Thread: Quote to tweak 300tdi fuel pump...can someone explain this to me please

Originally Posted by Roverlord off road spares

Angus,they are talking the injector pump. But consider in all reality, its a Bloody 300TDI and it will never be a Ferrari!

Done some mods to the 200tdi, pump, intercooler upgrade replaced front box with straight through pipe, it's not about the ultimate power, but getting rid of turbo lag and more grunt, makes it much better to drive. Gear lever mod lt77 gearbox mod at DuckDuckGo is good as well.

There are lots of postings on how to adjust fuel pump yourself (5 minutes work if you keep to the simple mod).

I added a digital EGT gauge (A$70), turbo EGV bypass adjuster valve (A$20 to adjust when the bypass valve comes in) and a sports intercooler (A$1k). I removed the resonator on the end of the exhaust and added a stainless steel extension piece (A$50).

Without the dyno its a bit hit and miss, but it improved my output without making too much difference to noise level. A larger bore or straight through exhaust can help but can attract the authorities. A bit more smoke however due to a richer mix.

Mines an auto, so I fiddled with the kickup/down adjustment to adjust at what revs it changes gears. Again, hit and miss and lots of postings on how to adjust this.

This all gave me a slight improvement without risking damage providing I don't exceed 2 Bar on the turbo.

I have a 300tdi auto defender had the tweaks done at turbo engineering in Thomastown 150000 kms ago very happy, it used to struggle to hold 100kmh no problem now love it

Geez $2000 - seriously?
A mechanic from British Off Road spent five minutes with a screwdriver fiddling with our previous D1 300Tdi in the car park, explained that it was important not to overdo it or there would be problems, and didn't even charge us, as we had just spent a fair sum on other work with them. Off we went and a little puff on startup was all we had, and it was still running great when we sold it.

i) good intercooler- allisport, APT etc,


ii) tune up the fuel pump as described in the pdf, see attached ; Full credit to Ian Peterson, and watch your EGTs careful not to over fuel.

I did it progressively, make an adjustment drive for a couple of weeks , then come back and make another adjustment, record your adjustments.

iii) you can increase your boost up to 18-20 psi, measured at the manifold, not at the turbo outlet.

this will give the best improvements for not much money IMV.

if you want to progress further you probably need to fit a better turbo, garrett VNT etc.

I removed my center muffler, but didn't notice anything performance or noise wise.

I'm running; adjusted fuel pump, APT intercooler, silicon hoses, garrett 2256 VNT, set to 20 psi max boost, no center muffler.

the car is much more driveable, cruising economy is improved, EGTs are lower.

The Tdi is a great little engine, and can give reasonable performance, (just), if tuned up. I found it a bit of a pain to drive before I did some tuning.

good luck,

cheers simmo

Angus, for what it matters, I’ve done a lot of testing on my 300tdi over the last 4 or 5 years to understand how to get a little more out of the dated tech . This includes “on road logging” of not only EGTs’ but also induction temperatures and pressures at the intake, compressor outlet, intercooler outlet and plenum chamber, fuelling changes etc.
The gear I use is a little more accurate (NATA certified) than most would get their hands on. The logs are still around here somewhere if needed, however the issue most will overlook is what you gain by only increasing fuel rates or pressures.
To get the full value of more fuel you need more air.The major concern is heat management (typically more fuel = more egt) and many below have rightly recommended a good EGT which you already have. The heat coming into your engine from your induction is your next concern. If you still have the OME Garret GT25 hanging off your engine don’t be surprised to find the air coming off the compressor wheel in in the vicinity of 120 – 140`C at 16 psi boost (with the ambient around 25`C and engine rev’s of 2000 – 2500). I tossed the OME intercooler years before, so I don’t know how it will perform, however the PWR intercooler only dropped the induction charge to around 60 - 80`C at 100kms road speed (same ambient temp). EGT on level ground was around the 550 – 650`C (depending of fuel pump setting & right foot orientation)

Adding only extra fuel typically increases the difficulty of heat management (not just EGT)
Because the induction charge is hot the air is also expanded and you lose a little of your charge as well. Increasing the boost on the OME garret only pushes the temps up further.
Go back to basics. “If it don’t flow, It won’t go”.
For what it’s worth I subjected the OME turbo to a floatation test which it failed and fitted a variable geometry Garret (the same one that was fitted to the 2.8L Spanish 300tdi). It’s bolted up to a 2.75” mandrel bent exhaust that I had manufactured about 10yrs ago. As mentioned above my intercooler is a PWR that is also about 10yrs old.
Air coming off the compressor wheel is now (or when I last checked) was about 50 – 60`C at 16psi boost (with the ambient around 25`C) and out of the intercooler around 27-32`C out of the intercooler. With the inlet temp you get more air charge in the cylinders and a slightly lower exhaust temp which will let you add more fuel and get more go.
I now develop boost threshold by 1100rpm, easily have 6psi boost by 1200 and 18psi before 1400 rpm. Highway fuel consumption is about 9L/100kms.
My fuel pump is still original although I have a rebuilt (and slightly tweeked) Bosh VE sitting on the bench if I ever get game. When your wife can step a D1 sideways in a corner changing up in 2^nd and flooring the loud pedal you think twice about how much torque the R380 gearbox will stand.

