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Discussion Starter #1
I am new to the forum and I have been working on my beetle for a few weeks. The problem started with my son driving the car with a check battery light on. (error #1)After it stopped running, he had it jump started by one of his friends (error #2). I towed it home and charged the battery, which seems to hold a charge, but the car would not start after that. It does crank and seems ready to start, but then doesnt. Assuming an electrical issue, I plugged in my VCDS, but get no error codes. The glow plug light comes on briefly, but it is warm here in NC, so that is no surprise. I did replace relay 109, but no luck. I do get fuel at injectors with connector cracked, shutter valve is open, MAF reading is high without the engine running, but no difference with MAF plugged in or not. Engine speed sensor tests normal at connector and when cranking, the VCDS displays normal cranking engine speed. Throttle position sensor displays correct position with the VCDS running. What haven't I checked? Where to go from here?
Thanks for any help.

Don
 

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What about leaving all the injector line cracked open just a tiny bit at the injectors then having someone crank it and as it starts to fire close each pipe one by one, the other thing you could try is disconnecting the coolant temp sensor plug, that'll force the glow plugs to work for longer.:)

welcometomyturbodies
 

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Fuel, compression, and air. It is most likely not compression or air.

Can you see injection timing through VCDS engine measuring blocks? I've never tried this on an engine that wouldn't start but it's possible the fuel is being injected at the wrong time and causing the no start. Also, since this is a technical thread beyond an intro, moved to mk4 section,.
 

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Discussion Starter #4
I had an assistant this morning and I have now tried cracking the injectors as suggested, still no start. It really teeters on wanting to catch, but no luck. I got a fair bit of diesel spray from the individual injector connections. I watched the VCDS during cranking and the injection timing that is considered the norm, is 11degrees BTDC. According to the VCDS monitoring, injection is starting at 0 degrees BTDC, clearly too late in the cycle. The MAF, during cranking clearly reads correct flow and the speed sensor clearly reads 280-310 RPM. I see injection quantities of 34 (sorry didn't note the measurement value), but this read as normal.

I did try tapping the throttle a couple of times (I know there is only an electronic connection) but clearlly the throttle measurement block senses the request and two times (who knows if associated with the throttle or not) there was a one second or less beginning of an idle. The speed sensor hit 1000 RPM for that moment.

So, the only thing out of norm is injection timing. How can I adjust this, recognizing that before the dead battery/warning light issue, the car ran great.

Don
 

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Put the engine to TDC and check a few things: is the timing belt tensioner about right? The dash will move with age and temperature. If it's slightly off, don't adjust it.

Is the camshaft slot about horizontal? Is the injection pump hole about where it should be? This is just a quick check for timing. See the timing belt writuep in FAQ for more.
 

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Finally, I had some help again today. Wow it is impossible to turn the crankshaft and look at the flywheel at the same time! With flywheel at TDC, the hole for the diesel injector is not lined up. It is about 10 degrees (guess) back from where it is supposed to be (lining up with the small block on the injector pump). That is consistent with what the VCDS shows me when cranking (11 degrees BTDC). I am perplexed. The timing belt is only about 3,000 miles old. The remainder of the tensioner, etc. looks fine. The teeth on the belt are not particularly worn, nor are the pullies themselves. I still harken back to, this all started with a dead battery. What am I missing?
 

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Have you checked the intake to make sure the anti shudder valve is fully open? I've read of that causing this sort of problem too. With the battery light and everything I completely got thrown off course, I just remembered about checking all the basics first. So we know it's getting fuel, the chances are the compression is fine which leaves air, is it getting any? I've seen these cars start with the timing way off but they tend to just run really bad but hey do start usually so check the ASV is wide open.:)
 

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Discussion Starter #9
Put the engine to TDC and check a few things: is the timing belt tensioner about right? The dash will move with age and temperature. If it's slightly off, don't adjust it.

