!991 740 estate 200f

Hi guys,

Just purchased a 1991 740 estate with the 200f engine and auto gearbox, it was running extremely poor , but after a bit of elbow grease got it running perfect and idling at 750 rpm. changed filters ,plugs, leads, belts and done the cleaning of icv and throttle body. My problem is that i am only getting 75 miles out of £20.00 of fuel. The next step would be to have the injectors cleaned and re-nozzled, but would like some expert advice first, the car has done 191000 and two owners from new, the car is near enough showroom condition, but the fuel consumption is bankrupting me.
Your advice much needed.

Many Thanks

Tidge.

[classicswede]

Well gas it then that will save you a fortune.

Just another thought, would a faulty air mass meter cause the high fuel consumption? Not getting any fault codes 1-1-1, car idling at 750-800 rpm with no problems, just the fuel consumption at about 15 mpg.
Cant think of any thing else it could be.

[ivor940]

Hi, The usual codes for hi fuel usage are 1.1.3, 1.2.1, 2.1.2, 2.3.1. You say there are no codes apart from 1.1.1 showing. Try taking a plug out. Is it blackish? Is the core biscuit color? As your engine is B200f, check the warm air flap system. If it is not working, could cause snag. Also check car is warming up correctly. Is fan stuck so it is overcooling rad. Is all your driving around town on short journeys. Do you have a locking fuel cap ( is someone taking fuel) Have you checked Ful to Full gas milage?

ivor940
94 940 2.0 SE Turbo est 5 spd 164k
VOC member

Hi Ivor940,

Petrol cap is locked,that was my first thought. Have not checked the warm air flap as yet. When i first got the car i checked the fault codes, there was one logged 2-3-2, which i think is lambda sensor or leaking injector. I have cleared the faults and run the car for a week, but the fault has not recurred.I am in the midst of a full tank to mpg trial at the moment and will reprt back with the results when i have them.It is true i do a lot of stop start town driving, but the mpg still seems a bit excessive. The exhaust does seem to have a ecessive petrol smell, but that could be just me having had diesels prior to this. Thinking of replacing the lambda sensor at the weekend anyway, but the car has just passed MOT with a co2 reading of .52%, so not anticipating any change in the mpg with the replacement lambda sensor.
I will also check the warm air flap to.
If you any more suggestions please throw them this way.

Many Thanks

Tidge65

[Citizen.Agfa]

Wotcher. I know this aint a direct comparison but: I owned, for five years, a 1987 740 GLE 2.3 Auto (4 speed) estate which regularly returned "run" average mpg's of 34 but resolutely refused to do anything better than 17 mpg round the gigantic conurbation that is Lampeter (pop. 2-2.5k). Sometimes it would drop to 14; this was a reasonably well looked-after car, oil and filters @ 6k, new leads every couple of years, regular plug changes etc, but it had to go cos I can't afford fuel consumption that wouldn't disgrace a three and a half litre V8!
Regards, Nick H.

Just a quick update, Done a voltage check on the lambda sensor, its giving a constant .02v even when the car is revved, then checked the obd and getting a 2-3-2 code, so i am assuming the lambda sensor needs replacing.

Well, I can sympathise with Tidge, I'm getting v poor mpg, having changed plugs and filters, the diagnostic code was for the Lamdba sensor (note is cheaper to get from online than GSF or the Volvo club parts supplier !)
Now the diagnostic code has indicated the air mass meter.
GSF quote £219 (£40 back when unit exchanged), or Carpenters £260 inc fitting !!
Online it's only $210 from Drivewire.com !!
Hmmm, something amiss I think.

It's a great car, old but goes, has done 96,000 , but is sadly an auto !!
I want to keep it, but may be forced to sell to get something more economical.

[James A]

I only get about 100 miles from £20.00 worth of fuel with my 740SE, despite it being correctly tuned and regularly serviced. I'm sure that drivng the thing like it's a XR3i doesn't help matters greatly

Better to have a thristy, but safe car than an economical one with poor primary and secondary safety, I say

Just an update, done 160 miles on 60 litres of fuel, decided to change all four injectors, car seems to be running a lot smoother. Will do another fuel to mileage comparison and then give another update.