ALFAGTV6.COM

[Nikola]

Few months ago I finished restauration on my 82' GTV 6 and I started to drive her and I decided to measure fuel consumption because for some reason I was very much suspicious about her fuel consuption.
So I started measuring fuel consumption and I came to conclusion that she spent 19.5 litres (4.3 British gallons)-(5.1 U.S. gallons) on 100 kilometers (62 miles).I was driving her only in town but I still think that's to much.Why???Because I have also 75 3.0 V6 America also with Bosch L-Jetronic system which has a consumption of 14 litres (3.1 British gallons)-(3.7 U.S. gallons) on 100 kilometers (62 miles) also when driven in town.Now it's winter time in Croatia and I live by seaside and temperatures are from 0 to 20 degrees of celzius which is not to cold and because of that I'm very suspicious about her consumption.
Anybody has some info or idea or previous experience why she is consuming so much fuel???Somebody said that's normal due to old type of Bosh L-Jetronic system but I don't beleive in that story.

[Nikola]

After almost 6 weeks of testing and checking and in the meantime waiting the gas analyzer to come back from servicing we gained something but still I'm not satisfied.With other words I'm very angry and I'm thinking how to set her on fire.Thirsty *****.
Driving it 50 kilometers (31 miles) on open road and 50 kilometers (31 miles) in the city I measured 14,2 liters (3.1 British gallons)-(3.7 U.S. gallons) on 100 kilometers (62 miles).Next 100 kilometers (62 miles) I measured and got 19 litres (4.3 British gallons)-(5.1 U.S. gallons) consumption which I made in the city with mixed driving which would mean fast and normal.
We checked everything and Greg's web page was also helpful.HC,CO,O2 and rest of the parameters were set to normal thru gas analyzer.
One thing I didn't try.The ECU.I have another one and I think I will try with that one so we will see.ECU which is on my car was allready soldered and trouble shooted because didn't wont to start the engine.That was more than 20 years ago.Maybe there is some kind of problem with ECU???

ANYONE,ANY IDEAS,EXPERIENCES

[xrad]

Although all seems normal on your testing(in order of importance):

1) replace the O2 sensor with a new one
2) Yes! replace your ecu with another one.
3) New spark plugs
4) You may have a sticky injector or two
5) Perhaps the resistor board in the Air Flow sensor is shot (test the resistance)
6) new fuel pressure regulator

[MR2 Zig]

Before you do as xrad suggests in his last item check the fuel pressure before replacing the regulator. Also check that the fuel return to the tank from the fuel pressure regulator is clear.

[Nikola]

Although all seems normal on your testing(in order of importance):

1) replace the O2 sensor with a new one
2) Yes! replace your ecu with another one.
3) New spark plugs
4) You may have a sticky injector or two
5) Perhaps the resistor board in the Air Flow sensor is shot (test the resistance)
6) new fuel pressure regulator

1)What is O2 sensor???Is that a lambda probe which is situated in the exhaust just before catalytic converter???If that is the case than I must tell You that my 1982. GTV 6 do not have catalytic converter and O2 sensor.
2)ECU is the number one suspect
3)New spark plugs allready in
4)Injectors cleaned and tested.All O.K.
5)Not shure any more did we test that one but sure it is good idea.
6)Checked pressure and got 2,2 bar which is normal.So if there would be more bar that would mean faulty fuel pressure regulator or clogged fuel return line.

[MR2 Zig]

Good on the testing.

O2 and lambda sensor are the same thing.

We have the O2 sensor and a catalytic converter here, but they are not both needed. The converter can be dispensed with on a good running car with no bad atmospheric problems. The O2 or lambda, however, is how the ECU tells the engine how much fuel to use....if its missing the ECU goes into a full rich mixture mode with the aim of getting you home, its not meant to run that way all the time.

for an example I got 30 miles per gallon (US) on my last trip to San Diego (about 375 miles). My engine is a 3.0 and had just been rebuilt (less than 1000mi on the rebuild at that point). The transaxle has the 3.42 to 1 gears.

I hope that helps,

[Mats]

Check the temperature sensor for the L-Jet. They sometimes go bad and tell the L-Jet that the engine is arctic cold the whole time = a lot of enrichment.

[grant]

While I agree a functioning O2 sensor is critical for the best mileage, other countries received versions of the ECU that don't have an O2 feed back at all.

He would have to source the ECU and likely the wiring harness from another car to have an O2 sensor working.

[MR2 Zig]

Thanks Grant....always good to learn.

I thought all the L-Jet cars had the O2 sensor...I didn't know they had a map reading version.

[Mats]

Thanks Grant....always good to learn.

I thought all the L-Jet cars had the O2 sensor...I didn't know they had a map reading version.

They don't. They just run without feedback.

[Nikola]

First 100 kilometers driving thru town with another ECU I got 14.2 litres on 100 kilometers.That means stop and go,little bit of sideways driving and little bit of normal driving.Tests are continuing and I have a feeling that this time everything would be fine.We will see.

[Nikola]

Second 100 kilometers drive thru town 15.4 litres,also mixed way of driving.Still way bellow 19.5 litres .

[xrad]

save the old ecu for parts....

[Nikola]

This one which is on the car right now is borrowed one and old one I will send to repair if that would be possible.If not I will have a problem.

What would be a normal price for used in good condition ECU???
Anybody have one for sale if I would be buying one???
Of course European one without connections for lambda (O2) sensor.The car is 1982.

[xrad]

There are usually two or three 2.5 ecu's for sale on ebay usa.

If you can't find a non lambda version, consider spending 40$ for lambda sensor from a late 80's Ford mustang and 2$ for a exhaust weld bung.

You would then have to wire into ecu pin connector.