Engine Specific Info and Questions > Diesel Swaps

mTDI caddy up and running but not building boost or power

(1/11) > >>

thegimpster:
I bought this caddy with a AHU in it off a friend. When I got it it was running but using a 1.6 N/A pump on it and the cam was 180 out. The turbo wasn't hooked up, just sitting back there sucking debris. Don't ask me how it was running, but it was. I pulled the pump off of it and put a mTDI pump on it I got with another car. The info that I got on the pump was that it was an AAZ pump with TDI internals. The easy mtdi pump option basically.

I got it running with the new pump. Swapped out the injector on #3 to a normal TDI one and replaced the oil pump of a turbo in the back with a mk2 td one. The compressor side of it was swapped with the pinwheel and snail shell off of a Volvo Garrette  turbo. It is intercooled too.

The problem I am having is that I have to ream balls on it to get 6 lbs of boost. And even at that i can only get up to 60mph. And that is pedal to the floor. I know the wastegate on the turbo is stuck closed. But since i'm not developing boost yet i havent addressed that. My transmission code is an FN

Yesterday and today i have been messing with the pump. I swapped a 1.6 TD boost pin into it with the LDA top and spring with it. I adjusted the fuel screw up and the idle screw down to compensate for it. Tried advancing and retarding the timing too.

I thought about putting bigger injectors in it, but want to exhaust all other options with the parts I have before dropping some cash. My other thought was to take the Turbo diesel pump i have and the TDI pump i have and make a new pump to put on there so i know for sure of what i have in case the pump i am using is just a generic AAZ pump with nothing done to it.

Few other things ill add to just for more info, I have a 2.5' exhaust all the way back with no muffler that is a few weeks old. AAZ intake manifold with new gasket on it. Boost connectors are tight and intercooler appears to be good. I also bypassed it and got the same ammount of boost. The boost reading is taken from a T in the line from the LDA to the manifold and i have used 2 different gauges.

I have debated building a water meth setup for this and probably will after i get everything ironed out

Thats about all i can think of. I have tried to figure it out and read a lot of postings before asking questions, but i'm about out of ideas so i'm asking. If you guys have any ideas, no matter how obsure throw them at me. I am a VW mechanic. I have like 30 cars and more in parts so I've got a lot of stuff at my disposal. Eventually it will get a cable clutch, rod shift o2j i have sitting around as well as coilovers and an axle flip. just gotta get the motor right first.

Thanks,
Ryan

TylerDurden:
6psi ain't the main problem.  A duffer NA can best 60mph.

Any smoke? Grey or black?

What you got for compression on each cylinder?

What's the break pressure on each injector? (You can't really time with precision until the break pressures are close.)

745 turbogreasel:
Wrong spline?

thegimpster:
The injectors are stock AHU, whatever the pressure on those is. Its hard to tell about the smoke because i have been messing with fueling and timing. i want to say white at idle then none when it got warm and some black ish under boost.

My friend had a rich/lean gauge with o2 sensor that we stuck in the tail pipe and it read real lean if that helps any. I know its for gas but we thought it was worth a shot.

8v-of-fury:
Was it in the tail-pipe for idle?

A diesel cannot idle "lean" being that there is no airway restriction.. there is nothing to lean the mixture. If it injected less fuel the idle would drop. The beauty thing with a diesel is it doesn't really ever run lean or rich, even whilst puking the blackness.

Yes there is more fuel in the cylinder than can be burned, but what IS being burnt is burning at a near perfect stoich A/F mixture.

I do believe I have read the AHU stockers are 195 bar.

Navigation

[0] Message Index

[#] Next page