Fuel supply pump tutorial

[Spook1205]

Note... sorry for wrong info but this pump is indeed off the 3ltr version. Just found out.

so upon further investigation what I thought was 5th inj line is indeed the return after pressure relief valve.

so the link the White one put up is to be correct on the pump.
so my bad! Sorry guys and gals. But at least it gives you a basic rundown of a common rail diesel pump.

see pic for some basic fuel line info

[Spook1205]

Pictured here is the feed (transfer) pump for the high pressure plunger and low pressure 5th inj.
Cracking 5th inj is a good way to bleed this pump if needed, especially if you get a no start situation after cleaning 5th inj housing.

You can see the intake suction and outlet pressure sides of rotor style gear pump.

[Spook1205]

There is a gauze strainer in the intake of this pump.
Also pictured is the pressure relief valve that bleeds off excess pressure from outlet back to the inlet on the feed pump.

[Spook1205]

Fuel temp sensor is also in the low pressure side of things too. Temperature changes it fuel density so its a very important input to ECU on common rail systems.

Suction control valve shown here is pulse width modulated controlled (they all are) and is by default closed. (some are open by default).
The suction control valve is the go to item for no start, loss of power and rattly engine (all of these are low fuel rail pressure). why? its the simplest, cheapest, easiest most common component that gives these symptoms.

[Spook1205]

The high pressure plunger works off a eccentric crank with a square block that will walk back and forth between two plungers.
Fuel pressure is regulated by how much fuel the suction control valve allows to fill the plunger chamber. less fuel means less pressure and plunger doesn't extend for full stroke.
Plunger and chamber are machined to very fine tolerances.

[Spook1205]

More related pics to pump position and components.

[Spook1205]

A couple of views of components laid out.

Cheers, Spook

[JohnLynn]

Another interesting and informative post Luke, it is surprising how complicated something seemingly simple like a fuel pump is on a modern engine. The main pump looks like a conventional hydraulic pump but the eccentric cam looks huge. The gauze filter must be thought necessary to avoid damage to such a close tolerance device but you would hope it would not be needed after the main filters in the system.
I hope that you were allowed back in the house after all this, I am usually banned if I have been bleeding fuel on a tractor or marine engine as I stink of diesel.

[Spook1205]

Thanks John,
Most earlier model pumps I have pulled apart did not have a gauze filter this size. It’s pretty course too.
Getting back in the house is always a contentious problem especially after a front steering knuckle rebuild 🤷*♂️

[White One]

Well done Luke , did the engine start after you did this job lol? How much work is involved to R&R the pump? any special tools required ?

a few more diagrams here - https://toyota-club.net/files/faq/15...engine_eng.htm

[Spook1205]

They are pretty much a replacement item as a whole.
The pump on that diagram isn’t on our engine. I learnt this when I pulled this one down.
Easy to strip down though

[Spook1205]

Sorry guys found out pump was off the 1KD
My bad!

[White One]

I know the 1KDs can be a nightmare , if the fuel pump corrodes or loses any metal particles they end up getting flushed into the commonrail , injectors , fuel lines , tanks , etc. a big job to remove and clean all these parts.
The 1 GD has a 2 micron filter on the block to avoid particles going into the injectors.

[Spook1205]

Have you found anything on service life of the 2 micron filter?
I am guessing it’s only on a needs basis. It’s a pretty big housing.
Still a concern of long term is fuel pressure wearing inside of high pressure pipes on the bends. Baileys have noted wear and recommend replacement after a certain km range.
I am seriously considering at 200000kms to do timing chains, injectors and pipes when I re- clean intake.
It will be costly to buy components but long term trouble free motoring from preventative maintenance is important to me.

[White One]

ive not seen any discussion on replacing the block filter at regular intervals . Although not serviceable as such i guess you can remove the end cap ( 4 hex screws ) and take a look inside. A hilux mech has replaced them whenever someone has filled the tank with unleaded. starter motor has to be removed for access.
On the 1KD they reccommend doing injector pipes at injector time. Maybe the pipes on the 1GD are better in this regard ?

[Spook1205]

That makes sense to replace it if filled with wrong fuel.
Maybe I’ll add it to the list for 200000km.
Hopefully pipes are better but will rely on baileys diesels opinion for that. If needed will buy injector pipes off them and get them to do injectors. Their process of rebuilding injectors is very professional.