Hard Starting Issues in -7 C, No Codes

Hey All,

Yesterday when starting my mk4 BEW Jetta the engine failed to start the first time even after I ran the glow plugs 3 times. It started the second time but was still rough.

The glow plugs seem to be running longer than normal (7- 10 s) but there are no codes being thrown. I replaced the harness early fall with no issues. Mechanic in the summer told me that my camshaft position sensor was failing but there are no codes for it either, could that be the issue?

Any thoughts?

Thanks

My car only gave a glow plug code when 2 of em went bad. They're really easy to check with a multimeter. I believe one was open and the other ones resistance was way out of spec.

No codes means your glow plug system is working fine.

Things that could cause hard starting. Worn starter, weak battery, corroded battery wires, loose wire connections, failing cam or crank sensor, bad camshaft. Or any combination of those problems.

I replaced my cam a year and a half ago. Along with fixing a glow plug harness , replacing the glow plugs and a new starter. The weak link is the 6 plus year old battery. I get instant starts which I attribute to a large degree to the new cam.

Here’s whitedogs no start thread.

http://forums.tdiclub.com/showthread.php?t=199398

Do your glow plugs voltage match the programming in the ECU?
Some of the chain store spec charts will spec the same plug for all the TDIs and it ain't so.
For a start pull one out and see if you can read if it is 5v, 7v, or 11v.
If it says 11v it is automatically wrong and that will definitely cause you trouble. Report back what you find out.

Sometime I face this issue. First time don't start but 2nd start work! But I am thinking to buy a basic multimeter https://bestmultimeterreviews.org/ and test it.

Glowplugs are the 5v steel plugs, they should be matched with the ECU if the owner brought it to VW for the extended warranty. Battery is fine as well, I'll have to wait until the spring to check everything else for issues. Just hoping it doesn't get too cold this winter.

If they are 5 volt then it may be a problem in your cold neighborhood. That is why VW had a second recall with 7 volt NGKs and yet another ECU flash to accomodate them.


Here is a post by JSRMonster (Rocketchip Tuning) on how to identify what is in there and why it may not be doing the job for you:
http://forums.tdiclub.com/showpost.php?p=2831262&postcount=3
The links are no longer valid to the youtube videos but info is.


The recall may have expired by now but earlier on, VW was doing the reflash with new plugs free for people that complained about the issue.
If they won't do it then you can hook up with most aware tuners and get this feature done. You will have to shell out for the 7 volt plugs.

Tartrus said:

.............. Battery is fine as well,,,,,,,,,,,,,,,,,,

Click to expand...

Is it the right battery (the big thing)? If it's easy, hook it up for an overnight trickle charge next time it gets cold.

JETaah said:

If they are 5 volt then it may be a problem in your cold neighborhood. That is why VW had a second recall with 7 volt NGKs and yet another ECU flash to accomodate them.

Click to expand...

Possible, though last year the car started first try down until ~ - 30 C so I really should not be seeing a failed first start at - 7. I've been wanting to upgrade to the 7v ceramic and have been planning to get a tune so I may just couple it come spring.

Thanks for the help!

BobnOH said:

Is it the right battery (the big thing)? If it's easy, hook it up for an overnight trickle charge next time it gets cold.

Click to expand...

Hmm, I'll have to check. The previous owner started taking the car to a 3rd party mechanic after the VW warranty expired and Iv'e already found some questionable decisions made to the car. Quite possible they just put a crap battery in.

Thanks

Old battery? Old fuel filter?

Replaced the fuel filter but the car is still hard starting in the cold. I checked the lift pump while changing the fuel filter and looks like it has gone. I feel like the bad lift pump is probably why I'm having issues. Gonna replace it and see if the issue resolves.