I tweeked my UTEC all weekend. Got it running good. The cold start problems fixed. All my logs showed 0 knock with afr right at 11.25:1.
I went out this morning for a run thru all the gears.
Pulled strong right to redline in 1st-4th. Once I shifted into 5th about 120mph, it started loosing power and I felt it missing, that's when I noticed my EGT gauge maxed out, passed 1600F!
I imediately pushed in the clutch and took out of gear, and it died.
After I stopped I checked under car and under hood, no oil, it was full of water, (water temp gauge was normal).
I let it sit a few minutes, tried to start, it turned a bit then stopped, every try after, just clicking, (battery is good).
I think something in my fuel system stopped working or my timing advanced, I'm not sure.
My buddy towed me home. I also tried to see if it would turn over in gear by pulling it; no chance.
I'll pull the plugs and try to turn over by hand, if it won't I'll have to pull the head.
I still don't know why it would lean out like that?
Anyways IT SUCKS!
On the bright side, now I have a reason to build that stroker!

 

Uhm, I've had my car at 2,000 degrees EGT during a 160mph run, and it's never seized. Are you sure your AFR is 11.25 in 5th gear? I maxed out the stock injectors on 4th gear redline with 22psi of boost.

 

I have 680cc injectors. Walbro pump.

 

Did you pull the plugs and try turning it over by hand?

 

what kind of injectors? thats scary !

Sorry to hear about that,hopefully its not as bad as we think...

 

Well, hopefully its not too bad... but it sounds like you might have lost an injector or maybe pump pressure.. I guess we'll have to wait for you to try to crank the engine without the plugs and see.. at 2000 degrees you run the risk of melting things, but you could also have lost an injector or something and locked the engine, you'll know when you pull the plugs. It could be something simple..

 

check the vaccume lines around the Fuel pressure regulator.....if one of them popped off through increased boost-(cold out) then your engine could have gone super lean and....

I am seeing this fault happen increasingly on the dyno, fortunately I am able to see this happening when it occurs and I have enough time to abort the run...

Make sure allvacume lines are zip tied onto the intake manifold especially if you are increasing boost pressure
My 2c

 

Definitely bad! pilled plugs, all indicated lean conditions, #3 completely melted, #4 mostly melted.
Engine won't turn all way around, someting hitting (pretty sure in #3 cyl).
It will turn about 350deg, just won't let #3 come to TDC, probably melted pieces.
I looked into clyders with flashlight. #1,2 some some scorthing, no melting, #3 has obvious melted areas and little impressions were the spark plugs piece were flying around, #4 just shows a few impressions.
I can only see about a 1.5" diameter of the center of the pistons.
Now I need to figure out why I went super lean.
Here's what I'm considering:
1. Fuel pump went
2. Injectors went, (low possiblity of mulitple injector going though)
3. I just swithed over to OLF, so maybe my injectors had problems with the UTEC drivers. I have DSM 680cc made by PTE.
4. MY UTEC F-up.
5. Clogged fuel line/filter.
6. I already checked all vac lines, they are attached and seem fine.

It ran fine to redline 1st-4th, when I shifted into 5th, it lost power and started missing, EGT went off the scale, pushed in clutch, engine died.

Check these plugs out.

 

Bishiboy, sorry to see this as you have been playing with your Utec trying to iron out your power. Damn i wonder what went wrong here. It looks like a bad injector or your fuel pump went south.

 

holy crap. Thats scary. Glad I went 750 for the extra headroom. I guess it doesnt make any difference if they are not scaled properly. What do your logs look like? Do you have the runs you made while tuning the UTEC? You should post them so we can see. Thats wierd though if you tuned it for 11.25:1. Maybe your pump went bad. My walbro died and I needed to replace it. Shoot wish you had that log when things went South but I'm sure you werent expecting that. I guess I'll need to check my plugs weekly just to make sure things are copesetic.

 

This is VERY good advice. I have personally seen this happen to a buddys AWD Talon, and caused him to run lean and Boom cylinder 2 went in his car.

 

Yeah, I have also seen that happen on someones car, I have also seen the fuel pump output drop (the High/Low??) and cause a problem..

Since everything was ok as your rowing through the gears, when you hit 5th you had a problem, the best thing I can figure is you lost fuel pressure, or lost fuel volume and the pressure dropped off.

you can have the injectors tested, but like you said its unlikely you'd have failure in two injectors at the same time.

The only other thing I can think of is in 5th you could have ended up in a completely different load column that wasn't tuned.. Most of us would not normally be able to do a full load run through 5th with full logging to be certain everything was working ok at 100+ MPH

What really concerns me is that it apparently happened so quickly, is it possible something happened to it earlier and it just let go on that run?

There's no question something failed, now you just have to figure out why.

 

Did you ever change those injectors?

 

sorry bro....now you can build the engine...damn...sorry again...

 

BTW man - sorry to hear a stand up guy like yourself is having these kind of problems