I am only getting about 18- 25mpg tops on my car. What could be wrong. I know its a how long is a piece of string but:
The performance is good still but, when i back off the throttle after accelerating i get a rally style popping in the exhaust, sounds good but whats causing it.
Also I have an LCD dash in my car. I have a 1.8 8v engine and f16 gearbox in it. The petrol indicator never gets above half when the tank is full. I have been told this is because i have a smaller fuel tank, ok fair enough, so fitting a GTE 16v fuel tank should fix this then. But i have also noticed that it only goes down by 2 bars not 1, is this normal. Why have 4 bars per section on the dash if you only go down by 2. Opinions please.
The LCD problem with the fuel guage only sitting at half way is because the 1.8's only have a 9 gallon fuel tank, whereas the GTE 2L have an 11 gallon.
The Digital Dash is also switched to the 2.0 mode, I done this as with the 17's on it made the speedo only 3mph out.
If your wanting it to work to the max then by all means change the tank, but bigger tank = more weight = slower car!! >)
As for the bad fuel consumption. Well you've gotta expect it with a modified car, I had it all set up on the rollers where he adjusted the boost valve and all that, it ran a lot sweeter afterwards.
I use to get 225 miles out of a tank, which ain't too bad considering the size of the tank and the modded engine. Maybe it might pay you to get it on the rollers again??
As for the popping noise, great ain't it!! Probably being caused by the increase pressure in the fueling system, standard it should run 2.5bar, standard FSE boost valve comes at 3 bar, I believe that valve was running closer to 3.5/4 bar!
It's a catch 22 situation do you want econamy or do you want performance??
Dave, the only reason i posted was the fact that i have seen better fuel economy from the car thats all. About 6 weeks ago i was getting 30-35 mpg now its 18-25. I know that its a modified engine and if the fuel economy was consistant i would not be bothered, but its the fact that it was brill now its not. I mostly drive quite sensible, but on occasion boot it a lot. When i do boot it a lot i notice even worse fuel econ which is fine and too be expected, i just wonder what has brought the mpg down.
As for the LCD, best stay with a smaller tank then, big tank,slower, yuck.
Lastly the popping is cool, but was not sure if it was because of something bad, but if its the exhaust/higher fuel pressure then great.
all bar the fuel guage thing i have exactly the same prob at the moment. The temp guage sits at blue bar lit, and one yellow bar lit, which is lower than the usual 1 blue two yellow. I'm getting haenous amounts of kangarooing, and mpg is completely ludicrous around town.
Without getting into too much detail i suspect its the ecu temp sensor in both our cases. its thinking the coolant is cold, indirectly the engine must be cold so its running rich all the time as if youve just started your car up in the morning. For you i reckon try and source another sensor, or clean up yours and make sure theres good connection to the multiplug. Ive got lots of other issues like my radiator leaking and coolant system not pressurising.
Overfuelling sounds likely. Have you checked the ECU temperature sensor. Cos if that isn't working then the engine will run on the warm up mode all the time. Which means loads of extra fuel. Which means poor mpg and popping noises on the overrun.
Get an error code reader plugged in.
As to fuel tank, it'd be worth checking all of the wires and also maybe the float is knackered. I've had them leak before so that they don't go full up.
Don't bother changing the tank though.
You can check the display by disconnecting the fuel level wire. The display should either go full or empty then.
Then earth the wire and see if the display goes fully the other way.
It's located around the back of the block on the 8v, behind the alternator. About £12 or so to replace. You can test it by using a multimeter to check the resistance at different temperatures. Use this guide here -->ECU Temp Sensor
I had a similar problem with mine, when my sensor went tits-up. Very difficult to start hot or cold, and BAD fuel consumption
Ok, I've been having similar problems for a while with Fuel Consumption and the cars definately running lean. (c20xe) In the past 2 days my temp gauge has started showing half way between the blue and first mark. My SRI did this and i changed the thermostat to fix it. Could it be the sensor on my GSI??? Where is it on the GSI????
Thanks for all the sound advice guys. This is great. Will keep my hands dirty for a while. Glad to hear i am not the only one with this type of prob.
isnt it funny when everything runs sweet as a nut, and you think finally i have ironed out everything. then all of a sudden loads of stuff happens.
Car was perfect for a while. i thought great perfect car but then:
Fuel Economy goes to crap,
Rear wiper motor blows,
12 Disc changer brakes.
All but the fuel economy thing fixed now though. Fingers crossed nothing else for a while when its all done. That will teach me to think everything is perfect. Wont do that again.