spitefulcheerio

iTrader: (1)

...okay so normally this would be cool because all the #vapelife bros would become my nut swingers buuuuut I'd like to get my car up and running again. Here's the rundown:

Car is a S4 TII with a JDM S5 swap currently running on the S4 ecu, all the emissions deleted. Was coming home last wednesday, had a little fun with a ecoboost mustang. They're easy kills. Anyway, had a decent hesitation in 5th so I let off and hit my off ramp. Figured the car needed plugs. Car is running fine afterwards, still has all its power. Gave it some gas through a couple gears and it felt 100% normal. As I was getting close to my house, I was slowing down to make a turn, downshifted, and car started sounding like a subaru. Now this wasn't a crazy downshift; it was maybe up to 3.5k but the loss of power was very obvious and it basically wanted to shake itself apart at idle when I pulled over to the side of the road. Limped it home under 15 mph for half a mile, parked it, and started ordering ****.

Got a working, used, leading and trailing coil and new plugs. Put everything in today aaaaaaand same thing. Tested the wires with one of those "non-destructive" spark testers and it lights up on all 4 wires so I know I'm getting spark. Wires are those red ones and they look good. Pretty sure they were done last year before I bought the car. Plugs looked like **** but premix life soi expected it. The owner of Pettit was just telling me a few months ago how strong my motor felt. Never had any issues with cold starts, sometimes hot starts can be a bitch if it was like 5 minutes after turning the car off but I'm new to rotaries and I've had multiple rotary guys get my car hot started without issue...apparently I hold the key for too long. Idk. I've listened to videos of blown apex seals and they seem to be running way smoother than my car with an obvious miss every third. My car little sounds like it's struggling to catch its breath.

So I just checked all the vacuum lines and couplers in the area between the turbo and intercooler. I have an aftermarket top mount but the car was running fine with it for weeks and ive had a boost leak on the car before...it wouldnt hold idle at all when it had that issue. Now the car will hold idle no problem, it just runs like absolute ****. Checked the hose under the boost sensor too and it looks fine. Rad is full to the brim, it's a fluidine unit, never overheated. I'm stumped. Stuck fuel injector? Blown motor? Boost sensor? Blown motor? CAS? Blown motor?

Who's taking bets that it's a blown motor? Doing an old school compression test sometime this week.

insightful

#needsanewengine

compression test

spitefulcheerio

iTrader: (1)

**** me. Zero compression strokes on rear rotor.

its66

iTrader: (2)

dislike......

blck

Sad to hear about the compression! Rebuild it now with a decent street port! oh and get a FCD if you dont have one!

lduley

iTrader: (1)

Do not get a FCD, that is/was a horrible invention that still added to blown engines

blck

what would you use as a preventative anti fuel cut for over boosting then? Just curious!

insightful

yeah, perfect way to blow another engine.

i'm not sure you understand how a FCD works, the title of the Fuel Cut Defenser is misleading and a misnomer. it in fact just tricks the ECU to thinking the boost is lower, allowing it to advance timing further than it would at the same boost level without an FCD and push out more boost BEFORE fuel cutting. how would one go about better boost cut prevention? leave the car stock or omit the stock engine controls and go with a aftermarket standalone that you can set boost cut at that cuts spark or fuel to both rotors instead of just one. yes, the stock system only cuts fuel to the rear rotor under boost cut, which is why the rear rotor usually goes bye bye, the rear rotor also runs hotter than the front rotor so it inherently will detonate easier. yes it was a flaw with mazda engineering but it still beats putting on a tampering device that makes the problem even WORSE.

if you must use an FCD, you should retard ignition timing by at least 5 degrees to offset the timing curve issue in boost. low end performance will suffer, but it still beats walking home.

blck

Well good thing i don't have one on my car and plan on running a haltech, was only suggesting on my friends success and other members on the site. But if you insist, yes, he is right. Stand alone is the absolute, very best option.

Also, do you have any forums or post that may give me further insight on other misleading bad things i may not know about?

insightful

this site has plenty of tips, but it requires a little digging for answers.

in fact just about all my collective knowledge is already on this site, but i blocked my old account to get some peace and to move on.

spitefulcheerio

iTrader: (1)

Don't worry, no FCD going on this car. That is and always will be terrible.

Car already had some good stuff done to it and will be getting a basic blueprinted streetport rebuild with all the fixins like water pump, e-fan, belts, etc, etc. BNR s1 turbo will go on after after motor is broken in.