All the sudden lately my car is running leaner than usual except under full boost(which it sputters and cuts from rpms 4300-5300). but if i go thru the rpms 3/4 throttle it never cuts but at around 7 psi my a:r's are 14.4ish instead of the usual 12's. and now when im in vaccum around -10- -20 accelerating my a:r's are in the mid 16's instead of usual 14's. its like i got a whole new tune to be lean. im picking up a new dizzy next week hopefully and hopefully that cures the poblem. whats it sound like to you?

fyi this is on a z6 with y8 head.

 

If your dizzy was bad I would think you would be overly rich from lack of spark, which in turn would mean more unburnt fuel reaching your wideband.

I would lean toward a fuel delivery problem. Perhaps your fuel filter needs changed, are you losing any fuel pressure at all. Maybe your fuel pump is on it's last leg?

 

check to see if you have any exhaust leaks before the wideband.

 

no, no leak before the wideband. its possible that my fuel pump is going bad yes. but i just changed the fuel filter a lil while ago and when it cuts, the a:r's on the wideband dont go lean liek its losing fuel. i really think its something to do with timing/ignition. and i can feel when i shift under normal driving that it is laggy/weaker than normal too and thats when its reading the lean conditions...

 

Is your ECu triggering some sort of fuel cut? Do you have any cels? Perhaps your chip is lose in the socket?

 

change the dizzy.i was having hte same issues two weeks ago. thanks to some guys here from H-t who said it was a dizzy problem i got it fixed. dont try to repair your old dizzy get a new one. and new plugs too

 

thats good news. yea im gonna hopefully get a new dizzy this week. today i was at a stop light and all the sudden my a:r's went from the normal 12's(which is ot good) but they went to 17's and my car started kinda popping and idling funny. then at the next light it was normal??

 

well. i put new bkre7's gapped to .28. stock plug wires, new cap and rotor, and walbro 255. still cuts exactly the same.... going to try a dizzy this weekend. i heard that cx or dx obd-1 dizzys will bolt on y8 head and work fine. anyone know if this is true?

 

bump someone please help....

 

i wanna know also i think i might be having the same prob

 

if you are having a missfire, your wideband will show lean, o2 sensors do not pick up liquid fuel dumped in the exhaust.

 

hmm. i wonder why i woudl expirience this cut right around when vtec engages to like 6000rpms. then it goes away after thaat and pulls like normal. but yet the a:r's stay in the 11's

 

any help would be awesome!!