so i have progressively had a problem worsen on me.

my evo 8 had the rpms drooping and almost dying everytime i put the car in neutral rolling up to a stop.

then overtime it became worse and started dying everytime i rolled up to a light unless i featherred the throttle a bit.

which then turned to the worst...

i took my car out for a cruise and it was running kinda crappy and wasnt putting out the usual power it makes, i raced a bike and i put the car in neutral coming to a stop, car shut off and wouldnt restart for an hour.

i got the car home running without a maf (it was the only way itd start)

so far ive changed the spark plugs which helped alot, (the car once again starts and idles fine but as soon as i start driving it within 4 blocks itll die rolling up to a stop sign again)

it idles at the correct afr but the plugs i just put in it are already completely black after driving tops 2 miles.

the injectors make a weird zzzz zzzz zzzz noise instead of the usual tick.

ive changed coil packs, fuel rails, FPR, checked all connections, checked the IAC, new maf, new plugs, reset computer, no i havent boost leak tested it yet but all the piping is secure, i dont think it would be the TB or intake gasket cuz i completely blew those a year ago and the car still ran without them sealed.

im really running out of ideas. my friend had basically the same problem that he never solved just pulled out the motor but they had changed ecu's and injectors on his car and nothing changed, i know that shouldnt eliminate me from changing them as a possible problem but i was somewhat trying what they had not to start with.

possibly an electrical problem? or TPS? some relay? the car is 100% mechanically sound. it starts right up and idles perfectly fine for atleast 20 minutes thats the longest ive left it idling its just as soon as you start to drive it has full power for about a block and then starts losing power and eventually bogs out, as if the car is just loading up on fuel and it wont restart first crank until it sits for hours.

any ideas? and yes i have searched around and i have had 2 master mechanics along with everyone i know whos had an evo look at it, i work on the cars everyday of my life at work and have never had this problem come up before.

thanks in advance to any advice or help

 

Well my initial thought was your IAC but after reading through the rest ...I'm not sure anymore. How did you check the IAC (take it out but leave it plugged in and turn the key to start without cranking?)?

Do a boost leak test...wouldn't hurt to try and fix any leaks.

I assume you put your maf back in?

Are you throwing any codes?

Have you done anything to your evo recently?

Do you think it is going into LIMP mode when you describe it losing all power 2 blocks away?

Your spark plugs turning black so quickly is an issue as well........is it oil or carbon buildup?

 

yes i pulled it out and left it plugged in, the IAC responded correctly.

it throws no codes, yes the maf is back in.

not other than take out my tial and out a recirc tial in which i then removed the recirc so its just venting to atmosphere (which is what its tuned for on race gas 100oct)

the car limp'd once but the rest of the time it would use the full rpm range.

the plugs are charred black not from oil.

 

i have looked into the cylinders and there is no oil not to mention nothin else out fo the ordinary

 

ill be trailoring it home tonight, its currently sitting on my friends drive way so itll be boost leak tested tonight

 

is it possible that my fuel pump is going out and its throwing too much fuel? id think it would be the opposite tho

 

Well carbon on your spark plugs is due to oil in the combustion chamber (how much I don't know).

....so...maybe this could possibly be a head issue, head gasket, piston rings....I'm kinda talking out loud and typing this so bare with me....if head comes off have a shop check for leaks and warpage....

...black/charred plugs could also be your A/F ratio...running too rich.

Hope this helps you!

 

Not sure about your fuel pump....maybe someone else will chime in and answer that for you.

 

Do you have still have the stock cat? Have you done anything to it recently before this happened?

 

no cats, its a straight 3" all the way back.

so i got the car home and i boost leak tested it, ended up finding a hole in the hose w/ the restrictor coming off the j pipe. so i cut off enough to remove the hole and put the vacuum line back on with the restrictor. checked for more leaks and i dont hear any besides my boost leak tester itself >.<!!! lol so idk yet if its HOLDING pressure, i just dont hear anything else.

car will now start from hot and drives fine, wide open throttle no longer breaks up and it has all its power back its just still struggling when returning to idle, drops to about 500rpms struggles a little while the oil pressure icon flashes then returns to normal idle. when pushing the clutch in to move again itll go back to struggling at 500rpms but doesnt usually die (strange, idk why it does that everytime i push the clutch in after coming to a complete stop)

the car is once again driveable, id say dies 2 out of 10 times coming to a stop, drove it atleast 4 or 5 miles around the neighborhood.

what else could it possibly be? given the car does hold pressure, waiting for the epoxy to set on the boost leak tester -_- (at WOT it does hit 29-30psi then tapers)

 

I had the same issue which turned out to be the cam angle sensor.

 

I had same issue...TPS and Fuel Pump.

 

hmm the cam angle sensor is the last thing i messed with when i changed my cam seals (they were leaking mad oil)

i dont exactly remember if that is when this started happeneing or not tho hmmm

 

As I recall, it can be installed 180 out.

 

lol found my problem... spun a bearing in the block.. thats no good -_-