Author Topic: Really bad mileage  (Read 2764 times)

SiGmA_X

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Really bad mileage
« on: May 22, 2011, 07:27:05 PM »
Evening 42ers! I just finished up a motor replacement in my gf's 318i and its getting horrid mileage. ~17mpg over 5 tanks, mpg=miles/gallons of course. The car is not entirely smooth at idle. Nearly, but not fully.

New parts:
*All timing chain components - M20 fly so used an indicator + cam blocks to set timing
*COP Conversion (new coils)
*Plugs
*O2
*Air filter
*Dyno oil (first oil change on new to us motor, will go to synthetic shortly)
*Deleted TB heater BS

Unrelated:
*All gaskets minus HG
*WP/Tstat
*M20 clutch/fly (Maybe cause of issues?)
*Compression is all even at 220psi/cyl

I scoped all sensors, everything looked good - The O2 was a bit lazy at around 800ms so I replaced it, but the new one is not really any better.... Weird its not <500ms like normal.. And nor is the MPG. So looks like I have an almost-new O2 FS...

Any input would rock, I'm getting fed up with this 4 cylinder lol. Shoulda done an M50 swap, better MPG and more power/reliability/cheaper!! :mad:

Thanks much
Roman
93 325iS - Stock
86 325e - Stocker than Stock

DesktopDave

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Really bad mileage
« Reply #1 on: May 23, 2011, 07:17:04 AM »
Sorry you're having trouble, you should be seeing mid-20s in town, mid 30's highway.  I'd check for a stuck fuel injector.  With the TB hose delete you should have a rock-solid idle.

Maybe do a Mustang 19# swap?
'08 Karmesinrot 128i 6MT
'86 Zinnoberrot 635CSi (M30B32/G265/3.46 torsen LSD)

Sold: '97 Montrealblau 318iS, '91 Brilliantrot 318i, '91 Brilliantrot 318iS

SiGmA_X

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Really bad mileage
« Reply #2 on: May 23, 2011, 09:21:00 AM »
You read my mind Dave! I'm bidding on some Ford/Bosch yellow tops, but not the skinny type that doesn't clip in. Super sketchy that so many people are using injectors that do not mount properly.. I have had properly mounted properly shaped injectors pop out on my e36 before due to weak clips, and a bent/not seated clip is sure to come out...

Anyway, glad to see injectors were on your mind too! Thanks sir.
93 325iS - Stock
86 325e - Stocker than Stock

nomade30

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Really bad mileage
« Reply #3 on: May 24, 2011, 12:44:21 AM »
I would say pull out the spark plugs to see how rich you are burning.

Just for reference the P/N of the injectors you are looking for is F2TE-A3A
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SiGmA_X

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Really bad mileage
« Reply #4 on: May 24, 2011, 12:54:34 AM »
They aren't fouled/don't appear to be excessively rich. Rather odd.

Thanks for the PN. What I was going to buy is 0280150556 which according to MotorMan is a cross reference for the F2TE-A3A. Excellent!
93 325iS - Stock
86 325e - Stocker than Stock