1.6 td hard starting - Solved

[scrounger]

In the last month my Jetta has been getting harder to start. It used to light up with the first twist of the key.  It bucks and smokes after 15 seconds of cranking.

It is summer here and 75 degrees in the morning and over 90 mid day.

At the last fill I put in 20% bio diesel from a known good source.

Have read that most of the time it is the glow plugs. I replaced them about 18 months ago.

Have also heard that sometimes biodiesel is more of a solvent and can stir up the pot causing filters to sludge up. I assume that there is a booster pump in the tank to get the fuel to the main filter.

It runs normal with normal power once it has been going 10 seconds.

My plan is to see if the glow plugs feel warm after cycling them. The orange LED comes on just like normal. I may try plugging in the car as a test. I have a spare fuel filter and will probably install it as well.

I doubt if there is anything really that wrong as the engine runs perfectly normal.

Comments appreciated
thanks
Scrounger

[CRSMP5]

1st make sure power to glow plugs

2nd change filter

if its still a issue after that.. then things like ater seperator, screen in tank..

[R.O.R-2.0]

sounds like the bio-diesel may have softened up a feed line just enough to make it leak some air, and lose prime..

[745 turbogreasel]

I look for air in a line first, it's quick, cheap, and causes half the problems in diesels.

[scrounger]

Is there a booster pump or filter in the tank? Or just the filter on the fender well? Sorry I am ignorant.

[libbydiesel]

Clear line before and after pump?  Any bubbles?

[CrazyAndy]

No booster pump in these older diesels.  Yes, the fule filter is on the fender well.  Do you have a clear pump feed line?  If so can you see bubbles?  How long ago did you start running bio mix, because afer a while bio will cause older seals and hoses to get soft and leak due to the decreased abount of lubricant in bio.

Like 745 said, check for air, if none then change filter in front, then if still problematic then look at in-tank screen sock.

[scrounger]

As a couple have asked about clear lines. I just bought some clear lines.

Saw a couple of videos showing what to look at with changing one. They were for a TDI which mine isn't. Is the IDI  similar?

This was the first tank of the biodiesel.

The problem may have started previously but it has definitely gotten worse since the last fill.

It is taking 3-4 seconds to start even with the engine warm now. I recall that it was nearly instant 3 months ago.

[theman53]

I would suspect the rubber lines from the pump out and in between the injectors. They usually leak from just diesel in less than 2 years. Bio through them usually ruins them in short order.

All other suggestions above are spot on too, I am just giving another option.

[Dakotakid]

Just because the glow plug light comes on does not mean the glow plugs are getting juice.
Hint:  there is something between the relay and the plugs.

Come on....ya gotta make these new guys put a LITTLE effort into things! Sheeeeeesh!

[scrounger]

Thanks for the help all. I got a chance to open the hood and found a cracked rubber fuel line on top of the fuel filter.

Took it off and sure enough the tubing was dry inside and the fuel filter was down some. I had some clear tubing and put it on. I topped it up with a syringe and after running it stayed full.

Got lucky.

[scrounger]

Here is what I found.