1.6 Diesel Injector Problems

[thecheesemannn]

Hey all, New to vwvortex. I have a 1980 vw dasher diesel, with a motor from an 1981 dasher 1.6 Diesel N/A.

The car has 160,000 miles on it, and the motor has 188,000.

being that it had so many miles, and it was starting to develop some slight misses at certain rpm's, I figured that it needed new injectors.

After reading my Bentley garage manual, I determined that the injectors could be rebuilt, so i bought some injector nozzles on ebay, and changed them out.

the car started missing alot, so i did some more research, and figured out that they needed to be pop-tested, so i purchased 4 new injectors on ebay, figuring they would work fine.

the engine stopped missing at an idle, but it smoked like i have never seen before, and started missing when you drove it around.

Again, I thought that it might not be pop-tested properly, so I built my own pop tester out of a bottle jack and a glycerin filled gauge.

I was astounded to find that my new injectors were popping anywhere between 120-140bar, depending on the injector. I have been told that is too far apart, so i bought a shim kit, and tried to rebuild them. i got them all at 130 bar, and it still isnt working.

someone told me that my injection timing must be wrong, but i time the engine with all the proper tools (dial indicator and such), NOT BY EAR. my Timing is currently set to .83mm just like the Bentley manual says. It runs much better if I pull out the cold start cable, from what i understand this changes the injector timing hydraulically, not statically.

Here is my question,

Is it probably my fuel injectors? or could it be my fuel pump, KEEP IN MIND THE VEHICLE WAS RUNNING FINE BEFORE I TRIED TO CHANGE THE INJECTORS!!! (My injection pump is relatively new)

Where could i purchase fuel injectors? Does anybody have some used ones in good shape?

I have read before about aftermarket injectors (AAZ i believe).... do these fit on a 1.6D N/A? What is required to change/ what are the benefits?



There is a more detailed description of what has happened with my Dasher on this webpage

http://www.vwdasher.com/index.php/fo...he-1980-dasher

It has been 5months since this problem has developed, and I have forgotten everything that I have done since then.

THANKYOU IN ADVANCE FOR ALL YOUR HELP!

[8v-of-fury]

First step, get that timing advanced.. 0.83mm was too low even in 1981 with a brand new pump and engine.

Set it to 0.95-1.00mm and see how it likes it there. I almost guarantee it till cure the smoke, make it start easier, and unleash a little bit of power too .

[worldwide73]

Bad "new" injectors are common. If they sit on the shelf any length of time they may get mess up. I always have new ones pop tested before I put them on the car and I've found many that are bad.

[Rockerchick]

I second 8v's advice. .83 is definitely too low of timing. Get that timing advanced.

[thecheesemannn]

Alright, ill advance my timing.... I do mostly highway driving with the pesky 4sp transmission, so im revving it hard all the time. Is .93enough? Or should i go higher?

Where should i get new injectors? Anyone know of a place online? Dealership is like $250 a piece

[8v-of-fury]

Alright, ill advance my timing.... I do mostly highway driving with the pesky 4sp transmission, so im revving it hard all the time. Is .93enough? Or should i go higher?

Where should i get new injectors? Anyone know of a place online? Dealership is like $250 a piece

I suggested .95-1.00mm. Too much advance does not exist with diesels, there will be no engine damage like with a gas engine.. no pre ignition to happen as it is injected in to the cylinder.

.95mm will likely be perfect, as older pumps age they need more static advance to compensate for their wear. Try it somewhere between .95 and 1.00

[rallydiesel]

I suggested .95-1.00mm. Too much advance does not exist with diesels, there will be no engine damage like with a gas engine.. no pre ignition to happen as it is injected in to the cylinder.

Of course there can be too much advance. If you inject the diesel too early you risk damage to the rods and/or pistons. If ignition happens far enough before TDC, your rods will bend.

Otherwise, I agree with setting the timing at 1.0mm, which is VW-recommended timing for a 1.6td and would be fine on an NA as well. Don't waste your money on new injectors.

[thecheesemannn]

I dont have a set of working injectors any more, i have tried to take them all apart and pop test them myself. If i could figure out exactly how to pop test them, i would..... I built a pop tester myself, but i dont know what im looking for.

[8v-of-fury]

Of course there can be too much advance. If you inject the diesel too early you risk damage to the rods and/or pistons. If ignition happens far enough before TDC, your rods will bend.

Excuse me?

The pumps slots do not have enough movement to make injection happen THAT early.. If you start with the pump at its middle spot (like you should be with normal procedure) then you can only advance timing statically to a maximum of 2.10-2.15mm. I have tried it for myself so this is not hear say, it is my own hands on factual evidence.

