| Author |
Message |
Michael Hutton
Tinkerer
SA
soarer v8 limited
Posts: 20
Reg: 01-2006
|
Hey guys, was driving my car, and all of a sudden dropped to nearly zero power, and the light for overheating cats came on - pulled over and nearly the whole exhaust is glowing red! Drives like an absolute pig, would anyone have any idea what could be wrong? Would it be that both cats have failed at the same time? The exhaust has just been replaced from the first Y join back with a 2.5 inch, which has subsequently been cut off, to no avail. Any Ideas? Cheers |
Andrew Ferres
TryHard
WA
'86 Cressida V8, '84 Soarer V8, '90 C-F Celsior V8
Posts: 442
Reg: 07-2005
|
One of your ignitors/coils/coil leads/dizzys/rotors has failed.
Car is now running on 4cyls, with 4 cyls worth of raw fuel being pumped into the exhaust, and exploding in the exhaust manifold, hence the superheated cats.
You just need to find out which of the above has failed. |
Daniel Clarke
DieHard
NSW
TT 2.5L 6 cylinder
Posts: 717
Reg: 03-2006
|
COil Pack dead. Will send all unburnt fuel down the exhaust system which will ignite from the heat of the exhaust and melt the internals of the cat.
http://soarercentral.com/sc-forum/messages/51876/77299.html?1151911647
Here is a similar thread. |
Michael Hutton
Tinkerer
SA
soarer v8 limited
Posts: 21
Reg: 01-2006
|
Thanks guys for being so quick to reply. I'll let my mechanic know, and keep you posted. It's such a great community on here when everyone is so willing to help out |
Daniel Clarke
DieHard
NSW
TT 2.5L 6 cylinder
Posts: 719
Reg: 03-2006
|
MIchael Keep in mind You will Probably have to replace the Cat that has been damaged. Always do this AFTER you have fixed the problem |
Andrew Ferres
TryHard
WA
'86 Cressida V8, '84 Soarer V8, '90 C-F Celsior V8
Posts: 443
Reg: 07-2005
|
Depends how long he drove it for.
I drove my car for about 5-7mins with the cats glowing, and then a couple of days later for 3-4mins.
Cats are still fine today.
But yes, they do begin to melt when they get mucho hot |
Don Bagnall
Moderator
New Zealand
I have WAY less Soarers than Hayden :-(
Posts: 4897
Reg: 05-2005
|
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Daniel Clarke
DieHard
NSW
TT 2.5L 6 cylinder
Posts: 720
Reg: 03-2006
|
Hahaha. CLassic DON |
Anish Varsani
TryHard
QLD
V8 UZZ30
Posts: 431
Reg: 07-2005
|
Why bother replacing the cats if you don't get an error code? |
Andrew Ferres
TryHard
WA
'86 Cressida V8, '84 Soarer V8, '90 C-F Celsior V8
Posts: 444
Reg: 07-2005
|
The cat overheat light will come on when the cats overheat (der) and glow red hot.
Once they cool down, they may or may not have suffered damage.
If they have suffered damage (ie, started to melt/collapse), it may not be enough to cause them to heat up, but it may be enough to cause a loss in power. |
Daniel Clarke
DieHard
NSW
TT 2.5L 6 cylinder
Posts: 725
Reg: 03-2006
|
If they have been RED hot and partially collapsed and blocked, Once they cool down they will stay that way BUT may not get hot enough to throw a code. BUT will block/restrict exhaust flow to the point that your lacking power. |
Anish Varsani
TryHard
QLD
V8 UZZ30
Posts: 434
Reg: 07-2005
|
hit the cat core with an oxy torch!! Easy way to get a free flowing cat or lack there of!!
The rear "O2" sensor must be a pyrometer if it's going to throw a code on overheat. |
Andrew Ferres
TryHard
WA
'86 Cressida V8, '84 Soarer V8, '90 C-F Celsior V8
Posts: 445
Reg: 07-2005
|
The rear o2 sensor gets confused with US Spec SC400, which actually have 4 o2 sensors.
But yes, Jap Spec stuff is a heat sensor of sorts.
