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Author Topic: mTDI caddy up and running but not building boost or power  (Read 12167 times)

February 20, 2013, 11:57:07 am

thegimpster

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mTDI caddy up and running but not building boost or power
« on: February 20, 2013, 11:57:07 am »
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


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Reply #1February 20, 2013, 05:54:59 pm

TylerDurden

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Re: mTDI caddy up and running but not building boost or power
« Reply #1 on: February 20, 2013, 05:54:59 pm »
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.)


Reply #2February 20, 2013, 07:04:20 pm

745 turbogreasel

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Re: mTDI caddy up and running but not building boost or power
« Reply #2 on: February 20, 2013, 07:04:20 pm »
Wrong spline?

Reply #3February 20, 2013, 10:58:06 pm

thegimpster

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Re: mTDI caddy up and running but not building boost or power
« Reply #3 on: February 20, 2013, 10:58:06 pm »
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.
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Reply #4February 20, 2013, 11:01:36 pm

8v-of-fury

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Re: mTDI caddy up and running but not building boost or power
« Reply #4 on: February 20, 2013, 11:01:36 pm »
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.

Reply #5February 20, 2013, 11:02:23 pm

8v-of-fury

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Re: mTDI caddy up and running but not building boost or power
« Reply #5 on: February 20, 2013, 11:02:23 pm »
What does the exhaust sound like?? Does it go pop-pop-pop or a nice smooth idle?

Reply #6February 20, 2013, 11:47:40 pm

CRSMP5

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Re: mTDI caddy up and running but not building boost or power
« Reply #6 on: February 20, 2013, 11:47:40 pm »
???? how does a gas o2 sensor work in a diesel?? hell if that worked the EPA would love you.. they could do same tests on diesels that they do on gas cars... then places like cali would not have to exempt older diesels and such as they would have a way to test them

just sayin...

i think you rpump needs to see someone who knows what they are doing.. sadly.. 8v seems to have had a fail on his fraken m pump.. but maybe that the same issue you have that he could not resolve..

Reply #7February 20, 2013, 11:58:15 pm

8v-of-fury

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Re: mTDI caddy up and running but not building boost or power
« Reply #7 on: February 20, 2013, 11:58:15 pm »
It was a half/half for my franken pump. I got a steal on a Rover pump so I never pursued the franken pump at all.

I did an internal mod that caused the cam-plate to break off some pieces of metal and ruin my internal pressures by trashing my HP head.. SOO it was inconclusive haha.

If the pump does not have a custom modified throttle control lever.. then it will never ever perform properly. Reason being the pump will not ever be able to move the control collar far enough to make up for the DI's cam-plate with huge lift.

So if it is just an AAZ pump with DI internals and nothing was customized or modified.. you have a basic AAZ pump with 10mm internals. NOT an M-TDI pump unfortunately.

Reply #8February 21, 2013, 08:21:05 am

thegimpster

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Re: mTDI caddy up and running but not building boost or power
« Reply #8 on: February 21, 2013, 08:21:05 am »
the o2 sensor was really just an excuse to use it. he bought it last week and we were just playing with it.

The problem with the pump i have is that i dont know really what was done to it. I got it with a mk2 with a tdi in it that had a bent valve. The guy told me that he bought it off of ebay from a guy who built it for his mtdi project but never finished it. The pump was runing in the mk2 at one time and they put 50k miles on it or so over a few years.

when i have the pump more advanced it idles fine, you can drive it down the road and the turbo spools up fine, no black smoke really.

the part that i don't get is that pedal to the floor i barely get 60mph. the math doesn't add up to me that with a diesel tranny in 5th gear at at least 4k i cant do over that. My n/a does better than that.
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Reply #9February 21, 2013, 01:46:44 pm

8v-of-fury

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Re: mTDI caddy up and running but not building boost or power
« Reply #9 on: February 21, 2013, 01:46:44 pm »
The math doesn't add up to me that with a diesel tranny in 5th gear at at least 4k i cant do over that. My n/a does better than that.

