1.8 16v timing question

[stemid 0]

Just wondering what is the best timing position for my valver. My average mpg is cack, getting about 250 miles to a full tank of petrol, and that's driving sensibly.

 

Anyway I read on here that 9 degrees BTDC is ideal for these engines. rather than 6 degrees where it should be set to at the moment. Would or could advancing the timing sort my mpg out, or will it give higher performance and thus lowering it?

 

To be honest I'm not overly bothered about it having loads of power right now, need to save some pennies on fuel.

 

Checked the plugs, but they look reasonable. Could changing the ht leads help? Convinced it's over fueling somehow. No lambda probe, being a 91 model. Can't find and vacuum leaks either.

 

Gonna check if the rear brakes are binding but pretty sure they are not.

 

Advise would be much appreciated.

[flusted 0]

advancing the timing will increase power but 9 degrees is normally on a valver with flowed head or different cams etc

Its a case of trying it and see if it pings

 

If you can get the co set to 2% with about 8 degrees advance it should fly

[stemid 0]

ok so timing is not the problem here then. racking my brain for what else it could be.

 

are the injectors a possibility?

 

forgot to mention that I have trouble starting it from cold. replaced the ignition barrell and ignition switch

[bcstudent 0]

If it's a 1.8 with the 12 gallon tank, then 250 miles isn't far off. You'll probably only see 300 tops if you stay out of the town.

[davidwort 0]

Few things to check:

If it's over fuelling the plugs will have black sooty deposits on them.

Check the air filter is clean, the plugs, leads dizzy cap etc are in good nick.

Is the exhaust in good condition?

Bad spray patterns on injectors won't help fuel consumption.

has the Warm up regulator been fiddled with? - tamper proof brass cap underneath it when the unit is un-bolted from the head.

Are your tyres inflated correctly, is the alignment right?

Have the CO checked, should be between 0.5 and 1.5, a strong engine will run better at the top end with it at 2% as mentioned.

Have you had a compression check done?

The favourite for sluggish performance and low fuel economy is a timing belt one tooth out, compare the pulley timing marks to the flywheel mark.

I've hardly ever got less than 30mpg on my K-jet valver and my current 2L block running the 1.8 injection will always make 350 to the tank on tesco 99. A good condition 1.8 with mixed driving should be making over 300 miles to the tank unless you drive in town all the time.