IP reseal sucessfull, pump still dry overnight!

dkmc · Post by **dkmc** » Sun Oct 21, 2007 11:44 am

OK guys, lots of work in the shop, so JUST yesterday I got the clear blue fuel lines on (motorcycle shop) the Jetta.
After I drove it around a few miles both the fuel line and return line are completely full and NO bubbles.

This morning, NO start again!
It acts like the glow plugs are bad.....like 3 are bad.
But they are not, I checked them when I had the pump off.
They are not new, but all function ok.

This is really getting frustrating. For the last 2 weeks, with the aux. elec. pump hooked up, the car starts cold in the morning.
I have to let the pump run a bit, so 2 glow cycles worth before there "seems" to be enough fuel getting where ever it gets, then it starts in a few turns.

Today, it took "minutes" of cranking, complete with smoke out the exh. pipe like the glow plugs are cold. You know the routine..... they run on the starter, then eventually decide to wean off the starter and run on their own.....jeesh.

Sounds like/ seems like it has enough fuel, and it starts if the aux pump is in place......

NO leaks of fuel or oil at this point.....the motor is leak free.

This hard start condition came on in a few days.
One day it was starting cold just fine, then a bit of trouble one day, none the next, etc.
My next guess is FOUR new glow plugs, but that's a lot of money to guess with.....

I am at a complete loss here.......

ANY ideas.....???????

82vdub · Post by **82vdub** » Sun Oct 21, 2007 11:54 am

Sounds like the car starts just fine with the aux pump, but doesn't when the aux pump is not installed. Is there still fuel in the clear line going to the IP when it won't start?

Since you have to run the aux pump for a while before fuel gets to the motor, my initial thought on this is that you've got a huge vacuum system in the tank somewhere and over night it's pulling your fuel back into the tank. If not, the aux pump would fire the engine right up, and probably the same without the aux pump hooked up.

As a test, run the car for a while, and remove the fuel filler cap and let the car sit overnight and test starting without the aux pump and then try it again with the aux pump operating and see if there is any difference.

dkmc · Post by **dkmc** » Sun Oct 21, 2007 1:20 pm

Is there still fuel in the clear line going to the IP when it won't start?

Yes ! Totally full of fuel no bubbles......
Weird huh?

my initial thought on this is that you've got a huge vacuum system in the tank somewhere and over night it's pulling your fuel back into the tank.

Can't be.....this morning.....line was full of fuel........so is the return line.

An aux fuel pump does not fix bad glow plugs so this is why I'm totally confused here...

Although.....in cranking, it did get to the point of smoking while cranking, like it's got fuel but no glow plugs.

And it mostly came on 'overnight' about a month ago.

The weather is unusually warm here yet.....but soon I will need this thing to start right away in winter.......hum.......

As a test, run the car for a while, and remove the fuel filler cap and let the car sit overnight

I will do that tonight........

dlk

libbybapa · Post by **libbybapa** » Sun Oct 21, 2007 2:24 pm

How did you check the glow plugs?

Andrew

dkmc · Post by **dkmc** » Sun Oct 21, 2007 2:33 pm

I took each GP out and hooked it to the battery for 4-5 seconds.....till they
started to get red....
There is power at the GP cable.....

I'm not saying they are great, but the all did get red.

Still if they're not the best, the Aux. fuel pump isn't helping them....I'm pretty sure of -that- anyway!

Things don't add up here........

I will also crack an injector line fitting tomorrow morning to see if fuel squirts as soon as I begin cranking without the Aux pump in circuit.....

tawney · Post by **tawney** » Sun Oct 21, 2007 6:15 pm

How about puting a voltmeter on the glow plug circuit and watching it when you go to start the engine just to make sure that the good plugs are getting the juice they need?

Steve

dkmc · Post by **dkmc** » Sun Oct 21, 2007 11:01 pm

Steve,
You have stated what I thought of earlier when I was out for a drive enjoying the great fall weather here, and rethinking the possible causes to this mystery.
I -said- the GP cable has voltage......BUT I have failed to check it when this specific starting problem occurs.
I assumed it's got voltage all the time. BAD troubleshooting procedure!

It's very possible this is an intermittent glow problem, (relay is prime suspect). This would not be the first time this has happened, the relays do have a habit of failing intermittently. Or a bad connection, or a oxidized relay socket....etc.

