Car won't start troubleshooting

This thread just saved my day/weekend. The TDi started hard this morning, but did start. I made it three blocks from the house before it died. Walked back home and waited for the wife to finish getting ready so we could carpool. Came home this afternoon, snagged a fuel filter after reading this thread from start to finish over lunch and started in on the job. Replaced the filter, primed the pump, filter, and injector lines, and we were off an running! I think today could have been a far more frustrating day than it was if it weren't for all of your input, especially you Whitedog! Thanks for all the great tech and support guys.

One more plug...these videos came in super helpful too. Dr. Dan has 12 videos posted and I watch all the ones pertaining to TDi's:

http://youtu.be/FAso5BG2fv0

hot starting problem

my 2004 audi 1.9 tdi pd auto will not start when hot unless the throttle is used, just bangs and rattles. it starts perfect when cold and runs perfect.

my 2003 TDI seems to have the #4 problem. Turn the key to on position all lights, glow plugs and buzzing seem to work. Turn the key to the next position and nothing.

I've had some success at getting it started every now and then if I left the key in the START position for a few seconds... but today I left it there for much longer and nothing would occur.

I've disconnected the clutch safety switch (F136) as I thought initially that maybe the caused and completed the circuit within the connector. But the issues still occurs so I know its not the clutch safety switch.

This morning however I gave it another whirl and left the key in the start position and still nothing ... but I started to pump the clutch pedal and on the 3rd attempt she fired. I believe this is the 2nd time I've seen that happen on my car.

Anyone have any ideas as to why pumping the clutch seems to allow the starter to engage? One would assume the clutch safety switch but in my case that can not be the culprit.

Any suggestion would be appreciated.

The clutch safety switch is a normally open switch that closes when you step on the pedal. Unplug the switch and jump the two wires in the connector. With the key in the start position, this will energize the J207 relay, closing the contacts to allow power to flow to the start terminal. If it now starts repeat the test a few times to verify, then replace the switch, if it doesn't start, check the relay.

Whitedog: I've already jumped the contacts from the clutch safety switch and it still has intermittent starting issues. This morning I couldn't get it started and I started to pump the clutch pedal and it fired up.

I can't understand why pumping the clutch would engage the starter.

daffy_duck530 said:

I can't understand why pumping the clutch would engage the starter.

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Because it shakes something sufficiently to make contact. Double check all of the "big" wires from the battery, and well as everything that connects to the starter.

"I've disconnected the clutch safety switch (F136) as I thought initially that maybe the caused and completed the circuit within the connector."

With the switch out and jumpered, you still have intermittant starting issues, including sometimes you can get it started by pumping the clutch. Do I have that right?

According to the diagrams I have, you could remove the J207 relay and install a jumper between pin 2 and pin 8. This will put key power directly to the starter. If you still have intermittant problems, then you need to look at the key switch or the starter.

Once I had time to take everything apart I discovered that the wire for the connector to the solenoid was hanging by a thread. It broken in my hand while I was inspecting the wire... I soldered the wire back together and issue seems to have been rectified. Luckily Volkswagen decided to give us a longer wire... almost like they knew this would happen... I'm pretty sure there was a zip tie that was used to hold all those wires together but it was broken and the wires just started rubbing and over time it frayed.

All is well once again.

daffy_duck530 said:

Once I had time to take everything apart I discovered that the wire for the connector to the solenoid was hanging by a thread. It broken in my hand while I was inspecting the wire... I soldered the wire back together and issue seems to have been rectified. Luckily Volkswagen decided to give us a longer wire... almost like they knew this would happen... I'm pretty sure there was a zip tie that was used to hold all those wires together but it was broken and the wires just started rubbing and over time it frayed.

All is well once again.

Click to expand...

Thanks for the update. I'll make sure a note is added.

Just to add another data point to the discussion:

I had a no-start situation and the glow plug and load reduction relays were working as intended. I tested the clutch switch and it was fine. I checked the wire at the starter and saw that I was getting voltage when the key turned to start.

