MV dropping

jshot

Active Member
My o2 Mv are dropping at top of 3'rd gear at WOT. I increased the fuel at WOT on the TT chip and this did bring the number up across the board but again drop at top of 3'rd gear and knock knock who's there. running 18PSI 94octane.

I am going to investigate fuel pressure? maybe alternator voltage to the hotwire kit?

anything else I should track down?
 
not sure the air temp under the hood but outside temp 70-75 deg
Okay, so you haven't been out in cold Ontario weather. You'll need to verify fuel pressure is rising 1 to 1 with boost. Alternator could be failing as well. Let the engine get up to operating temperature in Park and post your Scanmaster numbers. BLM counts could be high meaning you have a vacuum or pre turbo exhaust leak.
 
Time sitting in the alcohol laced gasoline would be a way bigger factor than the miles driven imo
Are you logging or at least looking at the fuel pressure as you are creating the boost?
 
Okay, so you haven't been out in cold Ontario weather. You'll need to verify fuel pressure is rising 1 to 1 with boost. Alternator could be failing as well. Let the engine get up to operating temperature in Park and post your Scanmaster numbers. BLM counts could be high meaning you have a vacuum or pre turbo exhaust leak.
I am in ontario. this was occurring at the end of the season. all number were good. i don't have a record of them. BLM i believe was 124
 
Time sitting in the alcohol laced gasoline would be a way bigger factor than the miles driven imo
Are you logging or at least looking at the fuel pressure as you are creating the boost?
I Believe i do have a log. i will try and find it. this was a few months ago before winter. i was not able to track fuel pressure at the time.
 
I changed the fuel pump in my car every spring. It's a 2 beer job and I'm pretty sure it's cheaper than head gaskets. And Jack at Racetronix in Scarborough can have a pump to us in 24 hours.
 
Op.. Suggest you follow up on the questions being posted.
No point in playing "20 Questions" when asking for help.
 
Rich asked you how old the pump is. So how old is it? At 18 PSI on pump gas you're pushing it. If that pump starts to weaken in the slightest you'll start seeing KR.
i haven't checked flooding yet, I live near the river. it gets pretty scary at times

I was not able to find a log

i would say the pump is 6-8 years old.
 
6-8 years old. When you get off the phone with Jack from ordering a new fuel pump it's 37F today. Go fire it up to operating temperature and give us the SM numbers in Park.
 
6-8 years old. When you get off the phone with Jack from ordering a new fuel pump it's 37F today. Go fire it up to operating temperature and give us the SM numbers in Park
maf=6
lv8=41
volts13.3
int=131
int=124
blm=123
coolant temp 163
air temp. 38.4
rmp=800
tps=0.40
iac=28
02cc=cycling up
 
When you did the last wot blast did the maf max out to the 258? I wouldn't go doing any blasts and you probably can't with the weather up there but maybe check an old log.
 
When you did the last wot blast did the maf max out to the 258? I wouldn't go doing any blasts and you probably can't with the weather up there but maybe check an old log.
i cant recall. my memory fails me these days
 
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