Troubleshooting 9mpg Rangie (3.5 EFI)

Hi all,
I am new to the 4x4 world and decided on a RAngie for towing and general 2nd car duties. It is an 86 3.5 EFI (flapper style) which many Km's on the clock but in good running condition.

I was warned by all that it would be thirsty but was shocked at the 30L/100km (~9 mpg) I have found over the last few weeks (not towing yet). I have been attempting to troubleshoot it using help from all sources on the web, and hoped someone on the forum could offer more direction for me. So far I have;

• Checked the plugs (sooty black all round - cleaned and regapped to spec)
• Checked the air filter - dusty but not blocked enough to upset the idle.
• Checked the AFM for all voltages - in correct range
• Checked the Coolant sensor - reading off the scale when cold, but low resistance once warm (and car runs rich enough to stall if connector leads are pulled off it) substituted the sensor with a 180ohm resistor temporarily to see what effect it has if I trick the ECU into thinking its warm.
• Checked the throttel position sensor - rotates smoothly but only hits a max voltage of 3.7V when it has been suggested that it should reach 4.5V?
• Changed the fuel filter
• Checked the fuel regulator for leaks (but havent checked the fuel pressure yet)
• Set timing by ear (still need to check it with gun)
• Checked for hose splits in AFM to airbox & plenum hoses.
• Checked for hoses broken elsewhere.

After all that I suspect I will still get a low economy figure, and low towing power . CAn anyone suggest some other DIY areas to explore or is it time to throw my wallet at a service centre?

Cheers
Ned

Hi

9mpg is not good by any means. My Rangie will do 20 ish on a good day (ok if I do 90 then I will get 9mpg)

This may seem very strange but have you checked the brakes for binding ? or the hand brake for seizure of the prop brakes as this may well cause low fuel economy.

You say you've change the plugs how about leads, cap and rotor arm ?

You need to get the car on a computer to have it checked out as it's not good enough to have the Pot set correctly if everything else is way out

Good indication of incorrect settings see what colour smoke comes out of the exhaust this is a rough guide (Very) Are the cylinder heads gaskets ok ? Rangies can run on for months with a failing one, mine ran for 4 months before finally quitting after doing one gasket (turned out the other side failed)

Black =fuel unburnt
Blue =Oil
White=Water


You could also try a compression test on the Cylinder bored to see if you have a ill engine.

Charlotte

Hi Charlotte,
thanks for the reply. I am glad to see that I do have a fault rather than just have to accept it. I am running out of options, so will probably take it to a garage for an analysis, however most garages i have seen take a less than logical approach also (lets change this and charge you... ok now lets change this and charge you...hmm still not fixed, so lets change this and charge you etc).

Cheers
Ned

Hi

Any Garage which has the "lets change this change that till it's fixed" is not a true engineer.

A True engineer would need to look at it (Most garages are Technicians not Engineers)

Sounds like you need a true engine fitter/engineer

Send me the details by E-mail and I will check the syptoms inc Year of manufacture/any modifications you have done like K&N (puts £5 in the swearbox) LPG etc oh and auto or manual NAS/Saudi/EU Spec. It may help to know exactly what has been done/changed. Send details to the address below and I'll let you know what I think is wrong

[email protected]

charlotte