Japs have been using them since they started using cats. |
Michael Hutton
Tinkerer
SA
soarer v8 limited
Posts: 22
Reg: 01-2006
|
Hmmm, I think it may be a good idea to get some nice big cats then he he he. |
Don Bagnall
Moderator
New Zealand
I have WAY less Soarers than Hayden :-(
Posts: 4925
Reg: 05-2005
|
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Michael Hutton
Tinkerer
SA
soarer v8 limited
Posts: 23
Reg: 01-2006
|
Well, turns out it was neither the igniter nor the coils - the mechanic has tracked someone down with diagnostic gear, so hopefully we can get to the bottom of this - 3 weeks driving a yaris and a matiz!!!!! Depressing! |
Daniel Clarke
DieHard
NSW
TT 2.5L 6 cylinder
Posts: 804
Reg: 03-2006
|
Ecu? |
Don Bagnall
Moderator
New Zealand
I have WAY less Soarers than Hayden :-(
Posts: 4984
Reg: 05-2005
|
Emu? |
Michael Hutton
Tinkerer
SA
soarer v8 limited
Posts: 24
Reg: 01-2006
|
well, 4 weeks now, and still nothing - diagnostics gear was put on and came up with nothing. Any ideas at all? Mechanic is still testing, but if I could help him out |
Harry Lemmens
TryHard
Victoria
V8
Posts: 238
Reg: 11-2004
|
It usually is a blocked Catalytic converter. Generally caused by the failure of one of the two coil packs.
It has been known that a good cleanup of the coil wire into the coil "fixes" some coil issues. Otherwise, need to replace the offending coil.
Might pay to open the distributors and look for signs of distress on the caps and the rotor buttons.(Arcing, cracks, carbon tracking) A good mechanic should have done all of these things already.
... other things to check: Check that each of the injectors is still intact. If one managed to fail OPEN, it will be pumping lots of unburnt fuel down through the exhaust. Would have said though that 7 cylinders normally wouldn't make it a pig. (Noticable, but not especially so)
Did the mechanic actually check the cats ... and the exhaust system behind the cats? The matrix in the cats can melt down, blocking either the cats, the pipes after the cats, or even the mufflers
The best test for an exhaust blockage is disconnect both cats and take the (very loud) car for a quick spin around the block ...
The coils can be tested for fruity sparks at turn-over of the engine. (Careful, the shock from these would be considerable)
Injectors may require removal to be tested. Test is relatively easy, but ask again if you need a procedure ...
ECU reset might not be a bad idea ... (disconnect the car battery for 10 seconds) |
Neil Griffiths
Trader
NSW
212Kw @ 8psi MANUAL Super Charged UZZ31
Posts: 3005
Reg: 07-2005
|
Also, inside the ECU on the TOP board ( First one that flips over after unscrewing ) you will see a single CAP marked C507, this cap is starting to leak and kill the ignition system..TOTAL stop and no restart of the engine is the end result.
Check it for leaks around it..
I would advise EVERYONE to check this cap before it drops it's guts. easier to replace while good.
I have attended to 2 of these so far..
( Same problem is starting in the JZA70 ECU ) had one the other day, so this may also progress over to the JZZ30 ECU. |
Michael Hutton
Tinkerer
SA
soarer v8 limited
Posts: 25
Reg: 01-2006
|
Cheers guys, I will get him to have a look at these - it's muchly appreciated, I'm sure you're all aware of how frustrating these things are |
Adam Parisi
Tinkerer
SA
UZZ30
Posts: 36
Reg: 07-2005
|
Same thing just happened to me when I was leaving work. I don't know exactly what has gone (I'm hoping it's just the cats have gone), but it's going to be a good excuse to get a new exhaust system and headers. I'm kinda annoyed that this happened to me just two weeks after I had to get a new alternator and get the power steering pump rebuilt though  |
Mark Paddick
Goo Roo
ACT
UZZ31 V8 Soarer , JZZ30 TT Soarer
Posts: 2842
Reg: 07-2005
|
I've done about 50 of 'em.
The fault is not always the same as it is not actually the faulty capacitor that is the problem but is the fact that it has spilled its' guts over the ROM chip and possibly even eaten through a couple of surrounding PCB tracks. Replacing the capacitor without fixing the collateral damage will not fix the ECU.
An ECU in this state will not always give an error code (most likely not). Sometimes you will get the code for a faulty airflow meter. I have never seen a case where the airflow meter was faulty when the ECU said it was; it was always the leaky cap fault. Conversely I have never seen a faulty airflow meter actually generate an airflow meter alarm. I now treat an airflow meter alarm as a faulty ECU and so far that has always been correct. (of course now that it is in print the rules will change.... ) |
Neil Griffiths
Trader
NSW
212Kw @ 8psi MANUAL Super Charged UZZ31
Posts: 3011
Reg: 07-2005
|
Oh...Missing under light load up hills and some throttle applications will be the Air Flow Meter |
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