[RaceCraft]

Ok symptoms are:-
Car: AU2
When the fuels get down to 1/2 or less the car starts to run very very rough.. It won't idle almost to the point where it seems to be running on 2 cylinders... Now the car is undriveable, and the only solution is to leave the car sit in the shade for a few hours or re-fill the tank all the way back to full... I have already replacd the fuel filter, ISC and had the injectors cleaned, also tried running it with the A/C on and off..

The wierdest part is that without fail as you get to 1/2 tank of gas the engine starts missing.. From my understanding fuel injected cars shouldn't suffer from vapour lock but this sure sounds like vapour lock is the root of my problem..The car runs fine all night and really seems only to suffer during the day

I'm at the stage of replacing the fuel pump but other than that I have no idea what else to try...Any ideas, tips or similar problems would be great

Cheers
Tibbo

PS: always keeping the car full is not an option
:fraz: :fraz:

 

[Dellboy999]

Try driving with the fuel cap a little loose when you get near half, maybe the tank gets some weird vacuum pressure thing going ???

 

[RaceCraft]

Ok.. stage 2 is comlpete .. i have just replaced the fuel pump and filled the car all the way back to the top.. Now another strange thing has reared its ugly head... The ECU is now telling the odometer display that the DTE is only 203 klms.. I'm starting to think there is a problem between the ECU and the fuel sender.. I'll see if i can word this correctly: The car shows a full tank but the DTE is only 200klm.. Now when i do 200 klm and physically still have 1/2 a tank of gas the DTE would be showing 0 klm.. What sensors and adjustments does the DTE use/make and where does it get its data from? For example when the DTE is at 0 would it not somehow shut the fuel pump down to stop it from burning out?

 

[Dellboy999]

Well my car is an EA Gia, but I do get a similar problem at times, mainly if am empty and I put in half is still thinks I have 80k's left and gets upset, it just says about 80k's sometimes re-adjusts its estimate, but mostly says 80k's till eventually it is really 80k's, but I fill it up it re-adjusts to normal just fine.

Jason

 

[EBXR]

Is there any crap in the tank??

I a similar experience with a previous car, and it turned out to be masking tape floating around in the fuel tank. It would only do it when the tank got half way...

 

[Rollin]

the DTE should take in to account the fuel level in the tank and the present rate of fuel consumption (in L per kilometer) - if you thrash it mercilessly the DTE should take a big dive, and if you drive on the highway at light throttle it should improve.

the fuel pump will not shut down when the DTE gets to empty - the car will run as long as fuel is getting to the injectors.

as for whats causing the problem i cant think of any reason......apart from what EBXR said above of course.

maybe put a fuel pressure gauge on the car when it is playing silly buggers and see what it reads...

 

[XWish Ute]

Is the gauge actually reading correctly? Not sure how difficult it would be on the AU, but note where the gauge is, then fill the tank to full. The amount should tell you if the gauge/sender is OK.

 

[TIKFD6]

Have you checked that none of the breather lines on the fuel neck are kinked?
I had this happen once, and it nearly blew me away with pressure when i opened the tank.