No-Start Conundrum (ALH)

[shadows]

My car won't start and was hoping the community could suggest where to troubleshoot next. What follows is a rough breakdown of my efforts so far.

Car was struggling to start for awhile now. Took the battery to AutoZone and it tested as bad, replaced on warranty. Starting improved, but was not fantastic. Car barely started (slow cranking) at 17°F with battery voltage at 12.1V. Drove to my GF's and the car was running fine, but now after sitting overnight it cranks without starting (22°F) even with booster box. Applied a trickle charger to keep battery fresh during subsequent attempts.

Info from various attempts:
Ambient Temperatures: 17 - 40°F
Battery Voltages: 12.55 - 12.1
Battery: Duralast Gold 94R - 985CA, 790CCA, 130Ah Reserve
Starter: Autozone, a few years old
Voltage Drop (to starter): about 0.79V and 0.75-0.82V with a newer clean cable from junk yard
Voltage Drop (to block): 0.1V
Glow Plug Ohms: all four at 1.8 Ohms
Glow Plug Voltage: battery voltage
Starting RPM (VCDS): 100-185
Fuel cutoff: Actuates with key on
Fuel Line: Bubble about 1.25 inches long
IQ during cranking: 29.5-35.4 mg/s
VCDS Injection timing: Dead middle of graph as-of a few months ago
VCDS DTCs: None relevant
Oil: 0w40 Liqui-Moly Synthetic
Mods: EGR/ASV deleted, Kerma tune, R520 nozzles & 17/22

If anyone has any suggestions of where to look next, I would appreciate it.

[[ SOLVED: ]]
I'd lost prime on the fuel system. There was a bubble at least 1 inch long in the sight tube and I couldn't see fuel in the filter which was a good indicator. Futzed with the thermostatic tee and rebled the lines to get it running. Also refreshed battery/starter/glowplug electrical connections for good measure.

 

[oilhammer]

Does it seem like it is cranking slow to you?

I would not buy anything from Autozone, especially a starter. I'd put a genuine Bosch reman on there. But only if you feel like it is cranking too slowly. Still, an ALH even with a slow crank usually will start. You may have a loss of fuel prime (leak in the system, bad pump, etc.)

 

[shadows]

I agree about avoiding the autozone starter, but I was not as financially sound at the time it needed replaced and the lifetime warranty was too tempting.

With the battery charged, it may not have been turning over as quickly as it could have, but faster than other times when its started. Usually if it's barely rotating it will accumulate a few stumbles until its idling but this isn't happening this time.

There's a bubble a little over 1 inch long in the line to the fuel pump. I've not been able to observe it while cranking yet.

 

[shadows]

Unfortunately I marred the threads on a glow plug while inspecting it, so it will be Sunday before I can continue to test cranking.

 

[kiwibru]

How is the IP ? tight no leaks? Still using OEM fuel filter set up and thermo-T?
That bubble is troublesome to me. Air in the system. A small bubble is normal on some of the ALH engines. Is your fuel filter low miles? Running anti-gel in your fuel?

 

[steve6]

How's the timing belt?

 

[turbovan+tdi]

Does the GP light come on? Check relay 109? The air bubble isn't right, you might have an airlocked IP.

 

[sisyphus]

Remove the battery and have it load tested. Voltage means nothing without resistance applied to it.

 

[SparkyWagon]

that definitely sounds like starter to me. mine would slow start for a year and a half. if i didn't plug it in during the winter and it fell below 20 degrees it didn't want to do anything at all. i know BOSCH is the best but at the time i didn't have the funds for one. NAPA had the best deal with the lowest core charge too. 105 bucks i think, roughly 20 core.

it never started so fast since since i owned the car.

also the bubble in the line seems like enough air to not start anyway. just had this happen on my brothers tdi for no apparent reason. lost prime. so try cracking the nozzles first (cheap easy way first) if you have solid fuel flow get a new starter if it doesn't start

 

[shadows]

Never had any IP issues. No codes, no leaks, always good power. Just over 200k on engine.

Fuel filter is an adapter that preserves the thermostatic T for the CAT 2 micron filters; made by a forum member back in the day. Filter is about 1 year old. I replaced all the o-rings and used fuel resistant sealant as extra protection, though I never could get it to stop bleeding back slightly. This bubble is larger than I've seen in the last year, though.

I use Power Service Diesel Kleen in the summer and their anti-gel in the winter, but it even was failing to start well above freezing.

Timing belt isn't due for replacement and appears to be in good condition.

I'll check the fuel priming and flow tomorrow as well as get the new battery tested to see if it was somehow faulty. If that yields, I'll consider a new starter, though 200 rpm seems like it should start if everything else is working properly.

 

[sisyphus]

The battery and the starter are pretty closely related. I had it explained to me once here somewhere like this: If the battery is indeed sub-par, the starter draws too many amps out of it and more or less the windings in the starter suffer as a result, basically damaging the starter and aging it prematurely.
Anyway that's the way I remember it.
Also IIRC the engine needs to turn at about 300 rpm before it gets enough compression to start.

