Author Topic: Rebuilt injectors not firing  (Read 8722 times)

Reply #15May 07, 2014, 11:30:58 am

Mark(The Miser)UK

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Re: Rebuilt injectors not firing
« Reply #15 on: May 07, 2014, 11:30:58 am »
Just wipe the injector faces.
If the valve sealed then injector may be perfect inside.

An injector that has seen a lot of wear will have a toroid or doughnut groove.
This does not affect injector performance
Mark-The-Miser-UK

"There's nothing like driving past a bonfire and then realising; its my car on fire!"

I'm not here to help... I'm here to Pro-Volke"

Be like meeee: drive a Quantum TD
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Reply #16May 07, 2014, 04:21:46 pm

sgnimj96

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Re: Rebuilt injectors not firing
« Reply #16 on: May 07, 2014, 04:21:46 pm »
       For a different test I pieced together and installed 4 used injector and nozzles,  calibrated to around 1800 psi,  with fair spray patterns.     
   I re-used the heat shields (Thanks Mark) , got a better battery charger for faster cranking,   and after getting plenty of fuel out the hard lines.....
  Nothing    , 
  Checked the timing again then retarded to back to .88 mm   ,  with or without the coldstart....  Nothing
 All I ever see is a little misty smoke inside the tailpipe if I use a flashlight.     
     Too weird
So I guess if the inverted injector test doesn't  fire the injectors, then I need a new IP ?   
  That thing ran pretty good before I took the injectors out  ???

   
81 Scirocco 1.6D (conversion)    86 Gofl 1.6D      2003 Golf Tdi   1985 300TD

Reply #17May 07, 2014, 05:06:48 pm

theman53

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Re: Rebuilt injectors not firing
« Reply #17 on: May 07, 2014, 05:06:48 pm »
Maybe something needs help? Try pull starting it once it is back together. Every time I take the lines off there is enough air to make it hard to start, but not impossible. Maybe it is compression issue, but why it would have surface right now is kind of a mystery.

Reply #18May 07, 2014, 05:42:55 pm

burn_your_money

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Re: Rebuilt injectors not firing
« Reply #18 on: May 07, 2014, 05:42:55 pm »
Is the 12mm bolt that is removed to check pump timing tight?

If it is, I agree with pull starting.
Tyler

Reply #19May 07, 2014, 06:06:38 pm

air-cooled or diesel

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Re: Rebuilt injectors not firing
« Reply #19 on: May 07, 2014, 06:06:38 pm »
'only' a few things need to come together to get these engines running; air going into cylinders +cam&timing go with this, &no restrictions. compression, fuel delivery, +pump timing goes with this.
the only other things you need are voltage to solenoid, cranking speed, and cold start(gps).
so these are your points to check. unless its found you have an exhaust restriction,

Reply #20May 07, 2014, 06:43:09 pm

Mark(The Miser)UK

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Re: Rebuilt injectors not firing
« Reply #20 on: May 07, 2014, 06:43:09 pm »
      For a different test I pieced together and installed 4 used injector and nozzles,  calibrated to around 1800 psi,  with fair spray patterns.    
   I re-used the heat shields (Thanks Mark) , got a better battery charger for faster cranking,   and after getting plenty of fuel out the hard lines.....
  Nothing    ,  
  Checked the timing again then retarded to back to .88 mm   ,  with or without the coldstart....  Nothing
 All I ever see is a little misty smoke inside the tailpipe if I use a flashlight.    
     Too weird
So I guess if the inverted injector test doesn't  fire the injectors, then I need a new IP ?  
  That thing ran pretty good before I took the injectors out  ???

    
So as  I understand it, because you doubt the injectors are spraying inside the engine, you took some older ones, and inserted those and cranked with no results. No firing and no smoke.

This could be construed to mean that the pump is bad, or the grossly erroneous timing is still grossly erroneous. The chances of no injectors working is 1 in 256. [2^8].

If you did the visual test, you would know in seconds if your injectors are injecting and if the spray pattern is within the very wide range of adequate functioning. If they were then you could move on to timing the pump...

If they were not spraying at all then, the pump is at fault. [Or it's fuel supply]

Do the test, and get the results!
« Last Edit: May 07, 2014, 06:46:31 pm by Mark(The Miser)UK »
Mark-The-Miser-UK

"There's nothing like driving past a bonfire and then realising; its my car on fire!"

I'm not here to help... I'm here to Pro-Volke"

Be like meeee: drive a Quantum TD
 ...The best work-horse after the cart...

Reply #21May 07, 2014, 06:53:04 pm

air-cooled or diesel

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Re: Rebuilt injectors not firing
« Reply #21 on: May 07, 2014, 06:53:04 pm »
I don't have any problems with quantam mans test, just don't get near the line of spray,, it ll tell you a lot right there,,just do it carefully and don't do something stupid like have a problem with the inj lines.

