Remind Me, Please! Re-entering the VW Diesel World Again.

[Oilslick]

I haven't owned a VW diesel in over 11 years. When I sold my cherry 1981 VW Rabbit back in 2005 I didn't figure I'd ever own another one. I've been driving Mercedes diesels exclusively during this time. I just traded a clunker Mercedes diesel for an '85 Jetta NA 1.6 Diesel. I think this thing will go from 0-60 in two days . I really can't remember how slow my Rabbit was. It's been so long. I'm finding it a challenge to maintain speed at the slightest incline on the road. Refresh my memory as to what I should be expecting from this car. It has a 5-speed.

I have replaced the timing belt, the clutch assembly, new axles, ball joints, water pump, strut assemblies, new rear wheel cylinders, rebuilt starter, all new engine mounts. The car sat for a few years so I replaced the fuel lines from tank to pump, resealed the IP, removed and cleaned the tank. New fuel filter, new oil filter, new oil, new glow plugs, new GP relay.

[colby]

They aren't a speed demon but it should be able to hold its own. Having said that, climbing a hill in 5th is unrealistic. You can play around with timing advance and the "fuel screw" to squeeze a little more out of it. Might not be a bad idea to pick up a set of rebuilt injectors and new heat shields as well.

I had a 91 with a performance pump on it, it made a world of difference, but you should be able to tweak yours some and get it liveable.

[Fatmobile]

Sounds like you made sure the fuel supply lines are free flowing.
Did you get rid of the water seperator?

I remember taking one up to 80 pretty easy.

Clear fuel lines in the engine bay?
Accelerator lever goes all the way to the stop when you floor it?
Where is the max fuel screw set?
How did you set the timing?

[Oilslick]

To answer the question regarding how I set the timing. I have all the timing tools from years gone by so I set it according to the Bentley manual. I used my dial gauge to set the injection timing. Everything came together nicely. I haven't tampered with the fuel screw to juice it up.

There are times when I'm accelerating that it feels as if a Turbo kicks in...and this is NOT a Turbo engine. It's like the engine frees up and I feel easy acceleration. Most times the engine seems to be governed like an old 2 stroke Detroit. It just hits an rpm and stays there. It doesn't gain nor does it really lose speed. I can run 70-75 mph on a fairly level highway with and occasional visit to 80 mph. The engine is tired though. The blowby is quite impressive at 248k. There's no excessive smoke while driving. She cranks up clean and runs smooth and evenly. I want to venture into a valve adjustment and I may try to replace the rings in time to come. I just would like to know why the free and open feeling at times when accelerating and then having that governed feeling at other times.

[colby]

I'd run some lubro moly diesel purge through the pump. A lot of it, clean her out. Couldn't hurt. Sounds like something is sticking in it.

[sgnimj96]

I remember taking one up to 80 pretty easy.

Clear fuel lines (even just temporary vinyl ones from home depot) will tell you if air bubbles are going into the IP and messing up youir fuel pressure.

Normally, ou should see some black smoke if you floor it to a high rev.

After you get your fuel delivery issue or really bad timing fixed, you can work on adjusting the pressure regulator on the IP for proper advance.

[TylerDurden]

Hate to be the bad-news guy, but...

I'm going with the 250k miles blowby . That's the age when the rings go. Low compression can lead to low torque, IMO.

It's been awhile since I've driven an NA up the Kentucky highway hills, but I recall a good engine can pull a Jetta up in 5th gear, unless the car is heavily loaded.

[Oilslick]

The bad news is taken well. I was leaning toward that being the overall reason for stagnant power. I plan to have the head redone and I'll just replace the rings at that time. This is my "fun" car, so it's not earth shattering if it needs rings. I'll tear it down in a few days and see what I can see. Thanks!

[sgnimj96]

Compression Test - Harbor Fright sells a cheap one, I know it works for the injector hole but I don't know if it has the glow plug adapter

You might even be able to "borrow" one from the autoparts store

[Oilslick]

I have a diesel compression tester kit. I just haven't taken the time to test it yet. I'm installing a clutch kit into a Mercedes 190D presently so the Jetta is being ignored for the moment.

[Fatmobile]

You only answered one of my questions so I'll respond to that.
I don't like the official dial gauge method of timing the engine.
It just gets you in the range, doesn't set it where it runs best. That takes testing and adjusting.

[colby]

For what its worth, I had one with around 300k on it and had a tremendous amount of blowby.. so much so that it blew the intermediate shaft oil seal out and emptied the base while going down the road. Oil pressure light came on, whole side of car soaked in motor oil...

Put a new seal in, with a new timing belt, and the rest of the oil seals and ran a piece of heater hose off the valve cover breather down behind the transmission. Never had a problem again. It had plenty of power. It started hard, but once it was running, it really ran well. I was running a 1.5L 107A bosch pump on the engine which apparently had a bit more timing advance than the 1.6 pumps.

Fatmobile is correct in my experience. I dial gauged one but it ran crappy. I tuned by experimentation, sound, etc. Always ran better that way. I'm willing to bet your pump is somewhat retarded and advancing it a bit more will get you some of that lost power back, but the sudden surge of power is concerning. I don't know enough about them to say for sure but it sounds like something is sticking in the pump. I'd still run some diesel purge through it. We did on a mercedes, the diesel purge turned black almost instantly. Did a few treatments, and a crap ton of lost power was restored.

[Oilslick]

As far as the timing, I have timed them with and without the dial gauge. I timed this one by ear at first and wasn't satisfied so I used the dial gauge. A compression test yesterday revealed the real problem I do believe. Cylinders 1,2, and 4 have 22 bar (320 psi) while cylinder 3 has around 14 bar (200 psi). Cylinder 3 also has plenty of oil in the prechamber. The injector tip was dripping oil when I removed it. The engine ran smooth in this condition however. I'll be tearing it down this week to see what I can see. At minimum it will get new rings and rod bearings if the cylinder bores are reusable without having them machined. I'll have the head inspected and give it what it needs.

With regard to diesel purge, I ALWAYS use diesel purge on any new diesel I acquire. That is the BEST system cleaner that can be bought, IMO. I wish this was an issue that could be resolved with diesel purge.

[Oilslick]

Well, I removed the head and the oil pan. I pulled piston #3 and when it came out one of the rings fell out into cylinder #4. There are vertical scratches in the cylinder. They're not deep, but scratches nonetheless. I'm not gonna invest much into repairing it. I'll just hone the cylinders, install new rings, and run it. It may last a few minutes, a few miles, or run forever. Maybe it'll run long enough to drive it to the scrap metal yard. I'm just having fun!

[colby]

You could dingleball hone it, Roadkill style.