Either you have a severe boost leak.. or the pump ain't what you were told it was ;)

Did you frig with it all prior to installing it?? If all the setting remained the same as the way the guys had it on the mk2.. then the pumps worthless. And they drove it as a slug..

However now that I think about it.. I am sure I was able to do better than 60mph when I had the exact same pump you have (exact same being, DI internals stuffed in to a IDI pump.. but without the proper mods.. it is still just a full IDI pump with a high lift cam-plate and 10mm plunger).

Reply #10February 21, 2013, 01:47:20 pm

8v-of-fury

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Re: mTDI caddy up and running but not building boost or power
« Reply #10 on: February 21, 2013, 01:47:20 pm »
Answer me this, is the power from idle to about 22-2300 extreme then it just drops and hits a wall????

Reply #11February 21, 2013, 02:38:48 pm

TylerDurden

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Re: mTDI caddy up and running but not building boost or power
« Reply #11 on: February 21, 2013, 02:38:48 pm »
...the math doesn't add up to me that with a diesel tranny in 5th gear at at least 4k i can't do over that. (60mph)

Ja, that sounds whack to me too... My Jettas do 65mph at ~3100rpm. The FN is not too different than the AGS & AOP I'm running.

Got teeny wheels?


Reply #12February 21, 2013, 04:42:46 pm

thegimpster

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Re: mTDI caddy up and running but not building boost or power
« Reply #12 on: February 21, 2013, 04:42:46 pm »
I've got orlandos on it which are 14's. Checked it with a gps speedo too to see how bad the truck one was off.

It sputters a bit at idle and chuggs some then when you get up into higher rpms and the turbo spools it runs pretty good and sounds smooth.

I've tested for boost leaks and cut out the intercooler and put a new intake mani gasket on it too.

Didn't mess with the pump untill the truck was up and running. then when it didn't run very well i started with adjusting the timing, then fuel screw and idle. then went to the TD boost pin, swapped the AAZ one back in today.

I've got a tdi pump laying around, if i could come up with a harness and ecu i'd just go that way. Wiring doesn't scare me I was an electronics tech for 10 years working on submarines and battle ships for the navy. I've also talked to a few people about getting a prebuilt mtdi pump too.
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Reply #13February 21, 2013, 11:55:22 pm

libbydiesel

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Re: mTDI caddy up and running but not building boost or power
« Reply #13 on: February 21, 2013, 11:55:22 pm »
I'm not afraid of wiring either, but the only thing you'll gain from doing the full electronic install is the ability to more easily diagnose the electronic parts that fail that wouldn't have been necessary if you hadn't done the full electronic install...   :P

Reply #14February 22, 2013, 12:18:38 am

vanbcguy

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Re: mTDI caddy up and running but not building boost or power
« Reply #14 on: February 22, 2013, 12:18:38 am »
I'm not afraid of wiring either, but the only thing you'll gain from doing the full electronic install is the ability to more easily diagnose the electronic parts that fail that wouldn't have been necessary if you hadn't done the full electronic install...   :P

I was on the fence about doing an mTDI or keeping the electronic stuff for my TDI build.  Then my battery died on the weekend.  I rolled the car down the hill and fired her up, then promptly started emailing people about mTDI pumps.

Then I remembered the road trip I was on a few months ago when my alternator crapped out.  Apparently finding a voltage regulator for a non-AC 1.6TD car in the US is somewhat difficult.  Knowing worst case I could just pull the plunger out of my pump?  Priceless.

I'm sure I could get marginally better fuel economy from an electronic TDI, but I'm pretty darn sure I can't just turn a couple of screws on an electronic TDI and get 30% more power.
Bryn

1994 Jetta - AHU M-TDI - Jezebel Jetta
2004 Jetta Wagon - 1.8T - Blitzen

 

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