Help with grenaded 1jz

xsjado

Engine bling!
Jul 15, 2007
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Melbourne
Just posted this up on sf.com.au and thought I would post it up here too.

Sadly on Friday I was having my car dyno tuned with an SAFC-II. Got a call from the mechanics tell me that my engine decided to kick the bucket. Story goes that they started the run, got to about 4000rpm and had a bad sounding backfire followed by white smoke. They cut the ignition and let the wheels come to a rest, they then started up the car again with a slight knock, then the revs picked up along with really back knocking. I'm not sure how much of this is truth, they said there was no indications that the engine was in bad shape and wanted to shit itself.

By the time I got in there on Saturday they had drained all the oil to check for anything in the oil, so they conveniently couldn't start the car so I could hear it first hand, so all I could get was the dyno printouts, now I don't exactly know if what I am looking at is good or bad. So I'm assuming it is bad. I have no idea what was done between the 2 runs on the SAFC-II, but it made a huge difference, they think that on the death run it was well on its way to 225-230rwkw. The blue run was the run before the engine gave way and red was the death run.

p942963_1.jpg


p942963_2.jpg


Didn't have printouts with RPM, if its any help it was all done in 4th gear and it has a 4.56lsd behind it.

Also I am wondering where I stand here with what I can do about it. I never signed any paperwork saying that I take full responsibility if anything happens to the car. Now I knew that if anything happened to it that it would be money out of my pocket, but I believe that they where to blame for the engine failure and should come to some sort of agreement. I have already purchased a new 1jz so do you think it is fair for me to demand $0 labor for them to change the engine, or fork out the costs of labor for another workshop. I don't think they could fuck up too much while changing engines so I just want it done and get my car out of there.

Ninja edit: forgot to mention, engine had 12x,xxx km on it.
 

Freshmaker

New Member
Feb 3, 2007
396
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Oconomowoc, Wi
I am no expert tuner, but I'm pretty sure running your car WOT at above ~14 AFR will kill an engine.

My guess: They were trying to bring that 80-100kph AFR up a little and messed it up big time.

edit: its in kph not mph :)
 

xsjado

Engine bling!
Jul 15, 2007
252
0
16
36
Melbourne
IJ.;942986 said:
My eyes thank you!

Not seeing anything really strange apart from the rich spike at 105 kph and the lean spike at 115 (he might have stabbed the pedal there).

I'm getting mixed answers here. Have someone on msn telling me that the blue run ran way to lean and the lean spike in run 2 was possibly too much for the engine to handle.
 

IJ.

Grumpy Old Man
Mar 30, 2005
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Fresh: Don't know what you're looking at but it's nowhere near 14 afr?

Jado: I wouldn't expect the 13.5 on the blue run to have hurt it that badly though.
(what RPM @ 100 kph?)
 

Freshmaker

New Member
Feb 3, 2007
396
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Oconomowoc, Wi
xsjado;942991 said:
I'm getting mixed answers here. Have someone on msn telling me that the blue run ran way to lean and the lean spike in run 2 was possibly too much for the engine to handle.

14.7 AFR is stoich and ~12-12.6 AFR is a common place to tune for. The blue run looks a tad lean, but it wasn't bad.

Now the second run is up above 16 AFR. That is the area I was talking about.
 

xsjado

Engine bling!
Jul 15, 2007
252
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16
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Melbourne
So basically I was just unlucky and got a dud engine or a combination of bad luck and a bad tune? Seems a bit odd as it never missed a beat and had been running fine up until the attempted tune. I am looking a buying another 1jz with approx 90xxx km's on it that came from a Chaser. Had a compression test and came back with 170, 170, 170, 175, 175, 180. The engine has apparently been sitting for a while and once it has been run in for a bit it should bump back up to around 180psi.
 

IJ.

Grumpy Old Man
Mar 30, 2005
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I'd like to see what's failed before passing judgement

If you had full logging on the run it'd be easier to see what went on but without a TPS trace I don't know if the wave is a tuning issue or he was moving the throttle.
 

xsjado

Engine bling!
Jul 15, 2007
252
0
16
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Melbourne
Fair enough, as you can tell I am a little bit edgy having this happen and looking to blame anyone for it :(. All I know is no matter what, I don't plan on going back there.
 

IJ.

Grumpy Old Man
Mar 30, 2005
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If they weren't on/off the throttle they should have buttoned off and checked the tune then run it up again.

There's a lot of cowboys that once a pull starts they just keep the boot in....

I had an injector lay down and the operator didn't shut it down ... result: Hole torched through piston.
 

Dirgle

Conjurer of Boost
Mar 30, 2005
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Pauma Valley, CA
Lambda is showing 17:1 AFR's, and the manifold is seeing ~3psi, not a healthy way to start a run. and it's referenced on the dyno sheet by the low power of the second run. The power doesn't pick back up until the AFR's come back under control. I'd be willing to bet if we could see knock and timming logs, it would show that timming was being pulled like crazy. A correlation to RPM would be nice. Unfortunately keyboard engine diagnostics is not an exact science, but either some one jacked up the safc tune, or you have a fuel delivery problem. but with how close the two runs were and the fact that the first run was clean, I'd guess a bad tune on the piggyback. Just a guess though with the information at hand. I'd also guess that when you do an engine tear down, you will find damage due to pre-ignition, not due to failure from normal wear and tear. For an engine to go down like that after a clean run previously usually has something to do with the tuning not the engine it's self.
 

IJ.

Grumpy Old Man
Mar 30, 2005
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I was ignoring the start of the red run as it's so far out I'd have expected them to abort if that was a power run without on/off the throttle...

Wasn't there and don't know the shop but as I said there are a lot of Cowboys here :(
(not enough data to say without stripping the motor)
 

xsjado

Engine bling!
Jul 15, 2007
252
0
16
36
Melbourne
IJ.;943088 said:
I was ignoring the start of the red run as it's so far out I'd have expected them to abort if that was a power run without on/off the throttle...

Wasn't there and don't know the shop but as I said there are a lot of Cowboys here :(

Well they are predominately a v8 shop (nothing against that :biglaugh:)and they got the dyno about 1 month ago. So I think the whole Cowboy theory could be quite possible.