Blown motor tell what you guys think!

[Army248]

So i pulled out about 3/4 throttle and the car just shut off and now will only turn over but will not start. So I got it towed home and did a compression test and it reads as follows
cylinder 1 125
cylinder 2 80
cylinder 3 40
cylinder 4 130

Mods consist of full straight 3in exhaust no cats, 3in down pipe, ingine short ram intake, 3in turbo inlet, hks bov, cobb access port, denzo one step colder plugs, and fmic

I know the next question will what you have no internals? I do not as for fuel was between 1600-1800 wot
Let me know if you have any ideas or guidance thanks btw no CELs either

 

[MSMS3]

Doing a compression check on a cold engine (no choice since it will not start) is inaccurate. But your numbers are so low that you obviously have severe issues. Try testing again after squirting a little oil in each cylinder, and pull all plugs when testing so the engine turns over easily. If pressure goes up, you have cylinder wear or worn rings.

You are probably going to need to pull the cylinder head and inspect cylinders from above and may have to remove pan and do a rebuild. Those pressures are terrible. On a warm engine you should be seeing in the range of 160-180.

 

[Army248]

Hey thanks for the help

 

[Army248]

Anybody know what could have caused this by chance?

 

[MSMS3]

Got any recent AP logs you could share? Closest in time to the boom event. I'd like to see a short (no more than 30 second) MAF cal type log and a WOT pull from 3,000 to 6,000+ rpm. Very close to boom event.

I'd also like to see close up photos of the spark plugs and know how many miles you have on the engine, what AP map you are running, when you installed AP in relationship to your other mods (ie., did the AP come before or after the catless exhaust mods, etc.

And about that 3 inch turbo inlet. I'm curious. How did you connect the 3 inch inlet to the MAF and intake? Are your SRI and MAF housing 3 inch piping? Have you properly done a MAF cal for that setup? Just a few questions that might help us figure out what happened. Usually these things, particularly low compression, are cumulative things gradually working over time. But now you have a sudden and abrupt engine failure. Diagnosis now is probably going to be by examination of internals for wear or failure, along with analysis of the most recent data logs.

 

[Army248]

I do not happen have any logs . The 3 in turbo inlet goes to an ingine sri and yes its all 3 iN. I was running a stage 2 93 oct tune with ingine intake, tip,dp, and fmic with a 3500k 2 step .the tune was there before the tip and dp. Also it states to have fuel pump internals which I don't have . As for the plugs they where completely black toward the bottom and the 3rd cylinder had oil on it as well .Basically I want to know what need to be done to make it never happen again.

 

[MSMS3]

Need pix and logs. AP stage 2 and no logs? Can't possibly know how to prevent recurrence without knowing why the failure happened. What was mileage on the engine? Ever did a compression check before failure? Maybe just a high mileage tired engine too weak to reliably function at stage 2 boost and fueling level on a tired stock high pressure pump. Only takes a tiny fraction of a second fuel pressure dip under max load to go lean and blow, even on a healthy engine. You'd never see that dip in pressure real time, but a log would show it. Just guessing without more data.