Idle issues

[gtiaddict]

Hey everyone just swapped my 83 rabbit convertible to diesel, its havin g idle problems, its getting fuel to all 4 injectors there is no air in the lines, and it will start run for a few seconds then die, glow plugs are only rigged up wiring wise for testing, and the advance cable is not hooked up. Should i try adjusting the fuel screw?


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[theman53]

I would try hooking up everything correctly first. Then maybe give it some fuel by holding the arm off the idle position to see if it runs.

[ORCoaster]

What I have always found to work is that you put your foot 1/3 or 1/2 way down on the Accelerator pedal or pull that throttle lever some on the pump if outside prior to hitting the key.  That initial rev up of the engine sets up the Alternator charge and just seems to flush out weirdness in the IP.  Air, gov limiter or what ever under the top of the IP.  Just hitting the key and letting it putt putt is fine but you have to get it warm or after the rev thing settles down. 

Odd I know but it seems to always work.  At least on my engine and now a couple of different IP on it.   

[gtiaddict]

Alright ive tried starting it, ive heard it sputter and die but it wont run with full throttle r anything, there is not air in my fuel line, im pretty sure im getting heat to the 4 new glowplugs, it turns over hard but i dont hear it fire...


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[gtiaddict]

I have found the fuel im only getting fuel to the second right hand side i jector, i cracked my lines at the injector tips and im not getting fuel to the rest, whats going on?


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[ORCoaster]

PULL THE CHECK Ahem, DELIVERY VALVES at the back of the pump and be sure that all is clear and free in there.  There is a copper washer at the base of them next to the IP head, inside is a piece of metal that looks like the end of some sort of torx bit, a spring and then a spacer.  You should be able to verify airflow in and out of these when off the engine. 

Because we don't know if this swap was made with a running engine I will assume it sat for a while and that the internal pump passages are plugged or the check valves are.  Cleaning the check delivery valves does not require the pump to be pulled apart.  So it is the go to fix for now.  If that fails then soak in diesel Purge for a couple of days?

Anyone ever try baking an IP in the oven at 180-200 degrees to see if that helps break off the sludge layers that we find on these pumps after they sit for years and dry out?

Just a thought, and a smelly kitchen idea. 

[gtiaddict]

Where is the check valve? And the engine sat for 5 years he said, its a 1.6 n/a he said it ran when pulled, would an electric pump inline fix the issue? I also have no return line hooked up fight now until i get it running


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[gtiaddict]

Fuel is knly dripping every few seconds out of the injector lines if at all


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[gtiaddict]

Checked the pump by removing the return banjo and it was empty, i will it up and bled the lines, it will start and maybe idle for a second or two then die, ALOT of white smoke is coming out.


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[ORCoaster]

There are 4 check delivery valves on the back of the IP head.  That is where the delivery lines to the injectors screw to.  See half way down the page on this thread.  #54 is the one shown,  exploded view gives components.  http://www.vwdiesel.net/forum/index.php/topic,30340.0.html

You have no line going back to the tank?  Did I read that right?  Where is all the fuel going then?  Or is that the problem?  No fuel out that top banjo would mean stuck vanes in the primary pump.  A common trouble for pumps that sit for much time at all.   I just had to fix this on a pump I swapped into my 81 Rabbit.  Had to tear it completely down to get to that part.  It is way deep in there. 

Not an easy fix by any means. 

[92EcoDiesel Jetta]

PULL THE CHECK VALVES at the back of the pump and be sure that all is clear and free in there.  There is a copper washer at the base of them next to the IP head, inside is a piece of metal that looks like the end of some sort of torx bit, a spring and then a spacer. ........

Those things are check valves but more commonly called delivery valves on IP's.

[gtiaddict]

Yes found the problem...my return line wasnt hooked up so it wS sucking in air, i fixed it and it fired and idled great, just a slight back fire every blue moon due yo knly running header...but still alot of white smoke, and when i pull the throttle nothing if anything at all happens.


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[vanbcguy]

It can take a WHILE to get all the air out of the pump.  The throttle won't respond much if the pump is still full of air.

'Backfiring' is kind of odd, describe what you mean? 

[ORCoaster]

This is the main reason we all advocate that you put clear line on both sides of the IP.  So you can see if air it going in or coming out of the pump.  Very necessary addition in order to get a quick read on what might be happening with internal functions.  Liquids are great for maintaining and building pressure but add some air and all the dynamics go out the window.  That is why we see smoke out the back of the car when air in in the pump.  Things just aren't working as intended.

Keep the engine running a bit at idle and try revving it every once in a while.  If you still don't get a positive response then I would venture a guess at the vanes being stuck.  Or the internal pressure set too low with the regulator plug at the front of the engine.  I was running pretty good with only 5 lbs of internal pressure but it runs soo much better after tapping that peg down a bit and now running with the 43 lbs at 1000 RPMs.  Need a gauge on the pump for that.  But surrogate is simply measuring flow out of the pump over 90 seconds of time.  Should get a liter of liquid.  I think those numbers are correct. 


Edits on previous messages where Delivery Valves were described as Check Valves as per 92EcoDiesel Jetta mention.  Keeping us withing spec language, good deal. 
The only other fix would be to realign the throttle lever as described in numerous threads on this place.  The shaft moves counterclockwise to the reference of the lever.  One spline at a time to get best throttle response.