24.57 MPG, how is this possible???

[FestYboy]

new block B6, good head, stock 1.3 cam and intake, full exhaust. that's what i have for an engine. I used to get 35-37mpg but these last 2 tanks have been 24-25mpg and i havn't changed my driving style. any ideas would be appreciated.

Arty

[Guest]

are you saying the setup you are running now was 35+ or since the b6 swap it's gone down?

[Glitch]

You could start with a quick plug check. Tan good. Black no good.

[Gforcefd]

Well are you using the B6 ecu? That will be one problem. Also how long since you changed your air filter, fuel filter. Gasoline changes its chemical composition for winter months. So we use more in the winter, I mean worse gas mileage too.

Logan

[Tom]

The timing is critical on the B6 and probably the stock motor.

I was getting about the same mileage with a B6 as you are, about 26MPG and re-adjusted the timing and got 36MPG

[Damkid]

when i had a b6 in my car i was getting terrible milage, it was out of an 88 so the harness was different, so any connectors that were different i changed the parts for the b3 ones, injectors, distributer etc. i had the b6 MAF and ECU and it was running very rich, i have a feeling it was because of the b3 injectors, but i didn't feel like screwing with it trying to find the problem so i just put the b3 back in.

i'm not sure if this will be what you're looking for but i hope it helps

[Guest]

^^That's what I was getting at guys.. The B6 with the B3 intake (b3 injectors) and b3 ecu makes for really bad gas mileage. It runs real rich.. I ran mine that way for about a month before I swapped to the B6 intake (b6 injectors) which helped but it was still running rich. Once I went to the B6 ecu, I was back to 37-40.

[FestYboy]

ok sorry to dissapoint but I'm running a B3 Carb intake... it's an 88 festy. before i sawpped in the B6 i was getting 42 mpg average, and after the swap i was getting 36. now i'm getting 24, this is not a good thing.

and on top of everything, my oil pressure light came on solid tonight on the way home. it's been intermitant the past week, but now it's on solid. do the switches have a tendancy to go bad, or have i dropped the pickup tube?

[FestYboy]

while i'm at it on questions, about 2 weeks ago the festy died, wound up being a dead coil (2 years old). after i replaced it, i've noticed that i can't rev past 6000 rpm anymore. i used to be able to rev past 8 if i wanted to. any ideas?

note, this is a carbed B6 in an '88 festy

[Gforcefd]

I don't know how you got the festy to rev past 8 if it has a ecu, because of the rev limiter on it, but if its carbed, not that many of us have much experience in a carb'ed festiva it seems

[FestYboy]

bump

[gtd2000]

<----This one here gets 24mpg (ave) since 16,000 miles (1998) - totally reliable, no dirty plugs, runs at factory settings according to computer check...


Go figure..... :shock:

[5.0zone]

FestYboy, The only things I could think of are the air filter being clogged up or the choke is not releasing or the float/needle valve in the carb is not working as it should and is letting in too much gas. You should be able to check the 1st two fairly easily.

[FestYboy]

air filter is less than 10K old, but i'll check it again anyway. question: If the choke was not working properly, wouldn't i have idle and start-up issues??

And i did find a massive vac leak at the distro diaphram, so i have both lines plugged and i have a sneeking suspision that there's another one somewhere. when i plugged those 2 lines, i got an improovement in milage but not near what it was getting before. i'm going to replace the distro with the original one and see what happens , and i'm going to see if i can smoke test the vac line system today. will post results when possible.

[festivaWES]

This why i hate messing with carb cars...vacuum lines and carbs are a PITA