85 Jetta needs pedal to start

Working on an 85 Jetta GL with 1.8L gas, auto trans, ac, 210,000 miles. When we got the car four years ago, it started exactly like it should - get in, turn on the key, wait until the fuel pump stopped buzzing, kick the starter, and the engine started every time (well, not every time until I put a relay into the wire going to the starter solenoid to increase the current enough to overcome the heat swelling problem). About six months ago, I began having trouble starting the car, mostly when it was warm (not hot, not cold). I could always start it, but it required some fluttering of the pedal to get things to catch. I've done a lot of stuff to this car trying to get it into better shape. When it came to me, it pinged badly, and I discovered a previous owner had removed the in-tank fuel pump and not replaced it. Putting one in removed the ping (go figure!). I did a full tune on it last summer: all filters, plugs, wires, cap, rotor, timing, etc. That sure made it run smoother. I discovered that the fifth injector was not injecting, so I replaced the sensor for it, which got it going. I thought I had the problem solved when I did that, but it still proved hard to start. I pulled the four engine injectors and replaced the large and small o-rings and the burned-up ceramic shrouds. While I had the intake manifold off (don't ask) I replaced the oxygen sensor. Now, the car has plenty of zip and moves up through the gears very smoothly; as a matter of fact, it drives almost like it was new. At this point, it starts a lot easier than at its worst, but I still have to flutter the pedal to make sure it will start - otherwise, it will crank forever without catching. It no longer seems to be temperature related. I keep it in a garage at home, but park it outside all day at work. When I get into the 65-degree car in the morning, it won't start without a little pedal flutter. When I go out at the end of the workday and start the 25-degree car, it needs a little pedal flutter to start. I seem to be able to always start the car without incident, but my wife and son have both run the battery down trying to get it going, which is why I'm still pursuing the problem. I have access to a complete shop every Friday night, with all the tools anyone could ever want, so I can check out almost anything anyone suggests (I'm auditing the open shop class offered through the auto mechanics class at the local technical college). So, the question is, what should I go after next? Pat

Reply to
pmoore44
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  1. Burn the lowest-grade fuel possible.
  2. Make sure your spark is strong and verify the action of the 5th injector again.
  3. Perhaps check the standing fuel pressure... you may have to click the relay twice before you actually crank.
  4. Crack in the coil (remote at best). Enough to bleed down on starting, but the higher running-voltage makes it do OK.

All of the above based on the certainty that the fuel-filter is clear... which is indicated by the fact that it runs well when started.

Four SWAG & Random thoughts.

Peter Wieck Wyncote, PA

Reply to
pfjw

It sounds like the cold start injector/system is not functioning. Please triple check that. IIRC the Cold start system can also function to start a warm engine. If it was functioning then the engine would at least initially start when cold. It may die out but that would be another problem. ;-) Also check the fuel distributor plate's position. I think it is adjustable if needed.

Now if the idiot lights disappear when you, or your family, cranks over the engine then you might need an ignition switch.

JMHO

Reply to
dave AKA vwdoc1

Perhaps the fuel pressure-regulator, that would affect hot/warm starting...

Reply to
al

i'd check the ( thermo-time switch ) and the spray pattern of the ( cold start valve ) and fuel pressure

Reply to
samstone

If you have all the tools I would vote for fuel pressure first. Fuel pressure guage and Bentley can help. My 84 had a hot starting problems that a "new" used cpr fixed. I also replaced the fuel distributor somewhere in the life of the car. I think I was attempting to clean the distributor and goofed somethng up. You can remove the cpr to flush out the rust stuck in the fuel screen. It costs nothing if you do not lose the copper crush washers.

Reply to
Jim Behning

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