help!

[jeff211]

does anyone know if a aaz93'-97' (230223506274)M-tdi pump will work on my 98' VW TDI block?

[Justin]

it will definately run, you might have to adjust the fuel screw a little. what is the breaking pressure of the two sets of injectors that you have? if I remember right the TDI injectors that I have are 190 bar, I am not sure what the 1.9 IDI are. my M-TDI pump has a 1.9 IDI cam plate in it along with other modifications.

the main difference will be injector lines will most likely be different but the pump will power the TDI

calm down you will have a running M-TDI (and never go back) soon enough.

later
justin

[boxer246]

Justin,
So are you saying that with a simple fuel screw adjustment, a 1.9AAZ IDI pump will power a TDI appropriately?  You say your M-TDI pump has a 1.9 IDI camplate "along with other mods" and it works well, apparently, but have you run a TDI with an AAZ pump by simply tweaking the fuel screw and nothing else?  I'm not questioning your validity, but I want to be sure I understand the advice you are giving.  

My reason for asking is this;  I am building a TDI for a Vanagon and hopefully will build an M pump.....so I have been doing some research, but still lots more to do.

Everything I have read so far from folks that have tried to run a stock, or nearly stock IDI TD pump on a TDI all say the same thing....that it runs terrible, several have even equated the power output to a 1.6 NA motor, or maybe a badly running 1.6TD.  Several people on this forum that seem to be very knowledgable about building M-TDI pumps (TinTin, Hillfolk'r and RabbitGTDguy) have echoed each other on several occasions about the importance of building a pump with not only the proper components using possibly several pumps, but also taking into consideration other timing, advance and fueling issues, some of which I have a decent grasp on, some I dont.  

So.....sort of round circle, sorry for being long winded, but how exactly well, from your personal experience will a TDI run with a stock TD pump?  
I would also be interested in what "other modifications" you have done to yours.

[boxer246]

Justin I just read your signature and it shows you have a Giles pump on your truck.....so he probably doesnt want his secrets out.....that's OK!  But whatever tidbits you can give, would be appreciated.

[hillfolk'r]

i took my pump(12mm modded) right off my old 1.6 and put it right on my tdi....runs great..whats the problem??

[boxer246]

Hillfolk'r......I didnt realize that.  I stand corrected.  Thats cool....somehow I thought you were running a pump with lots of goodies and trickery inside.  Well maybe a few others can chime in on this one and see what we find out.  Ten brains are better than one.  Thats why I love these forums, what the he-- did we do before the internet?  Oh yeah, picked up the phone  :shock:

[Justin]

Yes I have a Giles pump and I love it, the only thing that I know of about the pump is this
its originally a 1.6 or 1.5 L IDI pump (I sent it in to him) with a 1.9 L IDI boost aneroid (again I sent it in) When I sent the pump in it had a TDI camplate and 11 mm plunger head that I installed, got the wrong spacing and messed up a bunch of internals because the pump essentially went into valve float with the increased spacing (I will leave these assembies to the experts from now on since I dont have the proper tools to check those spaces, unless someone is willing to enlighten me.

so the Plunger head on mine is a 10 or 11 mm (cannot remember, I think its a 10mm), 1.9 IDI cam plate I have heard that the 1.9 IDI cam plate is easier to build a performace pump with because its not as agressive a profile as the TDI's. Beyond that I dont know the specifics of what Giles does internally. I do feel bad that I dont have the engine built to the point of taking full advantage of Giles's pump since he told me that my pump has enough fuel capability to handle 40+ psi of boost, but I know that someday I will be able to build a stout 1.9 TDI with a big twin turbo setup and my giles pump will hang with it all day long.

sorry that I cannot be of more help, I think the issue of a lot of the IDI pumps not running TDI well is that the fuel has to be turned up so much to get the injector line pressures up, thats where the 1.9 IDI camplate and larger plunger heads get the job done without having to tweak the fuel way up, you either have a larger plunger head for more volume/pressure when compressed or a longer stroke cam plate, the rest other guys can help you with that a lot better than I

later
Justin

[Tintin]

A TD pump with 12mm head equal approximately at a TDI pum with 9mm plunger,  give around the same power level, definately better than a stock TD pump.

Stock AAZ pump on a tdi work well with 216nozzle,  but the power is bad and the idle is rough below 1200rpm, and that smell very bad at the tail pipe.

10mm in AAZ pump, the idle come fine.

11mm in AAZ a little better.

12mm  etc......

To equal a real 10mm TDI pump that take a 14mm plunger in IDI pump.

I have tested all this.

[jimfoo]

A TD pump with 12mm head equal approximately at a TDI pum with 9mm plunger,  give around the same power level, definately better than a stock TD pump.

Stock AAZ pump on a tdi work well with 216nozzle,  but the power is bad and the idle is rough below 1200rpm, and that smell very bad at the tail pipe.

10mm in AAZ pump, the idle come fine.

11mm in AAZ a little better.

12mm  etc......

To equal a real 10mm TDI pump that take a 14mm plunger in IDI pump.

I have tested all this.

Does the lift of the cam plate of the IDI matter much in that respect. I'm referring more to the high lift version of the AAZ pump. I would think it should make a little difference as a higher lift would push more fuel. This is more for everyone else's info than mine. Then again maybe the high lift cam plates all had the smaller plunger foot so wouldn't work with a larger head, I don't know.

[Tintin]

euuhhh...  the lift have no effect on the fuel quantity,  never a pump inject the fuel in the total lift of the cam plate, only a variable part of the lift is using to inject the fuel, idle to full throttle, It's not a pump to fill a 5 Gal tank, the diesel engine need a variable amount of fuel (IQ).

The thing is the profile of the cam in relation with the engine degre rotation, it have a windows in the piston stroke that you can inject the fuel,  before or past this windows,  it's bad.

Also TDI engine have a smaller windows than IDI,  thus a TDI need more aggressive cam, the plunger move faster and able to inject a large/proper (IQ) volume in a short time,  or less aggressive cam with bigger plunger can inject a large/proper (IQ) volume in a short time.

Short time: + or -  proper amount of fuel inside the windows, idle to full throttle.

Injection pressure and RPM is another story wich complicated the axplanation.