Is the camshaft slot about horizontal? Is the injection pump hole about where it should be? This is just a quick check for timing. See the timing belt writuep in FAQ for more.
Ok. So forgive the last newby post. I reread the timing belt FAQs and realized I was 180 degrees out. So, I rotated 180 more and lo and behold at TDC the pump and cam are in correct position. The pin fits right in the hole of the pump and is lined up perfectly and the cam slot (vacuum pump end) is horizontal. In addition, the timing belt tensioner is in the correct place. I did check the ASV and it is wide open, though there is some carbon buildup, but not an unbearable amount.

Am I at the place where I need to try a new ECU? Since there are no faults yet no running motor? I am somewhat perplexed since the VCDS does see many of the appropriate measuring blocks. Can the ECU still be dead when that is the case? Again, thanks for all of your help.

Don
 

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Discussion Starter #10

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This is the part I was thinking of, the lever thing on the side controls the asv and the one on top does the egr. If it looks all clear and that flap is fully open it might be worth pulling the intake pipe off the manifold and seeing if it starts just in case there is anything wrong with the air side of things.:)

 

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To summarize where I am at: I have verified the pump timing at TDC, checked the shutter valve and it is open, replaced the voltage regulator and verified (bench tested) the alternator, repaired the pressure relief valve in the pump itself (the piston was out of it), and checked the fuel filter to make sure it will pull through and drained it to make sure there was no water AND that the car has diesel fuel in it, used a hand vacuum pump to pull fuel through the fuel pump, verified all of the vacuum lines are connected, charged the battery, but the car doesn't start. I even removed the bunged up right side cooling fan that was cracked and disconnected the plug, just in case there was some unusual electrical signal coming from there.

When I tried to fire it the last time, I loosened the injector connections, but got no fuel from them, which may have to do with disconnecting the fuel filter. what am I missing?

Don
 

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Discussion Starter #13
Ok, so I pulled fuel the rest of the way through the injection pump and now have fuel at the injectors. After battery charges, here's hoping!
 

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Still no fire, but turns over great and every now and then a spark of a maybe it will start...but not so far. I am going to do a basic thing too...replace the fuel filter just to be SURE that it is not restricting fuel flow...even though this ALL goes back to electrical problem.

Is it reasonable to assume (knowing the implications of that word) that the ECM is okay given that I get readings from it on VAG COM? no faults and good reading blocks. I tried to find a used ECM at the local junk yards...I mean used car parts places...but no such luck. Is there some way to test this thing to KNOW that it isnt the source? Insert frustrated scream here...there is no good smiley face for that.
 

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some new information. I opened the dash, just to see if there was an obvious problem with the ECM (puddle of water, overheated wires etc.) unplugged it and plugged it back in.. changed fuel filter because sometimes simple things right?

Now when I try to start...notice try..not succeed, I have four faults on the VCDS:

1) 00532 SUpply voltage B+ implausible signal intermittent 27-10

2) 01237 Vcds lite will not decode 31-10

3) 00519 31-00 vcds lite will not decode

4) 00527 (G72) intake manifold temp sensor 30-00 open or short to plus

I still get readings across the measuring blocks and on group four, it still says my specified start of injection is 11 degrees btdc, but actual is 0 btdc which corresponds with the norm. I still wonder, is my ECM screwed up??
 

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Well, the good news is that your 98 doesn't have an immobilizer so if you can find some place to swap it, to test it, it is plug-play. It could be broken wiring or corrosion.
 

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Ok. so here is...the rest of the story. My ECM was in fact good. A local diesel mechanic checked it out. He jumped in where I had left off and found the thing I didn't know about...no fuel cap....Oh yeah Dad..I did lose the fuel cap. SO, after replacing the voltage regulator and putting the thing back together, what the mechanic found was a leak in the fuel pump. SO, despite starting with the bad voltage regulator, the moral of the story is that it is the red herring that you didn't know about that causes the continued problems. Now with a resealed pump, a new fuel cap and a new voltage regulator, we are back on the road. Thanks for all of your help and suggestions throughout this.

Don Winters
 
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