So I filled up yesterday after beating on it to see if my code comes back, and no it does not come back. However mpg was all the way down to 15.3 mpg!!! Yes! The 7000# ram is still the mpg king of the household lol...

Is that a possible sign that the vacuum source to the FPR is broke or disconnected? It has been this way since the 17% pulley update.

Most if not all the miles on that tank were city/fun miles...

 

I think if the vacuum line to the FPR is broken the car would run lean, not rich. You should be able to see the vacuum line to the FPR without pulling the intercooler as they tend to crack right at the elbow that connects to the regulator. You can pull the intercooler to inspect the rest of the line, I changed mine out completely as it had a bunch of cracks.

As far as MPGs go, with my 15% pulley I get about 20-23 (depends on driving style) city and 30+ on highway runs (if careful).

 

Roger that... however I think the vacuum on the regulator is going to drop pressure not raise it. It should rise up to full pressure at any boost. a pressure gauge on the schrader port & a vacuum pump will tell for sure. I will get that and the vacuum pump in hand and pull it apart again for inspection.

 

I don’t have a Gen 1 but... Bypass valve not working properly? If the blower is always on boost, the ECU will by adding more fuel.

 

It was not and was tilted towards the open side making it laggy for boost. That has since been swapped. I will admit to having a heavy foot on this tank but 15 is kinda way low I think. I dont have solid mpg numbers with this car since it turned out to be so buggy after getting it. Now it appears to be solid except for low mpg. Gonna run thru half a tank and see where it really sits. It did get 2~3 tanks in the low 20's previously with the same type of driving.

Also, when I filled it up, dumped in half a can of sea foam into the fuel to try and clean the intake track in an effort to clean up the intake valves of any carbon deposits... no way of knowing if there are any but I do have comp numbers from a previous test. The plan there is to get the little woman to help me do a sea foam hot soak on it. Being that I forgot to add the vacuum line for the hot soak I have to pull it apart anyways and will check all the vacuum lines. The T I am going to add will be right next to the fpr.

So... gotta find the vacuum pump and ideally the fuel pressure gauge to check for fpr operation and to verify vacuum line integrity.

 

15mpg i don't think I've ever seen even on my heaviest footed drives....
sorry I didn't read more but any codes ? I would change your front 02 sensor , even just throw in an eBay cheapo ( im using one too) to see if it helps. My mileage was gradually going down too until i replaced the front 02 and it gained pep back and mileage.. but with that low of #s I would lean towards a bad fpr or a stuck open fuel injector
even with all my mods and a decently aggressive driving style , I still see 26mpg city and if the wind is favorable I can still see 35 on the freeway doing 80mph turning 3200rpm

 

Does anyone mod their Mini, drive it hard and actually expect good gas mileage?

 

lol well no...but in all fairness o.p is rite . These little things DO suck gas. My 97 modified hci ect 4.6l cougar got almost as good mileage as my cooper. Id get like 23/29 or so in that car AND it was auto so I wasn't able to neutral roll as much as I do.
I just think these engines aren't good mileage engines and is what it is..but o.p's mileage shouldn't be THAT low.

 

No I dont expect 30s for mpg and did not buy it to be a commuter... thats what the ram is for. My expectation is low 20's for mpg, 15 raises a flag. I've had tanks already in the mid 20's and that was behaving, mostly. Like I mentioned earlier, going to run a few hundred miles on it and see how it is doing. If it continues to drink excessively with me behaving then yeah something is definitely wrong. Made no progress on it this weekend (ram tuning).

 

I'm at 22mpg (or 9.4km per liter) with mine. Is purely driven for fun (no trackdays), no commuting etc. I always fill it with RON98 (E5).

15mpg sounds like massive overfueling indeed.

 

Yeah that seems a tad excessive... might as well have a v8 * all the that goes with it. Need to run out to a wrecking yard after work today and will drive it out there... its a good 40+ miles from home with minimal stops, should know by the end of the day if something is off.

And... thinking about it, at lunch I'll fire it up and use a spray bottle with water on it to see if I can detect a vacuum leak before I drive it.

 

17% pulley without a tune is a mistake, supercharger consumes more mechanical power, it produces more air but it is not used correctly, the combustion is defective, the advance values are not the correct ones, so a combination of factors that lead to a high fuel consumption.