Parts for the Bosh VE are about $200 from memory, but I leave that part of the game to my brother as fuel pumps are his trade, so I can’t comment on labour, except it took him less than a day to work his magic.
I’ve also worked some other magic like ceramic coating on the head, runners, valves etc. that have other effects and I won’t go into here as this is already way too long. You also need to consider where you sense the boost pressure for the turbo and whether you measure EGT before or after the turbo (there is a difference). Also worth measuring the engine block temperature.
The fuel pump tuning guide by Ian Peterson is a great guide. I think from memory he recommends marking your start point on diaphrams, screw etc and you should take his advise.

Originally Posted by GeoffT

Angus, for what it matters, I’ve done a lot of testing on my 300tdi over the last 4 or 5 years to understand how to get a little more out of the dated tech . This includes “on road logging” of not only EGTs’ but also induction temperatures and pressures at the intake, compressor outlet, intercooler outlet and plenum chamber, fuelling changes etc.
The gear I use is a little more accurate (NATA certified) than most would get their hands on. The logs are still around here somewhere if needed, however the issue most will overlook is what you gain by only increasing fuel rates or pressures.
To get the full value of more fuel you need more air.The major concern is heat management (typically more fuel = more egt) and many below have rightly recommended a good EGT which you already have. The heat coming into your engine from your induction is your next concern. If you still have the OME Garret GT25 hanging off your engine don’t be surprised to find the air coming off the compressor wheel in in the vicinity of 120 – 140`C at 16 psi boost (with the ambient around 25`C and engine rev’s of 2000 – 2500). I tossed the OME intercooler years before, so I don’t know how it will perform, however the PWR intercooler only dropped the induction charge to around 60 - 80`C at 100kms road speed (same ambient temp). EGT on level ground was around the 550 – 650`C (depending of fuel pump setting & right foot orientation)

Adding only extra fuel typically increases the difficulty of heat management (not just EGT)
Because the induction charge is hot the air is also expanded and you lose a little of your charge as well. Increasing the boost on the OME garret only pushes the temps up further.
Go back to basics. “If it don’t flow, It won’t go”.
For what it’s worth I subjected the OME turbo to a floatation test which it failed and fitted a variable geometry Garret (the same one that was fitted to the 2.8L Spanish 300tdi). It’s bolted up to a 2.75” mandrel bent exhaust that I had manufactured about 10yrs ago. As mentioned above my intercooler is a PWR that is also about 10yrs old.
Air coming off the compressor wheel is now (or when I last checked) was about 50 – 60`C at 16psi boost (with the ambient around 25`C) and out of the intercooler around 27-32`C out of the intercooler. With the inlet temp you get more air charge in the cylinders and a slightly lower exhaust temp which will let you add more fuel and get more go.
I now develop boost threshold by 1100rpm, easily have 6psi boost by 1200 and 18psi before 1400 rpm. Highway fuel consumption is about 9L/100kms.
My fuel pump is still original although I have a rebuilt (and slightly tweeked) Bosh VE sitting on the bench if I ever get game. When your wife can step a D1 sideways in a corner changing up in 2^nd and flooring the loud pedal you think twice about how much torque the R380 gearbox will stand.

Parts for the Bosh VE are about $200 from memory, but I leave that part of the game to my brother as fuel pumps are his trade, so I can’t comment on labour, except it took him less than a day to work his magic.
I’ve also worked some other magic like ceramic coating on the head, runners, valves etc. that have other effects and I won’t go into here as this is already way too long. You also need to consider where you sense the boost pressure for the turbo and whether you measure EGT before or after the turbo (there is a difference). Also worth measuring the engine block temperature.
The fuel pump tuning guide by Ian Peterson is a great guide. I think from memory he recommends marking your start point on diaphrams, screw etc and you should take his advise.

Some good info there Geoff, seems the larger compressor wheel on the VNT gave you the air flow you needed without superheating the air then?

You can help keep the EGTs in check with a little timing advance, it also helps to keep smoke levels in check. The issue with advancing the static timing is you lose low range torque which is where a Dynamic Timing Advance Spacer kit comes in allowing you the best of both worlds.

You did well to get your charge air that cool tbh!

Here is evidence of the dyno figures for my 1998 (12 month build) 300Tdi 130 HCPU. (Car sits on 285/75 R16 Mickey Thompson MTZ's, weighed 3T at the time of the dyno)

I have posted this previously so do a search on the forum.

It was only $300 from memory for the actual dyno tune and the results were amazing. Such a different car to drive.

But there was also the cost of the Allisport intercooler, EGT and Boost gauges (plus a dash top MUD pod to house the extra gauges) which I all installed myself. The exhaust is a 2 & 1/2" pipe straight through with no mufflers. The Boost gauge feeds from a blank at the back of the manifold (you'll need to buy a threaded barb M12 x 1.5). The EGT feeds from the blanking plate before the turbo.

I have owned my 130 for nearly 9 years, but the last two and a half years after the dyno tune ( and I'm just about to hit the illustrious 300,000km mark) I still get a smile on my face when I plant my foot on the accelerator. But hey its no Ferrari!