Fuel consumption high after 2.25D rebuild

Hi guys,

Been fiddling with the series all day about the fuel consumption. Vehicle is a 2.25D 109 s3. Before the engine rebuild, it could go 400+ KM on a full tank of diesel(underseat tank, 45liters). After the engine rebuild, it could only get 300km tops.

For the rebuild, the pistons were put back to original sizing with sleeve liners. The crank and cam shaft had new bearings. Injectors and injector pump were all overhualed by professionals. Timing chain and gears were new. So pretty much nothing has changed expect the reduce in piston sizing.

Engine starts and runs well, but seems to have abit less power than before (just a feeling). Engine was rebuilt because the previous engine had the precombution chamber punch a hole into the block, so i had to get another 2.25D to rebuild , and replace the existing one.

Not much smoke on the exhaust, some black smoke on acceleration. All in all, pretty good for a 2.25D, except that it feels underpowered compared to other 2.25Ds i have driven, and the fuel consumption is high.

I have a feeling the underpoweredness and fuel consumption is closely related. The injector pump might be one tooth out, but i have followed the rover workshop manual word for word, so am not sure if this is the case.

Appreciate any advise! Thanks!

how many miles since the rebuild ?

You might be putting your foot down a bit more due to the power drop.

renorenoreno said:

Hi guys,

Been fiddling with the series all day about the fuel consumption. Vehicle is a 2.25D 109 s3. Before the engine rebuild, it could go 400+ KM on a full tank of diesel(underseat tank, 45liters). After the engine rebuild, it could only get 300km tops.

For the rebuild, the pistons were put back to original sizing with sleeve liners. The crank and cam shaft had new bearings. Injectors and injector pump were all overhualed by professionals. Timing chain and gears were new. So pretty much nothing has changed expect the reduce in piston sizing.

Engine starts and runs well, but seems to have abit less power than before (just a feeling). Engine was rebuilt because the previous engine had the precombution chamber punch a hole into the block, so i had to get another 2.25D to rebuild , and replace the existing one.

Not much smoke on the exhaust, some black smoke on acceleration. All in all, pretty good for a 2.25D, except that it feels underpowered compared to other 2.25Ds i have driven, and the fuel consumption is high.

I have a feeling the underpoweredness and fuel consumption is closely related. The injector pump might be one tooth out, but i have followed the rover workshop manual word for word, so am not sure if this is the case.

Appreciate any advise! Thanks!

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Engine is probably still tight after the rebuild, and should run in in time. What sort of oil are you using?

When you say fuel consumption is high, do you have any actual MPG figures?

Run it on a cheap mineral oil for a thousand KM to help with the bedding in. Avoid synthetics as they will allow the bores to glaze.

divie said:

Run it on a cheap mineral oil for a thousand KM to help with the bedding in. Avoid synthetics as they will allow the bores to glaze.

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Good plan. And in fact, I wouldn't run a 2 1/4 on synth anyway. Not the oil it was designed for, and very expensive!

Millers now do a 20w / 50 semi synthetic oil. Probably a good compromise for anyone wanting to 'upgrade' on the standard mineral oil they use.

Running 20/40 Fully syn hahhaha, still trying to get hold of mineral. So its just the engine bedding in? Should I play with the timing? Thinking of pushing it up/down a gear on the injector pump.

Fuel figures are currently 6.6km per liter, or about 15.6miles per gallon. It used to be close to 9km per liter. Dropped significantly after the rebuild.

30% increase in consumption is a lot even for a new engine being run in, are the injectors good? I would be loath to mess about with the fuel pump until it becomes the last resort.

Col

injectors and injector pump were did together at the same shop. Should be good!

Have you checked the brakes to make sure you don't have a shoe dragging.

Col

Black smoke could be a sign of over fueling - check camshaft timing and then check IP timing

Land Raver said:

Millers now do a 20w / 50 semi synthetic oil. Probably a good compromise for anyone wanting to 'upgrade' on the standard mineral oil they use.

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It is not necessary to "upgrade" oil. Use what the manufacturer specified. In this case, high detergent multigrade mineral oil.

And Miller's is quite expensive. Use Carlube or Comma.

I use Wilko jollop. Cheap as chips and as protective as lard but I change it every three thousand miles or yearly whatever comes round first.

Stretch said:

Black smoke could be a sign of over fueling - check camshaft timing and then check IP timing

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Black smoke could be that it's a Land Rover.

I'm not well up on 2.25D's but are they like a 2.25P with high and low comp cylinder heads maybe your old engine was a high comp one and the new recon'd unit has a low comp head fitted

cornish rattler said:

I'm not well up on 2.25D's but are they like a 2.25P with high and low comp cylinder heads maybe your old engine was a high comp one and the new recon'd unit has a low comp head fitted

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All 10Js are 23:1 or were at some dim point in the past.

blue beasty said:

All 10Js are 23:1 or were at some dim point in the past.

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Are right ok

Try and borrow an injector pressure gauge, they should pop off at 130/135 bar. I have mentioned a few times in the past my "Professional" injector reconditioner got mine from 120 to 165. BIG improvement when set right and so simple to set when you have use of a gauge.

Just leave the filler cap off