1998 jetta gl 2.0 liter cranks won't start

[Elciteeve]

I just purchased a new (to me) 1998 Jetta GL 2.0 liter that cranks but will not start. The previous owner had the vehicle "Stop starting" and attempted to fix it by replacing the ignition switch, checking / replacing all fuses, tested fuel pump (tested good pressure so did not replace) replaced all vacuum hoses and replaced the battery. One year ago the distributor, spark plugs / plug wires were replaced and the starter motor checked and tested good.

This was all the information he had to offer and since then I pulled the wire off the coil and didn't see any spark so I replaced the coil (having seen a crack in the case I decided if that wasn't the problem, it would probably be an issue in the near future) I tested all the fittings of every wire I could think of to make sure everything was securely connected. I re-checked all fuses and they all looked good.

I think I've narrowed my problem to a relay or the ECU. Before I go searching for a new ECU I just wanted to check the relays.

According to all the images I've been able to locate it seems like I'm missing the digifant relay. (supposedly the digifant relay resides in the #3 location which as far as I can tell is empty)

Am I reading something wrong here or is there simply an entire relay missing?

Any advice or additional information would be greatly appreciated.

Other things to note:

The engine cranks over strong, the check engine light is on with the key in the accessory position, or in the on position. The engine doesn't even attempt to fire, it just cranks away. I pulled a spark plug and there is fuel on it, so the fuel pump seems to be working. The plug itself looks good, and has the gap set correctly (.024") everything on the car seems to be in tip top shape accept that it won't start.

[vwnutts]

Probably the crank sensor, front of block to the right of the oil cooler. Held in with an Allen head bolt, takes 5MM Allen key to take it out. Has one cable going to It, should have off white connector on the end.
_________________
1970 std beetle, 1991 2 door Jetta (Best 1/4 mile 10.21@147) still a street car, 2001 1.8T 4 door golf, 2001 1.8T Jetta Wagon, 2009 TDI Jetta, 1999 F350.

[Elciteeve]

by the "crank sensor" are you referring to the "camshaft position sensor/Hall sender?"

[ps2375]

your car is not a "digifant" car, it has motronic management. Have it scanned for codes, much better than searching for pictures on the interwebs. And a Bently manual will give better info than pic searches.

[ps2375]

[Elciteeve]

I have a chilton manual that came with the car but it seems to be nearly worthless compared to a bentley... I've had the car for 7 days now... I think I'm way over due to procure the bentley for it.

Thank you for the info. I'm very new to water cooled VWs. My only other VW I've owned is my '71 westy.

[Elciteeve]

From what I can tell you are referring to this:

The other end goes over the top of the oil cooler, then back under the filter and plugs in the the block just above the oil pan, only I don't see an allen bolt holding it in place, it just seems to plug in to the block.

I can't get a good image of the other end of the cable.

[vwnutts]

That's the connector, the bolt is around the 1 or 2 o'clock position, might even be a bolt that takes a 10MM wrench to remove. If you can get it scand it should show what is keeping it,from starting, the security alarm might be doing it.
_________________
1970 std beetle, 1991 2 door Jetta (Best 1/4 mile 10.21@147) still a street car, 2001 1.8T 4 door golf, 2001 1.8T Jetta Wagon, 2009 TDI Jetta, 1999 F350.

[Elciteeve]

I had the car scanned and it didn't show any codes. But the check engine light is on.

[ps2375]

If motor is not running, CEL will be on. Have you verified: spark, fuel, compression and engine mechanical timing(cam to crank and dist)?

[Elciteeve]

fuel pump tested good for pressure and when I take out a spark plug there is fresh fuel on it. I can also hear the pump when I initially turn the key on. My multi meter reads out that there is voltage getting to the spark plugs. I haven't done a compression test, but it sounds like there is good compression.

The fact that the car was working perfectly, and then just stopped suggests to me that I don't have a mechanical problem, but an electrical one. There are also no odd noises being made when trying to start the car, and apparently there were no unusual noises before the car stopped running nor when it quit working initially.

I pulled the wire from the distributor and cranked the engine over to see if I was getting spark and I didn't see any spark (I'm not sure if this method will work on this vehicle, I've done this on older cars and it worked) So I thought I could have a bad coil, but I replaced the coil with a new one and the car still won't start. I just checked the spark plugs for current though, like I said, and there is current flowing to them.

[ps2375]

[Elciteeve]

Well I changed the crank sensor and the vehicle started effortlessly. At first the exhaust smelled a bit rich, but after it warmed up it seemed ok. I'm guessing all the attempts to start the engine with fuel being injected in and then not burned made the initial fuel mixture too rich.

The engine sounded totally normal, ran for 5 minutes and then I shut the engine off to see if it would start again. (The previous owner said he replaced the ignition switch, which appeared to fix the problem for a few days, then it wouldn't start again)

I can no longer get it to start so I'm starting to narrow the possibilities now. It has to be the ecu, right?

[ps2375]

[Elciteeve]

It seems like signs lead to the ECU being the problem though, doesn't it?

[ps2375]

What have you checked?

[Elciteeve]

Here is what has been done so far:

Checked all fuses
Replaced fuel pump relay
Replaced ignition switch
Replaced all vacuum hoses
Tested fuel pump pressure
Replaced crank sensor
Replaced ignition coil
Replaced battery

When I replaced the crank sensor the vehicle started and ran fine. So I assume the timing is correct. For some reason the vehicle won't start now though. To me this sounds like an ECU problem, or possibly a relay. I have the bently manual now and am scouring that for information, however I still can't find a list of which relay is which. (That is to say, the bently has an image of what I have been able to find online, which is obviously different than what my relay set up shows. Since the bently lists the #3 relay spot as the ECU relay which in my vehicle is empty, as shown by the image above, the vehicle wouldn't run without the ECU relay however, so I still have no idea which relay is for the ECU, which seems to me to be quite possibly the issue.)

[ps2375]

What have to checked since it ran and then won't start. All the stuff you checked before it ran is irrelevant, check it all again.

[Elciteeve]

[ps2375]

When you do the clutch, get a manual adjusting clutch cable, the auto-adjusting ones tend to fail and cause the push rod to slowly machine its way thru the thrust plate. Actually, I think they do this without even failing.