This one I will check tomorrow when cold !
Now I'm hoping that's IT.

thanks
dk

dkmc · Post by **dkmc** » Mon Oct 22, 2007 11:39 am

This morning, I connected a MM to the GP lead on the engine and positioned it so I could see it from inside the car. Turned the key and it showed 10+ Volts..... It cranked about 2 turns and fired up.

I need a GP indicator light inside the car someplace......has that topic been discussed on here someplace?

Glad I found the problem with help from those on this forum!

dk

tawney · Post by **tawney** » Mon Oct 22, 2007 3:43 pm

I think someone on the forum has installed a voltmeter gauge that is wired to the GP system so that when it is on, he can see the voltage; seems like a light would be simpler and just as effective.

Steve

82vdub · Post by **82vdub** » Mon Oct 22, 2007 4:05 pm

Someone else (I think) wired a little LED light to the glow plug bar and attached that LED light to their wiper arms. Took only a few minutes to install.

Post by **Fatmobile** » Tue Oct 23, 2007 12:33 am

I think that was vwcaddy who connected a light to some windshield washer LEDs.
Great idea, you don't even have to run the wire through the firewall and to the instrument cluster like I did.

Post by **Fatmobile** » Tue Oct 23, 2007 12:34 am

10 volts doesn't sound too bad.
What was the voltage drop from the battery to the glow plugs?
How much power did you lose due to the connections and relay?

CoolAirVw · Post by **CoolAirVw** » Tue Oct 23, 2007 8:30 am

dkmc wrote:This morning, I connected a MM to the GP lead on the engine and positioned it so I could see it from inside the car. Turned the key and it showed 10+ Volts..... It cranked about 2 turns and fired up.

10 volts may not be enough in my opinion. Yes, I know it started in 2 turns.

I read a trade journal once that explained that a properly charged battery has 12.6V and a battery with 12.1 is 75% discharged. It didn't come with an explanation or I would share it but it came from a reliable source. (Auto Trans Rebuiders Association)

All I can say for now is at 10V there is less amps flowing through glows (and therefore less heat) than there would be at 12.6V. Not to mention voltage to turn the starter. Little bit colder day and your battery puts out less CCA, maybe car starts maybe not.

I'm not saying this is your problem. Maybe all I'm saying is you should put the exact voltage you read and not 10+.

Just because its free you should stop by a Freindly Local Autopart Store that tests batteries for free and see what their tester says about your battery. Just make sure that the battery terminals are clean because the tester we use at work calls batteries bad if there is a bad connection. Dont just clean where the cable meets the post but clean the outside where the testers clamps hook.

Fatmobile wrote:What was the voltage drop from the battery to the glow plugs?
How much power did you lose due to the connections and relay?

Good tests there. If you have 12.6V at battery and glows have 10V then you've allready found the problem. This would mean high resistance somewhere, probably the relay.

3Bunnys · Post by **3Bunnys** » Tue Oct 23, 2007 9:11 am

Well while we're running tests...here's another one....
For cold start tomorrow jumper battery directly to glow plugs with piece of wire and monitor voltage....count to 15 or whatever then hop in car and hit the starter......
One of several suspects for GP's not getting sufficient current is that aluminum fuse on firewall.... Take a "Close" LQQk at it.... maybe a hairline crack, some erosion/corrosion maybe...... quick test is just to bypass it for a day or three,,, hook both wires under one screw.... see how things go...
the blond says good luck...

Richard

hagar · Post by **hagar** » Tue Oct 23, 2007 9:50 am

am at a complete loss here....... -------hagar say You are EH ? ---NO you are NOT ---you found this forum --EH ? you cant loose.

That problem is OLD hat to us elders. ---that is like mumps or chicken pox or Nail-biting --need I go on ?

hagar will NEVER tell you what to do --OK ? ---BUT I will tell you what I would do.

first I remove electric fuel pump , and install a squeeze bulb instead.

NO leaks EH ? then I know AIR is getting in to the fuel system , otherwise fuel can NOT return to tank when car is parked ---- then I pull on the 9 Chinese Fingerseals on drain lines --- to make sure they SEAL.-----YES PULL.

Then I park nose downhill overnight ----then nose uphill. --and observe. -------then I make sure correct fuel-cap is used. ----A cap for a steel tank --may collapse a PLASTIC tank --that is why the cap must work.

That inf. will get you started --EH ?----got me started so why not you ?.

hagar.

Former VWDieselParts.com Forum

IP reseal sucessfull, pump still dry overnight!

Probllems EH ?