84 Jetta 1.6td build question on performance

[1life2live]

So i have had and 84 jetta td for a couple of years now but most of the time that i have owned it, it hasnt been running. The injection pump and injectors were shot and once i had them fixed i didnt know how it all went back together correctly. I have recently got it back together with some help from a friend and in that time found this site and found all this useful info on tuning these little motors.

Now i put a new 2 notch head gasket back on with new factory headbolts and the pump and injectors are fresh. I want to get the most out of this motor with what i already have in it. Im not ready to tear it back apart and put a metal gasket and headstuds in and i dont want to tear into the pump and do the governor mod. So how much boost/power can i get out of this motor safely nad how should i go about doing it. I have already blocked off the blow off valve but it doesnt make a difference without turning up the fuel i guess. Im getting ready to install an egt gauge and already have a boost gauge in the car. Im guessing from what i have red i need a boost controller and to turn the fuel screw off. I am also going to build a full 2.5" turbo back exhaust.

What else can i do to get more power???

[8v-of-fury]

http://vwdiesel.net/phpBB/viewtopic.php?t=645

Good luck   :wink:

[1life2live]

I have read this post several times and believe i understand it. So the best option is to adjust the pin to recieve more boost? What is a safe amount of boost to run on the stock head gasket and bolts? I have read so much here but i guess i need it broken down a little. i dont understand all the abreviations and am not sure what applies to my engine and what doesnt.

[dillenger1]

over 20 would be pushing it.Block off yourwaste gate or get a manual controller if you cant trust your foot.Turn it up till the smoke gets to bad then go back a notch.You can adjust where the "on boost" fueling starts coming on,Its controlled by the smoke screw"on top of the lda"If you have smoky starts then rotate the screw counter clockwise.Do this after youve adjusted the eccentric and spring.You can also shave the plastic washer thats on the boost pin to get more travel.:I removed mine!

[1life2live]

so then 15 to 18 pounds is ok? Where is the line that i should tap into on the wastegate? there looks to be two lines a bigger one and a smaller one. and what does shaving or removing the plastic washer actually do when it gives it more travel? is it just giving it more fuel at more boost or does it feed it quicker to allow it to spool up faster. I know a fair amount about gas engines but this diesel stuff especially the idi system is really new to me and its like im reading the french side of the forum sometimes. Thanks for your patience on helping a newb out.

[1life2live]

also what are you guys setting your pump timing at? I have seen here that a couple people are setting it a little higher then the bentley says to. Just wondering if theres a benefit to my situation to do this or if its only for those really putting down some power

[vanbcguy]

so then 15 to 18 pounds is ok? Where is the line that i should tap into on the wastegate? there looks to be two lines a bigger one and a smaller one. and what does shaving or removing the plastic washer actually do when it gives it more travel? is it just giving it more fuel at more boost or does it feed it quicker to allow it to spool up faster. I know a fair amount about gas engines but this diesel stuff especially the idi system is really new to me and its like im reading the french side of the forum sometimes. Thanks for your patience on helping a newb out.

also what are you guys setting your pump timing at? I have seen here that a couple people are setting it a little higher then the bentley says to. Just wondering if theres a benefit to my situation to do this or if its only for those really putting down some power

Shaving the plastic washer allows the boost pin to push down further into the pump.  This in turn allows the follower to move further which allows more fuel to be injected.  The washer is the "stop" for the boost pin, but the stock boost was lower so to get more range out of it you need to remove / modify the washer.  It won't change when boost comes on but it will allow more fuel to be added when you are at higher levels of boost, which in turn creates more heat, which in turn pushes the turbo higher allowing it to put out more pressure, although it also can potentially raise your EGT's beyond safe levels if you start adding too much fuel.

Pump timing has to do with a few things:

- The factory timing assumes a brand new injection pump with no wear whatsoever. As the pump wears it tends to retard the timing, so more advance is needed than the 'book' value for an "experienced" pump

- The factory timing was designed to keep emissions levels in check.  NOx is really hard to regulate on a diesel and the more advance you throw at it the higher the NOx readings.  That's why the later model AAZ motors actually lock out the advance on their pumps under most "normal" driving.  More advance = better economy, better combustion, higher NOx levels...

So yes, you probably want to bump your pump timing up a bit over the stock numbers.  The "right" number for your particular engine and pump will be different than mine or anyone else's due to different levels of wear on the pump, injectors and engine.  It's basically a "try it and see where it likes it" kind of thing.  Make SMALL adjustments - like a pencil line more advance at the pump bracket at a time.

[dillenger1]

If you read up the boost diaphram(lda)gets pushed down with the pin which in turn has a pin riding on it horizentally.When it gets pushed down the pin slides down the eccentric in turn overriding the governor(throttle) plate position.when you move the pin around you can get more horiz. travel.as well as lowering the spring seat to allow it to max out quiker = more boost+temps+cylinder pressure

[1life2live]

thanks for all the input guys i really appreciate it. I want to know who of you have your own gauge to set the injection pump timing with? I bought one from prothe and its in inches not mm. I thought i had the conversion figured out but if i do then my pump timing is really out of wack. Anyone else have a gauge thats in Inches, if so what do you set it to on the gauge?

[Vincent Waldon]

And if you end up converting 1mm to be 0.039" on your new dial indicator you've got it, baby !!   :wink:

[1life2live]

Ok thanks for the info. I got an egt gauge already and am going to put it in when i build my downpipe. I did the google conversion and it came out to .039. Thanks for the picture im guessing that is showing .039 on the gauge. I think i was reading the gauge wrong so this will help ill try it when i get hame and let youo know what i come up with.

[1life2live]

well i built my 2.5" mandrel bent, turbo back exhaust and installed an egt gauge this weekend after i finally got the timing set right, i think. I drove it last nite and again this morning to work and it seems to be running good with the exception that it heats up a little more than it did before. I did put new coolant lines on it while everything else was apart so i may have an air bubble in the system. The egt gauge doesnt start reading until im driving down the road and even then it seems on the low side from what i have read here. It reads about 450 cruising and only gets up to about 650-850 under load. I know that it is still stock and with the larger exhaust im sure thats keeping it cooler but i thought it would be a little higher and respond quicker. It wouldnt matter if the probe is possibly touching the side of the manifold would it? I drilled the hole and welded the bung onto the back of the manifold but there may be a chance that it is touching when threaded in. Once i get the cooling issue straight im gonna start turning up the fuel.

Also is anyone running a high volume oil pump? My oil pressure at the head when warm is only about 15psi so i was thinking of dropping the pan and putting in a high volume pump

[zukgod1]

That sure sounds cold to me, are you sure it directly in the exhaust stream?

Mine idles @ 350-400 and runs 600-700 ish on the freeway @ 3000 rpm.
Can hit 1400 under WOT  :shock:  Wonder what it would be without the FMIC.?

Your warm idle psi is "OK" but a 36mm pump would do better.
It's an easy swap as I'm sure you know and a worthy one.

[1life2live]

yea i thought it was a little cold and yes it is directly in the exhaust manifold im just wondering if its far enoug in the manifold. with the bung and the tickness of the manifold maybe its not all the way inside. im going to order a pump then and i found out i need a fan switch as one of the terminals pulled out on mine.

How far should the egt probe be inside the manifold?

[zukgod1]

I suspect it all depends on the length of the probe?

Mine is approx 4" maybe and I have prob 3" of it in the exhaust stream at the base of the turbo.