2 mm BTDC is hardly injecting the diesel too early, not to mention if you ever injected it early enough to bend anything it would not run to bend anything. It would more than likely hydro lock solid on the first injection.

[GTIdaho]

I agree on advancing the timing a bit. Sometimes depending on how worn the pump is you need to play with it a little bit back and forth to make it run best and have either better economy or more power, whichever you are looking for.

As for the injectors you bought... well crapshoot there. if they are chinese knockoffs... you may not have the best results. I have only once had injectors out and tested. I took them to a diesel shop and had them test and shim them correctly. wasnt cheap but it solved a a rough idle issue I had on the car. I dont think it is something I would want to test and do at home....

[rallydiesel]

Excuse me?

The pumps slots do not have enough movement to make injection happen THAT early.. If you start with the pump at its middle spot (like you should be with normal procedure) then you can only advance timing statically to a maximum of 2.10-2.15mm. I have tried it for myself so this is not hear say, it is my own hands on factual evidence.

2 mm BTDC is hardly injecting the diesel too early, not to mention if you ever injected it early enough to bend anything it would not run to bend anything. It would more than likely hydro lock solid on the first injection.

You said you can't have too much advance on a diesel. You certainly could, of course you would have to be one or more teeth off on the injection pump gear/timing belt position. You will also prematurely destroy your glow plugs and potentially knock your pre-cups out. This will occur before you bend a rod, but both will happen when timing is advanced too far. At 2mm BTDC, your cylinder temps and pressures will be so high your glowplugs and piston crowns will be crying. And your ears will be bleeding from the injector noise.

[thecheesemannn]

Ummmmm, yeah...... I blew out a pre chaimber insert on my 84jetta 1.6 diesel, I had suspected it was because i timed it by ear, trashed the head and piston..... Thats when i went out and bought the proper tools to time them.


Please excuse my grammer, i sent this with my phone

[8v-of-fury]

Ummmmm, yeah...... I blew out a pre chaimber insert on my 84jetta 1.6 diesel, I had suspected it was because i timed it by ear, trashed the head and piston..... Thats when i went out and bought the proper tools to time them.


Please excuse my grammer, i sent this with my phone

Did you prove that it was solely because of advanced timing? No, you didn't did you. I have seen pre-cups fall out of heads that were fine and running stock timing numbers. So to say that it is fact that it causes pre-cups to fall out is preposterous.

I'm sorry but if it popped because you timed it to far advanced by ear you must be deaf... That would sound like a tin roof getting pelted with hail.

Not likely what caused your failure, and without proof.. completely inadmissible.

[thecheesemannn]

No need to get angry, i said i SUSPECTED that was the cause, not I prooved.

Furthermore, the motor was freshly rebuilt, and only had 7,000 miles on it. Im not sure why the pre chaimber fell out, i was cruising on the highway doing 60mph, on a flat. It could have been caused by a great many things.


Im not concerned with timing it, I said i will advance it, so I wil. What I want to know is what to look for during pop-tests. What pressure, and what kind of pre-leak i should be looking for.

I will try to pop test them again on sunday, and advance my timing.

Like i said before, THE CAR WAS RUNNING FINE BEFORE I CHANGED THE INJECTORS, AT .83mm timing, getting anywhere between 42.5-54mpg. Therefore, the injectors are the most likely cause of the problem, not the timing. Also, doesnt the cold start cable adjust the timing .25mm? It does run better with the cable pulled out, but still not drivable.

[8v-of-fury]

Cable only affects near-idle. Once the pump is revved at all, internal pressure picks up and takes over completely. There would be no effect to the timing if you are on the pedal at all.

Freshly rebuilt? You had the head machined I bet? That is what caused the pre cup to fall out.

You are looking for NO pre leak, and a nice even cone shaped spray. Any leaking before and/or after the injection spray is bad and will melt a piston or the head. These are not DI injectors that have a 5 hole nozzle that also uses a pilot injection. So just one concise injection spray is what you are ultimately looking for.

135 for non turbo and 155 for turbo. I think there is a 3-5% sweep for injector pop pressure variation.

[thecheesemannn]

I have been popping them at 127-130bar, with no pre leak, and your right, it does idle fine with cold start pulled, but if you rev it, it starts missing.

I have 3 full sets of injectors, and 3 extra foating around from the original 1.5L that was in the dasher to begin with.

No, the head was not machined, i had also suspected that i didnt re-install the pre-chaimber correctly. It was the first time i had ever seen that, i am used to rebuilding international engines, and thought a vw would be easy compaired to an international. I was mistaken. Tough little buggers though.....

