How Many Miles before injectors need replacing?

[Bugsy_malone 666]

I'm guessing this is a how long is a piece of string question, but I wondered if there is a service interval on injectors?

Its just tail end of last year I started using veg oil which was fine, but slightly before I started using it I was noticing the van wasnt exactly easy to start. Even with a twin tank system I found using veg oil (heated and everything, I built a proper setup) problems became worse when it came to starting from cold.

So the other week I started my van up, I now have the cold start fitted (and its spring loaded so you have to hold it out) and after 30 seconds I released it basically the engine stumbled and stopped. It didnt used to be like this, was fairly smokey(like bluey/grey I'm cold type smoke), but I tried again holding it out for longer and then holding the throttle to warm it up a little. This may sound 'ok' if the temperatures were below freezing but it was about 8c outside and I havent had this before when its this 'warm'. But back in november is was more like 15c and it was still acting like this, I even altered the timing a nats to help but the only way it runs anygood if not upto temperature is with the cold start on.

Got me thinking the other day though, the engine has 155k on it since 1987, maybe the injectors need replacing? We have an old 60s ford tractor which is similar (really smokey on start up, clears within a minute or 2 of being warmed up or on throttle but has a constant haze)

The crazy thing is, after letting it warm right up my van was fine and ran 'clear' pretty much.

[wolf_walker]

Might be an obvious suggestion, but check the glowplugs first. 

Otherwise I'd run a heavy dose of fuel system cleaner through it, like diesel purge from LM out of a dedicated container. 

[Bugsy_malone 666]

 yep first thought was glow plugs, I had replaced them 2 years ago, but then replaced them in november to find they are fine.

I been running fuel system cleaner through it, but it hasnt made much difference. Basically at the begining of November the tank was pretty much empty, and I filled up a a fuel station with fresh fuel, also filling my WVO tank with filtered good quality used oil (from where I work, it doesnt get used much) and its fine once its warm, but fuel economy seems crap and its fairly smokey on start up. Our tractor is really smokey on startup till it gets warm and so was a stationery diesel engine I used to have which was injector dribble, which is hy I wondered about buying a set for my vans engine (which aint a cheap job!).

[wolf_walker]

Bad spray pattern can sure do it, and a lot worse.  Any air in the pump feed line?
The diesel-purge procedure with that stuff from LubraMoly will clean up stuff that running
regular fuel system cleaner will not in my experience. 

[8v-of-fury]

What engine is in the van?

[fatmobile]

Clear fuel lines?

[92EcoDiesel Jetta]

If you run on veg, it's a good idea to take the injectors out every 10K miles or so and clean the build up on the nozzle/pintle with a soft brass wire brush/ solvent and then pop test for spray pattern. Running veg will cause more build up on the nozzle  than diesel and this buildup will affect the spray pattern and how the engine runs.

[R.O.R-2.0]

If you run on veg, it's a good idea to take the injectors out every 10K miles or so and clean the build up on the nozzle/pintle with a soft brass wire brush/ solvent and then pop test for spray pattern. Running veg will cause more build up on the nozzle  than diesel and this buildup will affect the spray pattern and how the engine runs.

idk if diesel purge, or any fuel system cleaner will touch veg deposits, will they?

[RustyCaddy]

Seafoam works for removing the veg oil varnish after brass wire brushing disassembled injectors in regular diesel.  You might try switching to Bosio GTD, Monark or Elsbett nozzles.

[92EcoDiesel Jetta]

If you run on veg, it's a good idea to take the injectors out every 10K miles or so and clean the build up on the nozzle/pintle with a soft brass wire brush/ solvent and then pop test for spray pattern. Running veg will cause more build up on the nozzle  than diesel and this buildup will affect the spray pattern and how the engine runs.

idk if diesel purge, or any fuel system cleaner will touch veg deposits, will they?

Diesel Purge, Seafoam or any of the injector cleaners is only mildly effective against veg deposits. A good quality carburettor cleaner is much more effective on veg deposits but you must soak the part in it for a few hours.

[fatmobile]

 Lye will easily remove vegetable oil that has hardened on a surface.
 Might be off topic:
 because lye could eat into the metal too
 and might not remove heat hardened stuff from injectors..

[Bugsy_malone 666]

Well I have used veg oil for a total of 400-500 miles and thats it so I wouldnt have thought its caused a massive problem quickly.

I went to start it today and its not been run for about 3-4 weeks and jeez did it start like a bag of ***! Pulled the cold start out (and held it because of how mines sprung loaded) cycled the glowplugs (new) spun it over and it took a fair bit to get started where it was smokey and generally aweful!

So I ran it tried clearing it with the throttle and it was like a bonfire, I let the cold start go and it ran crap, its not been this bad for a long while.

So after 10 minutes of running it, it sounded pretty clattery and bad (like something serious might be up) pulled the cold start out and it ran fine. with a slight haze.

It didnt seem to really change the way it ran even when on Veg oil! but either fuel it was missing a little bit.

So I thought well maybe the injectors are kapusk and I need to replace them all, which for a set isnt exactly cheap, I thought what about slipping in a set of non turbo injectors for the time being? someone said they fire at a different pressure? how much by and whats the difference? I thought maybe for testing how it runs it would be a good way to test the injectors (although if they crack off at a lower pressure and theres a problem with the pump I wouldnt know) as the injectors from my old 1.6N/A I dont think ever had a problem, it ran fine with no/little smoke.

I also wondered how much difference pump timing would make to dodgy injectors? and when advancing the pump timing (like the cold stard does) you turn the pump slightly towards the engind?

[ORCoaster]

Interesting behavior.  Timing really off on it I say. 

To mimic cold start lever:  IP gets pushed towards engine, push to advance pull to retard.  Just remember to go easy, like pencil lead width of a push.  Mark the position of the pump in relationship to the bracket line. 

Slight haze with lever out may be better running but still not enough timing bump.

[Bugsy_malone 666]

Its the missing and stumbling I dont get which makes me question is the IP a bit worn causing the injectors to not pop everytime.

So far previously I moved the fuel pump towards the engine by a pencil width, if that but it didnt make a noticable improvement.

The bit I dont get is why am I adjusting the pump at all at this stage as when I got the engine I did the cambelt and it ran fine from day one, but overtime its gotten worse for no real reason, its not like it does all that many miles, its just gone down hill massively over time (4 years but maybe only 4k miles) now I wonder if maybe moisture has erroded the injectors or something has just stuck up, I even wondered if sticking hydraulic tappets could be causing injector smokey problems?

Do you think there would be any problem with sticking N/A injectors in a TD?

[ORCoaster]

Not sure about the injector swap as I don't have that knowledge base.  Someone else chime in here eh? 

It almost sounds like worn IP or possibly dirty or gummed up vane pump.  I have a gauge on my IP so I absolutely know what the pressure is at idle, just off idle and full on to the floor blow it out the tail pipe pressure I have.  Your symptoms remind me of a pump I had to rebuild and it had that intermittent performance.  I found one of the four vanes to have a burr on it that would prevent it from pushing out to the outside of the pump housing.  In addition a second vane was binding on buildup varnish like junk.  Once I tore it apart and cleaned it up it was totally useless, I mean it ran great. 

So have you had the pump apart at all?  How old of a pump are we talking about?

It is that sudden failure thing, that makes me think all is not well inside.