10-11 mpg!! Help
Thread Starter
TECH Apprentice
Joined: May 2015
Posts: 367
Likes: 5
From: connecticut
10-11 mpg!! Help Okay so I have gone on two 150 mile trips....when I get back I full up and I also fill up before I leave, so I know how much gas I'm going through, and I'm constantly getting about 11mpg...what the hell is going on! Car was an auto, swapped it and tuned it....honestly can't tell u what I was getting for fuel milage before because I was running the auto in 3rd only (all gears fried) other than the swap and headers and a Cai and 56mm throttle body...cars stock, oh and lt headers and straight pipes....cat starts hard, as in I believe my fuel pressure regulator is going out. Gotta prime it twice or else it cranks for 5 to 10 seconds....other than that car runs good I believe....just absolutely GUZZLING fuel....I see others getting 20mpg and I'm like **** thats great! But this is hurting my wallet so anyone got any ideas?
Thread Starter
TECH Apprentice
Joined: May 2015
Posts: 367
Likes: 5
From: connecticut
Oh yeah, car has 2.73s in the back so I cruise at 75 at 1500 rpms...constantly shitting to 5th to go uphill so I'm not lugging the engine....5th at 75 is about 2k....any ideas would b great
TECH Addict
Joined: Dec 2010
Posts: 2,610
Likes: 4
From: Maricopa, AZ
You're probably running pig rich from the open headers. That gives the O2s a false lean condition. Put in the rest of the exhaust.
EDIT: I see you're running straight pipes, so cancel my comment. Lol
Got a data log?
EDIT: I see you're running straight pipes, so cancel my comment. Lol
Got a data log?
Thread Starter
TECH Apprentice
Joined: May 2015
Posts: 367
Likes: 5
From: connecticut
No I don't have a data log....I can make one thogh....should I do to and from work, idling? What do u think? And yeah I got exhaust all the way back, just no cat or muffler...how long of a datalog?
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Thread Starter
TECH Apprentice
Joined: May 2015
Posts: 367
Likes: 5
From: connecticut
Yeah as far as I know one on the block Is gage, waterpump is pcm....come to think of it I broke off the head off the connecter on the wp, so it's just two metal prongs that I put the plug on.....that could really cause all this!! Seems so small to b my problem lol
Thread Starter
TECH Apprentice
Joined: May 2015
Posts: 367
Likes: 5
From: connecticut
okay im trying to upload these datalogs......its not letting me.....how do i do it? trying to use the paperclip in the toolbar. also realized my afr goes from 14ish to 18ish when i turn the ac on.....seems a bit excessive...also swapped my coolant sensor on the waterpump. didnt notice the coolant codes come up again.....my sensor was definetly broken though, the plug spun on the actuall sensor so even if that wasnt my issue, needed to b replaced reguardless
TECH Addict
Joined: Dec 2010
Posts: 2,610
Likes: 4
From: Maricopa, AZ
okay im trying to upload these datalogs......its not letting me.....how do i do it? trying to use the paperclip in the toolbar. also realized my afr goes from 14ish to 18ish when i turn the ac on.....seems a bit excessive...also swapped my coolant sensor on the waterpump. didnt notice the coolant codes come up again.....my sensor was definetly broken though, the plug spun on the actuall sensor so even if that wasnt my issue, needed to b replaced reguardless
Thread Starter
TECH Apprentice
Joined: May 2015
Posts: 367
Likes: 5
From: connecticut
Well now you guys r gonna think I'm dumb....today I had an epiphany, my speedo is off cause I did t56 swap...tried to tune for 2.73 and 6spd but didn't work but tuned for 4.10 and 6spd and it worked so my speedo is off by 1.5 times. As in speedo says 40, I'm doin 60, 30=45 20=30 so on and so forth, just realized that messes up my milage so on my 160 mile trip, I really went 240miles, which i 18 mpg about....not too bad....alot better than I thought