Turned out to be a two-fold problem. First, the bendix wasn't throwing because the internal wire was cracked and not always connecting. Secondly, the big wire from bendix to starter was corroded through and had some signs of melting, so even when the bendix threw, the resistance was so high that the starter couldn't even turn, though it tried.

I could repair the wire inside the bendix. Maybe get another 300k miles out of it.

But the fat wire from bendix to starter is built directly into the brushes and holder inside the starter and I could not find a parts source for it, so I had to order a new starter. I thought about hooking up a new wire, but didn't think that even brazing on new wire would be able to carry the high amps without overheating.

So I had to get a reman Bosch unit.

Whitedog, the other thing that I noticed is that if you turn the key to the ON position and the wire to the solenoid is completely disconnected and/or broken, all the power to the instrument cluster goes off (i.e. I noticed the clock would go out, no beeps or buzzes, no glow plugs).

The reason I was turning the key to the ON position was because I needed to close my windows as it started raining. Thankfully it stopped after a few minutes.

Common rail troubles

Can anyone help me with trouble shooting the common troubles with a Common rail not starting? I know about the HPFP problems, but and sketchy about how to check for problems. Pull the filter and look for metal is one thing I know about and pulling a fitting out of the pump is another, but pictures would be good. Also, what other common things are we seeing, or do we know such as wire connectors unplugged that will cause it to not start? Anything??

Thanks.

Hi all: I am new to this forum but not new to VW Diesels. I currently have a 1999 Jetta TDI (standard transmission) with 132,000 miles, which I bought new in 99. My car starts just fine in the cold or once the enginge cools down, but once it's run for a bit it is hard to start. It takes quite a bit of cranking before the engine turns over. The dealer hasn't been able to solve and keeps mentioning cleaning the manifold (which they always do) but it didn't help last time...Any ideas?

Do you have access to VCDS? If so, check the temp sensors (fuel especially) when it won't start. Also, check the timing. Also, you should get familiar with the thread in my sig.

I would suggest getting a tune. RC1 or RC2. (Rocketchip Tuning.)
Some of those 99 models just refused to put enough fuel into the engine during hot starts, because of the ECU programming.

You could also get to someone that has a VCDS and change the coding so that thinks it is an automatic. The program for the auto allowed more fuel to be used for hot starting.

But I would go with a tune.

auroracat, we are assuming that you have an Mk4 which is the same body style as an 03. Otherwise, I think that there are some other hard start threads. If it IS a Mk4, then search for "hard start when warm" and you will get a better pictures of what is going on.

Trouble starting

I have a 2004 jetta TDI and it will turn over for several seconds or so before starting sometimes, longer when it is cold out. I read your post about the lift pump and thought that must be it. I checked it and it is coming on. The fuel filter was new 12k miles ago when I did a timing belt replacement. I will check if it is fact pumping fuel when I get off work, but if it's not I am not sure what else it could be. Any help would be appreciated. It does die every now and again just out of the blue, but it used to always start up instantly no matter the temp outside. Thanks Craig

I think that there is a link in there to DanG testing the lift pump.

another hard start hot 2006 pd

Hi, I am new to forum...have a 2006 golf pd that just cranks (like no fuel) only when hot. Checked all the forums here, traced a problem with lift pump in tank, replaced, but still have the same problem. I hooked up a pressure gauge to the port on the tandem pump. I note that pressure should be about 15psi at idle, 51psi at 1500rpm. At idle i have 33 hot, 42 cold, at 1500 76 cold, less when hot (forgot to write that one down!). As soon as i turn the key off, the pressure goes to zero. When cranking hot, the engine doesn't fire until the pressure gauge gets to about 4psi; when cold, it starts right away even though psi is at zero (until it fires, then up instantly.) My question is should there be some pressure maintained after the key is off? I understand there is a pressure limiting valve in the return line that is supposed to keep the psi at 15 at idle...i obviously have more when the engine is running, but zero as soon as the key is turned off. Between that and the pressures being a way out of spec, i assume i will need a new tandem pump?
Also VCDS shows no codes, timing at +1.5
I'd appreciate your thoughts

My apologies for my choppy writing, i'd rather talk than type!

