GTI won't start; turns over, has spark, seems to have fuel

[dcdruck]

The vehicle: 2003 GTI VR6 with 177,179 miles.

Brief description of issue:
The engine will crank away but will not start. Sometimes it sounds like it almost starts, but ultimately does not. I have confirmed spark and partially confirmed fuel.

Detailed description of issue:
A while back, I had managed to rip the wires from the plug that connects the ABS system to the front left wheel speed sensor. This caused my ABS and ESP lights to be lit on the instrument cluster. I drove the car like this for a couple months.

I was just laid off from my job last week, so I decided it was time to tackle these problems. On Tuesday, I rewired my ABS wheel speed sensor connector, plugged it back in, and confirmed that by ESP light was now off (ABS light was still on though for some reason). I then started the car to see if that would clear the ABS light, but it didn't. At this time, the car started up just fine and I let it run for a few minutes (did not drive it or move it).

On Wednesday, I tried to start my car only to find it would not start. It turned over but didn't start. Because it was the easiest thing to try, I hooked the battery up to let it charge overnight. Tried the next day and still wouldn't start. Nothing had changed between when it started on Tuesday and then didn't start on Wednesday.

What I have tried so far:

• To rule out the ABS wire that I modified, I disconnected it; same issue.
• To make sure the ABS wire wasn't shorting out, I tested it with a voltmeter; it was fine. I have pulled out the spark plugs to confirm that they are getting spark; they are.
• I checked that the fuel pump is turning on and pumping fuel; it is.
• I replaced the fuel filter and made sure fuel was making it past that; it is.
• Tried to look down the spark plug tubes to see if I could see fuel spraying, but I couldn't. Should I be able to visibly see the fuel spraying? The spark plugs smell somewhat like fuel when I take them out. I know for sure that fuel is at least getting past the fuel filter.
• Tried using my spare key in case it was a transponder/immobilizer issue.

Some thoughts I had that I'm not sure how to test:

• Could the immobilizer have been triggered? Is there some way I can reset this? (I don't have access to any fancy scanning tools or software like VAG-COM.)
• Could the timing have screwed up (and how would I test this)? I have a timing gun but it's meant to work with spark plug wires, so I don't know if it would work with my car and its coilpacks.
• Is there some way that I can confirm that fuel is being injected into the combustion chamber?

Thanks in advance for any help/suggestions.

[Holmes741]

What are the stats on the car? Year/miles etc.... Assuming it is the 24v, I think the problem might be unrelated to the work you are doing now. Since it's getting fuel, spark and cranking, I have to ask if you've replaced the temperature sensor that is notorious for breaking. It happened to me and my car wouldn't start because it was flooding the engine. This thread discusses the G62 coolant sensor and how the black one always fails.

http://forums.vwvortex.com/showthrea...24v-VR6-motors

This thread is a DIY replacement:

http://forums.vwvortex.com/showthrea...nstall-24v-VR6

If it's getting fuel and fire, there should be no reason for it not to start. Even if the problem isn't this sensor, it will be a problem eventually. Sorry to hear you got laid off and I hope this helps.

[dcdruck]

Sorry, I've edited my original post to include the fact that it's a 2003 GTI VR6 with 177,719 miles.

With respect to.the coolant sensor, that was one of the first things I had to do to the car when I bought the car, so it's already got the green sensor.



Now, just to reiterate, I'm only absolutely positive that fuel is getting past the fuel filter. I haven't been able to confirm with any certainty that the fuel is actually being injected. I tried to look down the spark plug tube to see if I could see the fuel spraying, but I couldn't tell. And I can smell fuel on the spark plugs, but cannot see any. Is there a better way to tell for sure if there is fuel actually being injected?

[orau22]

to see if you are getting fuel to the fuel rail, pull one of the fuel lines off the fuel rail, stick it in a bottle and have someone crank the car, it should shoot fuel into the bottle.

if you are getting fuel and spark the next thing I would check is if your engine crank sensor is bad, I had an issue similar to this and this was recommended to me, if your engine crank sensor is bad you will get fuel and spark but it will crank all day and not start. To trouble shoot this, IIRC you are to crank your car over and after about 2 seconds of cranking you should see your RPMs jump to 700 RPMs. If it does not do this then I believe the culprit is the engine crank sensor, if this is the case I happen to have one from my car laying around that I would sell to you.

my issue happened to be that my timing was off after I recently did a cam install. if you did not touch your timing then I believe that shouldnt be the issue.

Another question is, when you were doing the ABS sensor rewire, was the battery disconnected?

[dcdruck]

to see if you are getting fuel to the fuel rail, pull one of the fuel lines off the fuel rail, stick it in a bottle and have someone crank the car, it should shoot fuel into the bottle.

I did this and confirmed that fuel is being delivered to the fuel rail. Still unsure if it's really being injected though.

if you are getting fuel and spark the next thing I would check is if your engine crank sensor is bad, I had an issue similar to this and this was recommended to me, if your engine crank sensor is bad you will get fuel and spark but it will crank all day and not start. To trouble shoot this, IIRC you are to crank your car over and after about 2 seconds of cranking you should see your RPMs jump to 700 RPMs. If it does not do this then I believe the culprit is the engine crank sensor, if this is the case I happen to have one from my car laying around that I would sell to you.

After a few seconds of turning the engine over, the tachometer moves up to around 200-300 RPM and remains rather steady there. My Bentley manual tells me how to test the crank sensor by checking the resistance between terminals #2 and #3, but I cannot figure out a way to get my multi-meter connected to the terminals. Referring to the connector indicated by a red arrow in following image, I am looking at the correct plug right? This picture was taken from under the car, looking up at the bottom of the motor, with my legs coming out the front of the car. I was able to get the plug disconnected, but couldn't figure out how to get anything up in there to test with. I can barely get my hand in there. One thought I have is to look on eBay for a pigtail wire with the same connector on it, and just hook up that connector and use the multi-meter on the ends of the wires.

my issue happened to be that my timing was off after I recently did a cam install. if you did not touch your timing then I believe that shouldnt be the issue.

Correct, I did not touch anything related to the timing.

Another question is, when you were doing the ABS sensor rewire, was the battery disconnected?

No, I did not disconnect the battery. However, with all the cranking I had been doing to test, the battery did get really low (low enough that it stopped turning over), and so now I have a battery tender hooked up to it at all times.

Would it be worth replacing the ECM relay under the hood (the one labeled "428"), or if there is spark and everything does that mean the relay is OK? What about the other relay, labeled "100?"

[Holmes741]

Another thing to check is the fuel returning to the fuel tank. If the rate at which the fuel is leaving is the same as the fuel that is entering, your fuel pressure regulator may be bad. Doubt it, but fuel would not be injected due to low fuel pressure.

Also!!!!

http://forums.vwvortex.com/showthrea...-in-the-thread

Use this to see if somebody in your area has vag-com. I'm sure if your offer a sixer, they'll be willing to help!!

[dcdruck]

Unfortunately, I don't know what happened but I went out Friday night to try to start it because it had been raining all day, and to my complete surprise, it actually started. I left it running for about 30 minutes and then took it for a test drive and didn't have any problems with it. I then proceeded to take it out Saturday night and Monday night without issue, so I don't know what's going on with it. The only thing that changed between Thursday when it wouldn't start and Friday when it did start was the weather was about 10 degrees F cooler and it was raining on Friday. Could this have anything at all to do with it, or is it just coincidence?

On another note, I would now like to get rid of this car, so if anyone on here is interested in buying, PM me.