

 

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Thanks guys. I'd be all over it but as I have nowhere to work on it, it's still sitting at the garage that recovered the car.

Annoyingly the active spoiler ended up being in the down position and it was heartbreaking watching the winch cable pushing on it but it wasn't damaged.

I've never had to check fault codes yet but I believe it's like on the MR2 Mk2...paperclip and watch the blinks.

The alternator does sound plausible, it could have been overworked every time it had to change this battery up after long periods of no use.

PS are OEM alternators and batteries still available new?

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I decided to take back the car and wait until I can look at it myself, really not keen on someone else working on it.

A new battery was however fitted and it starts fine and drives but while running I still have the following lights - left to right:

Battery - red, Rear Lights - amber, Triangle - red, Brake System - red, Low Oil Level - amber.

I'll have to get the fault codes off it first thing and will be looking at changing the alternator as a new battery and it's discharging...

But all these dash lights on currently (especially lights, brakes, oil level) will they clear after the car is back to "normal operation"?

And I've definitely got a rattle from under where the prop shaft is when I rev the engine so that will need looking at too.

 

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Have you done as @Scootersuggests and stuck a multimeter on it to measure how many volts the cars pulling when not running vs when it is ?

That should give you a good indication as to whether the alternator is doing anything now you've swapped the battery.  You should see around 14v when its running. Let us know what numbers you get?

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99% the lights will go once a new alternator is fitted.

Reasonable ones on ebay, I'd just check the plastic connector is the same as yours and get one. You can probably get your original refurbished to rather than bin it.

 

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On 3/29/2024 at 12:39 PM, Probby said:

Have you done as @Scootersuggests and stuck a multimeter on it to measure how many volts the cars pulling when not running vs when it is ?

That should give you a good indication as to whether the alternator is doing anything now you've swapped the battery.  You should see around 14v when its running. Let us know what numbers you get?

Yeah I did and it was below 12V. It's out now, trying to get a new one.

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  • 2 months later...

So I got a new alternator fitted and all the lights on the dash went out when I started the engine and it all seemed good but once I measured the voltage across the battery it was reading below 12V...so the battery is still not being charged for some reason.

I looked at the 120A fuse but I can't tell if it's faulty, the wire looks solid, I do have a black wire loose in the fuse box though.

New alternator and battery but there's clearly something still wrong.

I will be doing some work on it soon so will investigate as I'll have access to tools but any suggestions?

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On 6/3/2024 at 3:57 PM, keron said:

mark the crank pulley too. if its split, it will also give the same undercharge symptoms..... that black wire in the pic is not factory either...

Pulley seems intact and the black wire was attached to the positive stud in the fuse box, so I removed it...maybe what remains of an old alarm?

Checked the battery again and it was charging this time, over 13V👍 ...so maybe it was a bad connection before.

But when I took it out I noticed the master warning light and rear tail fault light would flicker, when at lower speeds mainly, 40 and below iirc.

Thinking about the rear lights, I did swap out my uk spec to a jdm set and the rear tail fault light does come on during ignition, could that be the issue? Fuse is fine and all rear lights work.

Can a disabled active spoiler (via button on dash) cause any issues?

It drives fine but I'm quite jumpy after having it break down and when I saw the lights flicker I was panicking in case it breaks down again 🤪

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Moved the car somewhere else as I have some stuff to do and decided to double check the battery while running...it's below 12V again. It's not an earth either.

It was definitely showing 13V+ the other day so the alternator must be working at least some of the time if it was charging.

Electrics is not my strong point so trying to find what's causing this will be a pita.

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Yeah still not charging (pulley is intact and marked).

I no longer get a Battery light on the dash at all, nor the Engine light...and diagnostics doesn't work either.

I had a hand with a few checks (Ref 1995 Electrical book: Charging P68 and Power Source P56) to check the Alternator/Charging System fuses. 120V ALT, ALT-S, IGN, GAUGE all seen to get power too and really can't find much wrong there. The only other thing is to check is the 3-pin plug but the Alternator will need to be pulled out again to unplug it.

If the 3-pin plug is fine, could it possible be a bad alternator?

Also could someone post a photo of what lights are meant to show on the dash during ignition please?

PS what is a Combination Meter??

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  • 1 month later...

Anyone with electrical experience have any other suggestions on what could be causing:

1. The battery light not to coming on during ignition when alternator is installed/plugged in - light 100% works when tested w/o alternator installed.

2. Battery not charging when engine running - new alternator passed bench test...yet both the original and new alternators behave like this when installed.

Everything concerning the alternator loop, like fuses/wires all seem to be good, nothing looks out of the ordinary.

Could the immobilizer/aftermarket alarm be causing issues?

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If you can film the light sequence when you turn the key that would be handy. But I had a similar panic a couple of weeks ago and it was the ECU main harness plug not being seated correctly (I pushed in the plug but in my haste didn't pull the lever down) and the light sequence sounds familiar, no EML, no alternator light, but 'some' lights ... assuming this is all good you can check ECU fuses (I think it's powered by the main EFI fuses from memory so check all of those) after that it could well be an ECU problem (check you have ground and +12v (permanent/switched) when the ignition is on. 

Other thing could be a fault immobilser. Or grounds... it's always grounds 🙂 

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