yesterday about 630 pm driving in second gear, about 3/4 throttle. no boost spike, car bogs alittle then all of a sudden the engine dies...I was able to pull over and try and start the car once again....I have a real hard time starting the car and seems as if theres no compression. I finally got the car started and now the car sounds like a Suby. I managed to drive the car down the street to my tuners shop. He first checked the spark plugs and found that cylinder # 4 spark plug was bent alittle, then compression checked all the cylinders and found that cylinder #4 compression was lower than the rest. Funny thing is that the car doesnt emit smoke out of the exhaust and after everything was put back together we fired it up and ran normal... the head/motor will be taken apart tomorrow to see the extent of the damage. I hope and pray that its not going to be an engine re-build...lmk what yall think

Dyno tuned on Wednesday...358.66 hp 360.02 tq (11.5 AFR)

MODS:
AEM EMS
AEM 5 bar map sensor
AEM AIT sensor
MAP downpipe with external dump
GSC S1 cams
850cc clinics
Walbro 255
ETS 3.5" intercooler
Muse upper and lower I/C pipping
HKS titanium exhaust
3" piping not cat
Megan manifold
Stock IX turbo
Apexi boost soenoid
K&N cone filter
NGK Iridium 1 step colder plugs
Gates racing timing belt

 

sorry to hear that.. post pics when tore down

 

what gas were you tuned on, boost level?

Nothing in your mod list jumps out to say there is a problem. I question the need of the EMS on your setup, also the amount of torque you are making on a 9 turbo is WAY high.

 

What he said, what fuel/boost level? Got a dyno chart? Boost plot? Miles on the engine?

And why in the world did you go to AEM? The stock ECU/MAF setup will take you all the way into the 600 awhp range without issue.

 

Leakdown test? It's probably not a piston failure if it's not smoking/ chugging oil. I'm going to guess that it bent a valve becuase of a botched cam install or a money shift which resulted in a massive over-rev. Makes sence why the spark plug was jacked up too.

Tear it apart and update the thread.

 

It was tuned on 92 octane @ 21 psi AFR 11.5

 

92 octane 11.5afr? Should shoot for 10.9

 

i would have to think that you have a bent valve, but check the top of the piston, if it hit the plug then it might have hit the valves

 

It seems tuned fine for 92 and the boost level. You'd be amazed at what AFR these cars like and how it varies with mods.

How much lower was the compression in that one cylinder? I wonder if it has a sensor issue, it sounds like it had been flooded out and lost a hole and then came back as it cleaned out. A hurt motor with a dead hole doesnt "heal" itself with a sparkplug change. Something else had happened.

 

burnt exhaust valve?

 

That would be my guess if it stayed a dead hole.

You said it started running normally again though? Washed down cylinder with a stuck ring could do the same thing.

 

Damn i hope i dont have to re do the bottom end

 

I'd take a look at that Walbro 255. Could have started to loose fuel pressure during that pull causing knock then eventually the Walbro went out.

 

well the cars if finally up and running, turned out to be a lifted head....Shouldve put in the ARP headstuds while the cams were getting installed. Basically #4 piston was cracked at the top edge, and second of all the two corner head bolts were loose. We sent the head and block out for honing and machening. The pistons, rings, and bearings were all changed in all cylinders, and we also went and changed the manifold to a Buschur and the stock 9 turbo to a green...Going back on the dyno soon and ill will post the new chart as soon as the motor is ready to be ABUSED!!!!LOL
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that suck! but now you will have a nice engine. GL.