Reply #22May 07, 2014, 07:09:30 pm

vanbcguy

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Re:
« Reply #22 on: May 07, 2014, 07:09:30 pm »
Throw a clear plastic bag with an elastic over the injectors if you are worried.

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Bryn

1994 Jetta - AHU M-TDI - Jezebel Jetta
2004 Jetta Wagon - 1.8T - Blitzen

Reply #23May 07, 2014, 07:43:52 pm

Mark(The Miser)UK

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Re:
« Reply #23 on: May 07, 2014, 07:43:52 pm »
Throw a clear plastic bag with an elastic over the injectors if you are worried.

Sent from my HTC One XL using Tapatalk

Good idea,which also demonstrates the momentum of the jet
 
Mark-The-Miser-UK

"There's nothing like driving past a bonfire and then realising; its my car on fire!"

I'm not here to help... I'm here to Pro-Volke"

Be like meeee: drive a Quantum TD
 ...The best work-horse after the cart...

Reply #24May 07, 2014, 09:48:59 pm

sgnimj96

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Re: Rebuilt injectors not firing
« Reply #24 on: May 07, 2014, 09:48:59 pm »
I can't seem to get the lines in upside down.    Took the alternator out,  still just doesn't want to work.
   
Still can't image how the ip could be bad.       It ran with a serious restriction when i got it,  constant bubbles in the system,   leaks,   crud inside.      Resealed it due to a rpm hang (that's when I found the crud).     Ran better than ever,   started easy, ... but the injectors were worn out:   clatter when cold,   rough low idle;   so I made a pop tester,  pulled the injectors;  and sure enough the pintles were all carved out and the pop pressures were low and uneven.

I have a cheap electric fuel pump on the way from ebay.   Found out my other one was failed just as I started with the install.      I don't think it was restricting the flow   but I bypassed it after a few failed attemps to start.
81 Scirocco 1.6D (conversion)    86 Gofl 1.6D      2003 Golf Tdi   1985 300TD

Reply #25May 08, 2014, 01:44:06 am

Toby

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Re: Rebuilt injectors not firing
« Reply #25 on: May 08, 2014, 01:44:06 am »
You most likely had a GP problem to start with, but since you have been playing with so many things, you now may have multiple issues. Tow start the thing. See if it restarts hot.

If you have the injectors out, cycle the glow plugs and look for little curls of smoke and glowing tips. Unless you can see them heat you do not know they are good. I have seen a number that have the right resistance and no gross deformities but only get luke warm.

Pull start it and then you will know. FWIW you can get an IDI to start with 200 psi compression and no GPs if you drag it far enough. I will drag start a diesel long before I will start taking things apart. Some times you can wash all the lube oil off the cylinder walls, if you crank one too long w/o starting. Once you wash down the walls the ring drag is quite high yet you have no compression to speak of. Drag starting these is often your only option short of waiting a few days for the diesel to run by the rings and then remove the GPs or injectors and add a touch of oil to each hole. OR you could just pull start it.

Reply #26May 08, 2014, 04:19:51 am

sgnimj96

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Re: Rebuilt injectors not firing
« Reply #26 on: May 08, 2014, 04:19:51 am »
        Getting a tow would be difficult.
      The glow plugs do work,    got an active visual with the injectors out.
    I'll get the compression tester from HF
81 Scirocco 1.6D (conversion)    86 Gofl 1.6D      2003 Golf Tdi   1985 300TD

Reply #27May 08, 2014, 04:42:10 am

air-cooled or diesel

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Re: Rebuilt injectors not firing
« Reply #27 on: May 08, 2014, 04:42:10 am »
rotating the inj lines assembly 180degrees should do it, alt bracket is on the other side; this is what im taking about, don't end up having problems. I haven't done this, but it seems rather straight forward, there is a pic;,somewhere. if you have lines loose and over pump and injectors, visualize turning assy over the top, upside down, 180 degree turn, ends up pointing at up your face as your looking from top. I don't think theres much there to obstruct it.

Reply #28May 08, 2014, 09:12:40 am

sgnimj96

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Re: Rebuilt injectors not firing
« Reply #28 on: May 08, 2014, 09:12:40 am »
       Compression tests good,  all are ~500 psi , according to the HF gauge.   Got my starting system well grounded and charged,  so it cranks over fast.

    Heat shields had the same stuff on em,   put a lighter on em and no sizzle,  smelled dieselly.         Injectors look wet at the nozzles.      

            The light smokey mist that I could see in the tail pipe (only with a flashlight) had a faint odd smell,              I'm thinking now that was unburnt fuel,  or maybe just condensation from the air
  
    Could the timing be so far off as to never ignite the fuel during compression?      
« Last Edit: May 08, 2014, 11:34:44 am by sgnimj96 »
81 Scirocco 1.6D (conversion)    86 Gofl 1.6D      2003 Golf Tdi   1985 300TD

Reply #29May 08, 2014, 11:40:23 am

Toby

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Re: Rebuilt injectors not firing
« Reply #29 on: May 08, 2014, 11:40:23 am »
Difficult or not you need to tow it.