 

Edit: Arent you the one who is using a LINK ECU and doing your own programming?

So your suggestion (indirectly) would be to go back to a 15% pulley until I get tuning in hand?

When I first got it back on the road the immediate gut feel was it was not as strong as it was with the 15% pulley. My thought was it had to do with the defective BPV. Now with the DT valve in there performance does not appear any different.

Can you explain your comment "the combustion is defective"? My expectation would be that more air (measured by the MAP sensor) leads to more fuel in an attempt to keep the AFR correct within its limits.

I still have not installed the RMW header, reading up there appears to mixed reviews on its effectiveness due to the bottleneck head thats on there. My thoughts there were to wrap it, install it, evaluate its performance and potentially add a plate at the exit to slow flow down a tad as needed until the head is "fixed" or replaced. As an example, if the exhaust diameter were 3" and OEM was 2.5", start with a 2.75" plate and move up towards 3" until desired performance is found. I did this with a V8 exhaust setup on a truck and was very happy with the results. it could be looked as fine tuning the exhaust IMO.

Also on the horizon is the JCW injector swap. Not looking to make a track car out of it, just get it so its performance is how I'd like it and learn more along the way.

 

Check out my thread on a Bosch Volvo injector (available via FCP Euro) swap before you spend big money on JCW injectors. My total cost for 380cc injectors was around $115, including injectors, o-rings and harnesses.

 

No , I'm not LINK ECU fan.
Now your supercharger produce too much air,you have high boost level, but ECU is calibrated for stock pulley,indeed Lambda sensor try to compensate, but can't do it more than plus or minus 10%,you run now with bad Short fuel trims, and that mean less power.When i say defective combustion, i mean lean mixture=danger of melted pistons,high EGT values.
I recommend 380cc injectors from Bosch , part number 0280156063, better pattern spray than Siemens JCW injectors, and are plug and play, no need adaptors.

 

Roger that, EGTs make sense from a lean condition. I buy what your saying and think I will swap back to the 15% until programming is in hand.

Its been reported that the 380cc injectors are a plug & play install w/o tuning... does it make sense going that route with the 17% pulley? More fuel to bring the AFR back in line...

 

No ,even 380cc injectors with 11% pulley from JCW need a tune,will get too much fuel with 380cc injectors ,exhaust gas will smell of unburned gasoline.

 

adrian,
Isn't it true that with the 380cc injectors that they run a lower duty cycle since the mixture is governed by the O2 sensors, thus needing a lower duty cycle to maintain the appropriate AFR and allowing more fuel to compensate for the increase in air volume from the underdrive pulley at WOT? This part of the feedback loop is one of the things that makes fuel injection so much better than carburation, on the fly AFR adjustment.

 

Somethings wrong.....I get around 25-28mpg mostly on the highway with my 03' JCW and a 17% pulley.

 

That's what I'm running......

 

It's only a 4cyl 1.6L motor making around 200hp......it shouldn't guzzle too much fuel, modded or not.

My 07' 335i is putting down around 480whp...and I can still get 25-28mpg on the highway, and around 20mpg around town if I don't beat on it that hard.

If you are making horrible MPG in your mini, something's wrong.

 

My 04 JCW with 17% SC pulley and 2% Damper pulley and 186 K miles on the clock routinely gets 29 to 32 MPG on 2 lane country roads in normal driving mode at normal speed limits.

 

Same here.

My AFR gauge is showing around 14.8-15.0 while cruising........ I'd be curious what kind of AFR's you guys who are getting horrible MPG are seeing. A slight rich tune can make a big difference in fuel MPG. I'm pretty lean at cruise, but get down into 11.1 at WOT which is a little on the rich side....and I'm still getting really good MPG.

 

Thanks for the input guys... I need more seat time in it on the hiway, last drive got aborted, wrecking yard did not have the part I was after (for the ram). I am slammed at work these days, moved up to 6-7 days a week, 8~12 hr days...

 

there's ones for 60$ that are EXACT copy of the jcw , I used them and other members do too now also, lol I even am using the knock off 550cc ones too and they're working perrrrrrfect. Trust me on these injectors, no pigtail swapping or anything they even run exact tuning as the jcw ones. Can't beat that !

https://www.ebay.com/itm/4PCS-NEW-38....m46890.l49292