[8v-of-fury]

You're right, it does idle fine with cold start pulled, but if you rev it, it starts missing.

Well I will tell you why, 0.83mm timing!

Way too retarded. 0.95 or higher.. It will purr. If it is too clack-clack for your liking then a pencil line movement away from the engine will probably suffice.

[thecheesemannn]

Well I will tell you why, 0.83mm timing!

Way too retarded. 0.95 or higher.. It will purr. If it is too clack-clack for your liking then a pencil line movement away from the engine will probably suffice.

they "clack-clack" alot as it is because of the mechanical injectors.... not concerned, as long as the engine can live forever. They are hard to find, and Im trying to bring the car up to show quality


My next question is about the injector heat shields...... they are new, but used. they have about 10 running minutes on them, and are currently in the engine.... do I need to replace them, or should I order new ones and wait another week? I have been told yes and no.

What torque specs should Follow? My Robert Bentely manual says 47ft/lb on the injector bodys, 50ft/lb on the injectors to the engine, and 18ft/lb on the fuel lines. are these correct numbers?

Im going to try to do this on sunday, I know a guy that will pop-test my injectors for $70, but it will take a while, and I want to drive my Dasher a few times before it gets cold. I have all the tools to pop-test them myself, I just need to figure out how to do it right.

I also need LOTS of BRAKE CLEANER!!!! lol

[rallydiesel]

I have reused heat shields in a pinch but I wouldn't recommend it. The inner cone deforms when you torque the injector. If you reuse it, it could seal improperly and damage the nozzle over time.

[thecheesemannn]

So I can use the old ones until I get it running right, and then buy new ones, and not drive it until the new ones are installed/

[fatmobile]

Reuse them.
but put a socket on one side and a ball bearing in the center of the other
before you smash with vice grips to raise the center again.

New shields will sit with only the center touching the face of the injector
and will smash down as they are torqued.

Inspect for cracks around the center with a magnifier,..
because if they are going to crack it'll be while stretching back to shape,..
not while being pressed by the injector.
Cracks aren't common the first few times they are stretched back into shape.

[thecheesemannn]

I just had 3 sets of injectors sent out and pop tested, and the guy that did it said he finished it today. I dont know if he got all 3 sets working, but he is dropping them off to me in 45 mins. Crossing my fingers, hoping it works!

[thecheesemannn]

www.facebook.com/v/506152059395095

Well, here is a video from last night. This was taken about 30 seconds after we started the engine. We were giving the engine alittle throttle to help get the air bubbles out of the system.

We hadn't advanced the timing yet during this video, it was still at the stock .83mm. After that, we advanced the injection timing to .95mm and it ran much better, however it still smokes alot. Maybe just adjust the "smoke screw" now because it doesnt smoke at an idle much.

How does one adjust this "Smoke Screw"? I have done it before, but it only seemed to change my idle.

Do you think I should advance the timing to 1.00mm? It still sounded like it wasn't running as good as it could be to me, it ran much better a year ago even with the old injectors and the stock timing.

[Rockerchick]

Video isn't working for me.

[BoostedOne]

You sure your pump seals arent starting to go?
THey wear out.. Mine smoked like a freight train, and was low on power before it died completely(not able to pull fuel to prime itself, and it would lose prime within an hour or so when you shut it off.. restarting it would take about 40 seconds if it was allowed to sit more than 15 minutes or so...)

if it isnt running as good as it was before, even with timing, then throwing more timing at it will just cover up whatever issue has you down on power...

And you can over time these things.. maybe not flat out bent rod damage, but they will run hotter.. Atleast during hot times of the year.. If you live in the tundra where it never gets above freezing maybe you can run 50mm of advance.... but down here in Florida my first diesel would over heat at highway speed with too much advance..

[thecheesemannn]

I dont see any leaking fuel, and it has no problems starting, or driving...... Its running much better now, i put some fresh fuel in it, drives fine, actually it seems better than before...... It just smokes...... Alot...... I mean it smokesALOT!!!!! I also own a Ford F250 Diesel, and it smokes about as much as my VW, And its a 7.3L!

It just doesnt idle like it used to, its much rougher, and clanky.... Doesnt really smooth out if you pull the cold start....

I can adjust the smoking with the smoke screw right? And then adjust the idle? I dont have the rpm tool for this engine, so i would be adjusting it by ear, but i think i know what a smooth idle sounds like

[fatmobile]

Yes, backing out the max fuel screw while adjusting the idle will reduce smoke.