Looking for advice N/A 1.6?

[Mathius]

Air in the little injector lines is totally normal.

There isn't much fuel flow through those lines, it's mostly the fuel that slips by the injector guts as the fuel lubricates the moving parts.

The air in the small lines may be accumulated over a longer period of time. Air in the pump gets whipped into microscopic bubbles by the whirling pump guts and those microscopic bubbles can get pushed to the injectors and get injected or work their way out the sliding injector guts.

What is key to look for, is a fine mist of bubbles in the big line returning to the tank when the engine is running, or a large bubble after sitting overnight. That indicates air in the IP. A clear line from the filter to the IP inlet is also good if you see the mist in the return.

So if there is air in the pump, then what?
Is it just a seal, or does that mean the pump needs a rebuild?
I ordered some liqui moly diesel purge. (No one sells it around here). I'll see if it smartens up my cold start issue..
I also ordered a timing tool set. Then I'll look for a compression tester.

Of course with my luck the alternator took a dump while I was out pissing around with it today.
The nickle, and diming has already begun..

[TylerDurden]

If there is air in the return line to the tank, it may be coming from the supply... a clear line from filter to IP will tell. If the supply line is clear (no air), then it's probably a seal on the IP.

WRT the alternator, the exciter wire (thin blue) frequently breaks inside the jacket near the alternator. No red alternator indicator on the dash when key is on but engine is off (prior to start) is a big clue.

You can test by running the engine and clipping a test lead from the B+ terminal (big red) to the small terminal with the blue wire. If the alternator puts out >13V (it takes a moderate rev to kick in), it's ok and the blue wire needs repair.

[Mathius]

I'm gonna have to look into my alternator issue. But it started squealing, so I think it took a dump. Dies when I pull the battery cable, and had to boost it after running it for a bit.
Someone rewired it, and all the wires are black now.. lol
But I can replace that harness with one from my parts car if I want to get fancy..

I'll add a clear line from the filter tomorrow, and see what that looks like? But I'm thinking I'm gonna have to go nuts deep into this thing. It seems to have several small issues.
It sat for a really long time in a shed. (Over 10 years).
I'm thinking I need to repair, or replace a whole bunch of stuff...

[Fatmobile]

I don't see air coming from the injectors as normal.
To me it's a sign that there is a microchannel in that injector. It slams shut but compressed air from the cylinder gets past the tip.

You need to make sure that's actually what's happening though because they start out with air in those little lines and very little fuel gets added. The shaking of the engine can make it look like small bubbles are being added.

You have a cap on one end and all the fuel flows in one direction toward the pump. The air in the line from injector 1 will pass through injector 2 as fuel coming from injector 1 pushes it toward the pump. That can make it look like air is coming from injector 2.

I had clear line coming from the pump and it kept spurting air. I thought it was from the pump until I got clear lines between the injectors and sure enough air was coming from one of the small lines between the injectors. The injector was a pisser.

I do see air bubbles in the small line going to the pump but am not sure if it's just air being displaced by fuel entering the line.

[TylerDurden]

I don't see air coming from the injectors as normal.
I had clear line coming from the pump and it kept spurting air. I thought it was from the pump until I got clear lines between the injectors and sure enough air was coming from one of the small lines between the injectors. The injector was a pisser.

I do see air bubbles in the small line going to the pump but am not sure if it's just air being displaced by fuel entering the line.

I think that's a good argument for pop testing at the earliest opportunity.

I pop test all my injectors, none are pissers and I see air in the little lines. It doesn't stream along so much, but more jitters and moves incrementally toward the tank.

There needs to be a way for air to escape the injectors, and the little ports let that happen


From: Four Cylinder Diesel ProTraining, Volkswagen of America

[Mathius]

So I have one more dumb question before I give up on this thread.
Injector breaking pressure....
I'm a cheap SOB, and all I can find for "used" injectors are turbo 155 bar injectors.
I've tried to find a definitive answer to what happens if you run them on a N/A motor, but haven't found one yet?

If I was to run them, and set the timing at 1.03 or somewhere in the same range as a turbo motor.
Would there be any ill effects?
Is there possibly a performance gain to be had here?
Would it effect fuel economy?
Or would it do nothing without a pump mod??

I have no way to pop test my 135 bar injectors without shipping them away. If I did I might as well order remans, and actually save money. Or try the 155 bar, and cross my fingers..

[colby]

Well, if you run injectors that open at higher pressures, you'd have to advance the timing some to make up the difference. I doubt there would be any real ill effects.

I wouldn't expect a performance gain though. As to fuel economy, there is one way to find out.... do it.

[Mathius]

I don't think I need to worry about anything..
Got the can of liqui moly diesel purge in the mail last night, that I ordered after I started this thread.
Ran it threw the pump like I had seen on Google, with a filter on the return line.
After about 5 minutes of running it at a high idle it started to run smoother. The rattly sound to the motor went away, and the idle actually increased.
I have to say I'm really impressed on how much of a difference it made.
Even cold starting it this morning. No cold smoke, no popping. Let a little puff of black out of it, and sat there purring.
I'm happy as a fat kid in a candy store!!

[Fatmobile]

I'm going to repeat one of Hagar's tricks for testing the breaking pressure of an injector.

When you take the 2 injector halves apart and then screw them back together; you can feel when it hits the spring,.. make a mark,...
and you can feel when it hits bottom and stops turning for sure,.. make another mark.

How far did you turn the injector between marks?
It should be the same for all injectors.
The goal is more to make them the same than to hit any special number.

I think TD injectors are louder. Lower breaking pressure means less work for the engine, since it doesn't have to pump it up so high.