3/4 cylinders

[Mark4g63t]

Well on my way home from work my car started to sound like a Subaru and lost all power. Pulled into a BP and it died and wouldn't start again. Got it towed home and pulled the plugs and #3 looked like sh*t.
It's greenish in color and looks like it has a tack weld on it/ melted electrode.
Coil pack tested good the primary ignition coil in the diagram tested at 1.01 ohms so it's a little high, says 0.77-0.95 ohms.

 

[GRAVEDIGGER]

I'd throw some new plugs in there and give it a go if it were mine. What else can you do? That's the quickest, easiest, and cheapest thing to do. The coil resistance is close enough. I don't think that's the problem.

 

[Mark4g63t]

Going to be doing a compression test tonight to see if it could be a piston ring. But with it not smoking i'm not sure if that's it. I will also try a different set of plugs. Seemed worse than just plugs tho.

Anything else I should check while i'm at it?

 

[AWDtalontsi96]

what plugs are you running?

Also all signs point to the cylinder running hot aka lean. Hows your injectors?

 

[BogusSVO]

Look down the spark plug hole, and have a buddy roll the engine over as you try to get a peek.

Check for a blown out intake gasket, or missing manifold bolt.

 

[boost97gst]

Thats lean for sure. Clean injectors asap and do as bogus said(hes usually right ). Im struggling w a similar problem but not near that lean. I may just check my intake mani gasket too.....

 

[Mark4g63t]

well compression test results are #1 162 #2 158 #3 0 #4 149..going to pull the valve cover tomorrow morning and see if any rockers fell off and also look to see how the valves look.

injectors have less than 600 miles on them..

looking like a bent valve.

Going to be pulling the head tonight/ tomorrow.

 

[Mark4g63t]

Pulled the head. Exhaust valve has a chunk missing. So Taking the valves out tomorrow and taking the head to the machine shop to have it hot tanked and to make sure the valve guides are still good.

 

[AWDtalontsi96]

Pulled the head. Exhaust valve has a chunk missing. So Taking the valves out tomorrow and taking the head to the machine shop to have it hot tanked and to make sure the valve guides are still good.

post picture of the messed up valve. Sounds like that cylinder ran super hot and it could of caused the valve to break like that. Stock valves? Stock cams? Stock springs? Hows your tune?

 

[Mark4g63t]

Here's the valve. Yes it is a stock head. Valve is not bent at all just missing that little piece. Bores still have crosshatching. Found a good deal on a set of Jackson Auto Machine STD size valves to replace them with.

 

[Mark4g63t]

Just dropped the head off at the machine shop. Will update once they call me with an update. I will also be dropping my injectors off to be flow tested/ cleaned. If the injectors turn out to be fine what should I be looking for as a cause.

 

[boost97gst]

Ring wiring back to resistor pack and the other side straight to the ecu. You should see maybe 1ohm, maybe less. If they ring true and 1 injector is not firing as much fuel and you dont have a clogged injector then youre probably looking at an ecu driver. One of the FETs or transistors is not pulling to ground properly or for the right duration leading to a narrow pulse width( leaner).

Ive got to get some free time and im popping my ecu open to replace the transistors and put some fresh heatsink on them. I have not heard of anyone DIYing this so im gonna wing it. I work on electronics for a living , as long as i can get to it i have a shot. Sucks not having schematics. Im sure T Dorris does and maybe the AEM guys DO have it but i havent found schematics online and dont think people would be willing to release hard earned knowledge like that.\