running rich

[big rich]

hi all my 1.8t is running rich and useing a lot of fuel any one got any idear,s on how to fix

[pernix]

Failed lambda sensor............
Faulty coolant temp sensor.......there are two it would be the one that controls the ecu

[T-Cut]

Do you know the running temperature? I mean the accurate temperature using the trip screen diagnostic mode. See section 7.

Diagnostic Mode: http://www.the75andztclub.co.uk/forum/showthread.php?t=55585

If it runs much below 90C it will affect mpg.

TC

[Arctic]

Do you know the running temperature? I mean the accurate temperature using the trip screen diagnostic mode. See section 7.

Diagnostic Mode: http://www.the75andztclub.co.uk/forum/showthread.php?t=55585

If it runs much below 90C it will affect mpg.

TC

Hi Adrian/Cyrano.
I was at Richards last Friday and the temp is ok gets up to 104 and the fan kicks in as it should but it was only ticking over on the drive do not know the temp when driving would it change :shrug: not really up on the 1.8 so would like to know my self why they run rich or not get good MPG if all else is ok no sign of HGF

[chrissyboy]

could be air flow meter or engine air temperature sensor

[big rich]

where would i find the engine air temp sensor

[T-Cut]

- - - do not know the temp when driving would it change - - -

The typical running (driving) temperature is 95-100C. If it has a PRT, this will cause increased cooling as the revs increase. It's a balance between heat generated (fuel rate) versus engine revs (coolant pump pressure) and works very well IMO. The PRT action is easily seen by driving at constant speed in a high gear below 2000rpm. Let the temperature stabilise. Watch the screen and change down a gear but keep road speed constant. As the engine goes above 2000rpm, the PRT's pressure valve opens and the temperature falls a couple of degrees.

TC

[Steve1966]

My 1.8 Man (non turbo) has only managed an average of 32.5 mpg over the last 10,000 miles of mixed but gentle driving. I would have thought it should do better than this. If any of the items mentioned previously have failed (Lambda sensor etc) would they put the engine light on? I have no other issues. Engine temp is fine with a new stat last year and running at 90/91.

[big rich]

hi T-cut whats a PRT if its the thirmerstat it has the old type on the back of the head

[greendriver]

The typical running (driving) temperature is 95-100C. If it has a PRT, this will cause increased cooling as the revs increase. It's a balance between heat generated (fuel rate) versus engine revs (coolant pump pressure) and works very well IMO. The PRT action is easily seen by driving at constant speed in a high gear below 2000rpm. Let the temperature stabilise. Watch the screen and change down a gear but keep road speed constant. As the engine goes above 2000rpm, the PRT's pressure valve opens and the temperature falls a couple of degrees.

TC

I "use" my PRT all the time because the slow speed has gone on my fan, so I have to keep the revs up to reduce the temp if it goes too close to 100...this would explain why I am getting about 26MPG at the mo...saving for a kenlowe conversion.

Sorry for going slightly off topic.

[Mischief]

Mine has been running rich since i had the inlet manifold changed, you can smell the petrol on startup every time :shrug:

[big rich]

can sombody please tell me what this PRT thing is as i dont know what it stands for

[greendriver]

i believe it means pressure relief thermostat. It is underneath the engine, near the turbo (if you have one). Some garages see a "missing" tstat at the back of the block and think they should install a stat there. This is incorrect as I understand it.

[big rich]

no mine has just got a normal stat on the back of the engine