First start after 25 years - problems Options

[spencercanon]

Hi all this is my first post here! I recently picked up a ’75 1.8 that was last registered in 2001! Pretty good barn find, in my opinion. It was up in the high desert of California, so no rust, great mechanicals, all the electrics work. Just flaking paint, decayed interior …and an engine that probably hasn’t run since the Clinton Administration.

The TLDR is the car has started and run for 10 seconds but now won’t start at all.

A quick timeline of what I’ve done/tested:
- Dropped the engine, adjusted valves (encountered something strange that I’ll ask about later)
- Old starter could barely turn the engine over. Replaced it with a hi-torque.
- good compression
- Replaced the old broken bellows thermostat
- New fuel lines, vac lines, spark plugs and wires
- deleted EGR system
- Fuel pump was getting power but dead - replaced it.
- Coil’s good. Cap and rotor look good. Points gapped.
- The L-Jet AFM had been opened and the adjustment wheel inside was so loose that it the flap wasn’t closing fully so the pump was running continuously. I rotated the wheel until there was enough tension to turn off the fuel pump. (I would have normally never touched the AFM!)

Put the engine back in and the car started on the key immediately, ran for 10 seconds and died. I tried again, it started and ran for 5 seconds, then popped loudly back up the intake with enough force to blow the intake boot off the AFM. Since then, it hasn’t started.

Couple notes:
- after the pop, I felt like the intake pipe connector hoses were probably leaking, so I put hose clamps on them. With those clamped down and fresh vac lines everywhere, I’m pretty sure there aren’t any more leaks.
- oil filler breather nipple broke so I’ve taped it off until I can get a new one. But I’m not sure how this affects the vacuum… should it be left open for now?
- I don’t know the fuel pressure but it does have a new pump and lines so I’d be surprised if pressure is the problem.
- tested injector ballasts and got correct ohm readings
- It did start and run on its own spark and fuel, so I assume ECU and injectors are OK.
- the AFM is obviously an issue … probably considerably off. But again, the car did at least start a few times.

So now what?
- I’d like to check/test anything I can before I start buying replacement components.
- Are there baseline settings for idle speed screw, and at least a “best guess” AFM setup?
- Should I just buy another AFM now, knowing this one may never be right again?
- could the intake backfire have damaged something?

Thanks in advance for your thoughts!

[technicalninja]

You're good. Make sure the valves on cylinder#3 are under load (slightly open).

Now, if you really have hydros in there, you're going to need to research exactly how to adjust them.

It's NOTHING like mechanicals...

When I have no procedure, I'll take one apart, clear all of the oil out of it and "plot" it's total available travel from push rod contact until it goes solid.

Count the number of turns/degrees at the adjuster.

Then I'll choose a point 60% of travel from solid and try that.

That will usually work with most hydraulic lifters, but I'd do a bunch of research before going with my "gut". I'd also want to verify the "published" adjustment procedure placed the adjustment somewhere in the middle of the range anyway.

I'd REALLY want to find out anything I could about the previous owner who had the engine done. I'd want "history" on that badly.

There is a small chance it could be good stuff...

[spencercanon]

I'd REALLY want to find out anything I could about the previous owner who had the engine done. I'd want "history" on that badly.

I'm VERY curious as to what's been done to the engine as well! I do know that the PO autocrossed it at some point. A few SCCA ribbons and some magnetic numbers were in the trunk. Unfortunately the previous owner is now very elderly was unable to provide any detail. The car was stored in a garage in Big Pine, California. An area that gets only a few inches of rain a year so the perfect place to store a car. However, it's also an area where there are a lot of people who can build an engine, but few who would have known the ins and outs of a VW engine... so I don't think I can fully trust that it's been rebuilt properly.

Thank you again for the suggestions. I will certainly research the lifter adjustment.

For the fuel flooding, I realized that the #4 cylinder probably flooded because its intake pipe was the lowest point of the plenum. So the cold start injector is probably the culprit for all the flooding. And I suppose all I can do about the distributor orientation, is swap the plug wires around. With all those issues addressed, I'm feeling cautiously optimistic that the old girl will fire up!

-Spence