Tuning 2.5td (19j) CAV injector pump

Hi All,

I am trying to increase the fuel going through the engine of my 1987 2.5td as it tops out at 55mph and feels like it is under fuelling even though the turbo is working fine. I had considered the boost diaphram on the side of the injector pump but understand that is only at fault if leaking or the tank pressurising?

I thinik the previous owner must have turned back its fuel to get through an MOT or something. I just can't find much info about tuning the Lucas CAV anywhere - I was told that there is a fuel control nut on the engine side of the pump but I cannnot find anything - any help really appreciated.

Thanks.

There is a max fuel screw, on the pump, but if its comming up againts a artifical limiter then its more likely going to be either the lift pump of your fuel filter.

The max fuel screw does not reduce the fuel being supplied at tick over so this does not affect the smoke produced and hence will not affect the MOT.

When running at peek preformance it will cruse just over 70, but will be screaming away and will take a long time to get there.

I've justed replaced the lift pump and the fuel filter - its not smoking at all, even under heavy load. I thought it should a bit so guess it needs more fuel but I just cannot find the max fuel adjuster! I must be blind but if anyone can explain where it is on the pump that would be great. Thanks.

Check the waste gate actuator as well.

you sure the engine isnt just tired
get the compresion checked out maybe down that will give low power output

My 19J will get to over 70mph - but I get completely paranoid and convince myself it's gonna explode! I stick to 60mph if I'm on the motorway... oh, and there's a 200tdi engine in the garage which is going in the Landy very soon!

instantsquid said:

My 19J will get to over 70mph - but I get completely paranoid and convince myself it's gonna explode!

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I cruise upand down the M1 and M6 at 75mph all the time and although it sounds as if its going to blow up it never has! (that done it for the weekend trip to the Lakes)

Mind you the transfer box has blown up a couple of times - maybe that was because there was no oil in it !

The wastegate actuator on the turbo will move but there is a fair bit of resitance - is this normal?

Also, I still cannot find the fuel control screw on the side of the fuel pump - any suggestions?

I could only dream of hitting 70mph! It tops out at 55mph (does have mud tyres but even so!)

Yes - the only way to make sure it is set correctly is to fit a turbo guage. The most important thing it that the actuator is returning to the closed pos.

The best way to get it going fast is not to push the pedal to he floor, you have to slowly feed in the throtle as it picks up speed as it just over fuels it, which causes incomplete combustion and reduces the efficeny of the tubro, and cuts the power output of the engine preventing it going faster!

But i still think there is some other problem - i'm afraid i don't know where the max fuel screw is as i'v never touched it (at the advice of my local diesel tuning place)

The other think to check is that the pipe from the turbo to the boost diaphram on the top of the injector pump is not leaking as this will reduce boost pressure, and prevent the pump giving more fuel whn the turbo is spinning up

Any ideas where the max fuel control screw is on a 2.5td (19J) Cav injector pump? Thanks.

is it the screw inbetween the pump and engine? ive got the oppisite problem mine flies but lots of black smoke so i need to turn it down and save some fuel

hi i have a defender 2.5td number 4 injector is ****ing out where it sits in the head allready replaced the copper washer that sits in the hole half way down this is a 19j engine

forgot to mention i have just done a cylinder head overhaul all the inlet ports was full with gunk the valves had oil burnt onto them that allmost blocked the ports but the valve stem oil seals was in place but all the exhaust seals was at the top of the valve with no burnt all any way laped the valves in refit the head adjusted the valve clearances what a differance smother no black smoke well happy but this injector has done my head in all day

is the injector seat and mount clean and true ? - is it deffo not coming from the leakoff ?

cleaned it numarus times i did find on the other one that was leaking that if i left out the metal collapsable washer at the bottom they sealed allso replasedthe leak off washers
allso took out the same waser on no4 but still leaking even after hanging on the nuts

martmart said:

Hi All,
I had considered the boost diaphram on the side of the injector pump but understand that is only at fault if leaking or the tank pressurising?

Click to expand...

Not necessarily..
My boost diaphragm was well split but i had NO fuel tank pressurisation so discounted it...
just lack of power & cutting out...
Took me ages to get back to the boost diaphragm.
Its a cheap fix, a couple of quid for a diaphragm & 15 minutes to change it

i was intrested in trying to get bit more out of 19j as well.
mine will sit at 70mph all day (if fact did for 200+ miles both directions in summer) but when running local (all valleys and hills) shes got no guts...any ideas on fuel pump/boost adjusting for bit more torque?

Fitted mine and took her out today, bloody flies, when in my mates 90 we could get just in at 81 but she screamed the thing apart.