 

[KLXD]

What did you do to the plug threads and how are you going to fix them? A back tap I hope.

A 1" bubble in the line is normal. Mine usually has a bigger one than that.

 

[Ski in NC]

If after cranking for a good period with no start, say a total of 15sec, it should be showing fuel vapor out the tailpipe. If no smoke, engine is not fueling.

Also check that the anti-shudder valve is not hung closed. That little beast has fooled a good number of folk. ASV stuck will keep the fuel from showing out the tailpipe, too.

Glowplugs can be tested without removal. Just put power to each with harness off and if you get a little spark, it is not burned out.

 

[UhOh]

Starting RPMS 100 to 185?

What's the tach showing?

I replaced the starter in my wife's car which was only spinning around 18- RPM. New (cheap- I'm going to rebuild her original one) starter and it spins around 250 RPM. The battery had checked out and I'd cleaned up the battery grounds, though they were actually perfectly fine.

Check ASV isn't sticking closed: I believe that if it's closed the engine will actually crank easier, but, of course, it won't start. Hopefully your IP is OK. Might check that you're getting 12v to your fuel shutoff solenoid: if you disconnect one of your injector lines and crank a bunch if you get next to no fuel then this might be THE issue.

 

[shadows]

Wanted to provide an update. We got it running!! Starts faster than it has in a long time now.

The biggest component, was a lack of fueling. Couldn't see fuel in the filter even after pouring a bit more in. We bypassed the filter briefly, bled the hard injector lines and it started fine. Hooked the filter back up, reseated the Thermostatic Tee, and it runs fine with no bubbles in the fuel line. I can only assume a bad seal on Tee had let air into the system.

For the glow plugs, what I had thought was borked threads in the head turned out to just be carbon build up. An M10x1.0 tap used as a thread chaser solved that.

Many electrical connections around the battery, starter, and glowplugs were cleaned and greased. Voltage drop is now lower. Starter is still Autozone for the time being.

 

[shadows]

If I installed an in-tank lift pump would it avoid any issues with the Thermostatic Tee?

 

[BobnOH]

Don't know.
Have you tried putting like 5 gallons of diesel in the tank?
Maybe a small bit of debris in the tank is partially restricting the fuel pic-up.

 

[kiwibru]

The lift pump can help fuel delivery but it can hinder if you have a leaky Thermo-T O-ring. It will certainly help prime the system if there is a leak but it will not fix the problem. Those O-rings need replacing now and then or they will eventually leak enough to create a problem as you discovered! I have lift pumps in both of our cars. One car has fuel system using the T with CAT filter. The other car does not as I run an aftermarket filter that has a return connection direct to the fuel tank, no T. Fuel filter swaps are very easy with the lift pump in the circuit but I always fill the new filter with fuel before spinning it back on then let the lift pump circuit do the rest.
Highly recommended mod.

 

[shadows]

It's almost 60 out today and the car had been sitting for a day or so. It cranked and cranked before finally starting. That thermostatic tee can't arrive quickly enough! Sure hoping the fresh o-rings solve the problem for good.

 

[shadows]

I wanted to give a final update. I am working properly after more rounds of trouble.

The brand new Thermostatic Tee arrived a few days ago. I swapped it in and started the car, but it was sucking NO fuel from the tank and just draining the filter. I futzed with the old Tee using sealant and grease and it drew much better but there were still bubbles between the filter and pump.

A couple days later, it wouldn't start again and had lost prime to the injectors. I had a vacuum pump this time but could not figure out where air was leaking in. I ended up replacing the whole unit with a new OEM filter and the new tee. After bleeding the system, it starts on 1/2 a crank and has no bubbles between the filter and pump. I will run with this until I can figure out the advanced filter off the car.

 

[shadows]

Can anyone with more experience speak to how necessary the thermostatic tee is in the US climate (Ohio)? I'd prefer to delete it and save the trouble if it's not necessary.

 

[gatz]

I've been running about 2 years with the Kerma widget tee delete in New England weather, no issues. If there is any difference in warm-up times I cannot tell.

 

[gatz]

Oh one thing with the Kerma Widget though, it didn't come with the right size O-rings. I had to pull the ones off the old tee. They're normally included with new fuel filters anyway.

 

[whitedog]

Sounds like the water drain valve on the bottom of the filter may have been leaking.

 

[wonneber]

Can anyone with more experience speak to how necessary the thermostatic tee is in the US climate (Ohio)? I'd prefer to delete it and save the trouble if it's not necessary.

The tee will return some fuel to the filter to warm it slightly & keep fuel from jelling there.
I always wondered if after the fuel temp gets high enough it returns more to the tank to heat the fuel inside the pickup in the tank. (not heat the entire tank)

When I had a VW pickup (1.6 diesel) I put a GM diesel filter in place of the VW filter.
Price was much cheaper, worked fine for 2 or so winters.
One colder morning I went about 10 miles & coasted to the side of the road.
Tow'd the car home, found no fuel in the clear line.
Put another GM filter in, primed & added a lot more anti gel additive in.
Got through the winter using 3 times the additive.
Replaced the correct filter in the spring.

Rich W.