I was running low on gas this morning..
so i put some on the 87 octane
i usually pump only 91 octane(just cuz)
but ***** getting expensive
and since reading so much that the octane readings really didnt matter unless you tuned the car
i pumped 87
and now my car wont pass 4k rpms
feels like thats the rev limit
and i started throwing out a lil bit of white smoke from exhaust
i never had this problem till i pumped that gas

any ideas on what it can be?
thanks

B20v motor
b20b bottom end b16 head
stock internals

 

Check engine light on? Sounds like the ECU is in "limp home mode" to me...

 

is your speedometer working?

 

my check engine was on..
i check the code and it threw out code 10
thats the iat sensor
it was disconnected a while ago because the wire was too short for my intake

i got it connected again..reset ecu
it doesnt redline at 4k anymore
but it does feel like its bogging out once i try to press the gas pedal further down

speedometer is working but i notice it bounces a lil more than usual
ive had trouble with it in the past but all i did was connect back snug

ive leaning towards the dizzy or tps
since i am running a LS dizzy on my pr3 head
some shop ****ed me over by givin me an ls dizzy...im going to switch it sometime this week since i finally have the money to replace it
but i havent had any problems till i switched from 91 to 87 octane

Any other suggestions?
thanks btw

 

The octane will affect the "feeling" of your engine. It may be detonating and if you wired in a knock sensor with an ECU that uses it, it may be pulling timing. Are you running a tuned ECU?

 

I feel as if the detonation in the combustion chamber is detonating on its own and not by the spark plugs..

im currently running a p28 chipped
i dont think p28s read knock sensors..or do they?
i think my LS had one tapped in there before so i used that one
not 100% sure tho

 

Just Went outside to look for a knock sensor
and yes i think ive got it...

correct me if im wrong
next to the alternator bracket by the oil filter is 2 sensors
i think 1 is the KS and the other is oil pressure?

 

Just an update
Through some octance booster in there and let it run for a little while
(So that the booster can sit thru the gas)

Drove it around and it feels great..
So I guess octane readings do really matter
Never pumping that ever again
Thanks for your help

 

Good news - and no, the P28 does not support a knock sensor.

 

P28 doesn't support KS? I'm assuming if you have some sort of engine management like s300 or Neptune that the knock sensor input is added in provided you have a knock sensor?

 

P28's do no support a KS - period. For that you need a P30, P72 or PR3

 

Limp mode