Check to ensure that you have the hoses hooked up correctly. Trace the flow path from the tank to the filter to the tandem pump and back through the filter to the tank.

They have been hooked up wrong before.

There will be no pressure trapped in the tandem pump when shutdown.

DanG144 said:

Check to ensure that you have the hoses hooked up correctly. Trace the flow path from the tank to the filter to the tandem pump and back through the filter to the tank.

They have been hooked up wrong before.

There will be no pressure trapped in the tandem pump when shutdown.

Click to expand...

Thanks, I checked the lines and they are ok. I hooked up a pressure gauge to the other car (04), it has about 10psi (idle and 1500rpm)more than the 06. Like you said, it goes to zero on shut down. However, when turning the key to on and the lift pump starts for a couple of seconds, the pressure gauge goes up to maybe 2psi. On the 06, zero. Ten seconds of cranking hot, then the psi starts to rise and it starts.

i have a 2002 vx jetta 1.9L TDI ALH engine. recently upgraded turbo to vnt-17 while cleaning intake and egr and new bozzi nozzles. car drove excellent for a few weeks and now will not start. it sat for about a week with very little driving because i bought a the new EcoBoost!!! the temp varies from 50-75 degrees. i just replaced the glow plugs and wire harness. the ASV (anti-shudder valve) is open and not stuck closed. i started doing some test. engine cranks normal but wont start, or fire over. i pulled out my Fluke and got t testing. first thing i checked was OCV (open circuit voltage) of battery=12.3V. next thing i checked resistance of each glow plug which all of em were either .7ohms -.8 ohms. next, i checked for available voltage at each glow plug wire harness connector and say SV (source voltage). then i checked for available voltage at fuses on top of battery and all of em looked clean and showed SV. another thing i checked was resistances of each coolant glow plug. the first coolant glow plug had 38 ohms of resistance ranging to 300 ohms which is extremely excessive, while the other two plugs had right around .8 to .9 ohms. the other thing i checked was making sure the injectors were getting fuel by cracking fuel lines while a buddy cranked the engine and sure enough fuel was coming out. i also checked the fuel filter and it looked good and fuel looking clean.and the timing belt and drive belts are spinning when the engine are being cranked ANY IDEAS IM STUCK!!!?????

thanks

Was the fuel spurting out, or was it just kind of bubbling out? You don't want to loosen the nuts too much. Start with half a turn, then open it up a bit more as buddy cranks, being careful that it doesn't squirt you in the eye.

The glow plug information is interesting, but isn't really needed since the engine will start at those temperatures. The Coolant glow plugs have nothing to do with starting, just warming up the coolant faster.

yea thats what i assumed about the coolant glow plugs.just wondering. and ill have to ask my bro i know it didnt spew out , im pretty sure it was jus running out the end but not alot

i also took off the injector to nozzle line along with injector to see if maybe it had gotte clogged and left it off till morning

If you left the line off overnight, in the morning, the injection pump will be full of air and will need to have the air bled out.

how do u bleed the air?

rubadub said:

how do you bleed the air?

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The best way is to use a Mity vac hand held vacuum pump attached to the return line and pull the air out. MoGolf has a write up on how to do this. I believe that I provided a link to a bleeding procedure near the beginning of this rambling thread. Find the post about what to do if you have something open in the fuel system.

rubadub said:

how do u bleed the air?

Click to expand...

if you don't have the tool (like me) you can draw the air out, from the IP outlet with a long piece of clear hose (keeping it out of your mouth), then connect up, crack the injectors to get the last of the air out.

RE: another hard hot start 2006 pd, PROBLEM FIXED? So, i found an article about a hot hard start where the fuel was a problem....didn't figure that was me, BUT within 10 minutes of driving after adding 6 us gal of fresh fuel to a quarter tank, there has been no more hard hot starts. To be real sure, I will need another day over 70F; it has been cooler here lately.