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Engine Specific Info and Questions => IDI Engine => Topic started by: James8485 on March 07, 2008, 07:55:55 am
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i am overhauling my motor and the head is off and the guys who rebuilding it says that injecter almost never go bad....he wouldnt condem an injecter. he also said that if they dont come out easy then you could risk cracking the head where they screw into.....
any thoughts as my heasd is off and they look pretty old but my injection pump is also getting rebuilt so dont need one to be bad! anyway to test in the head> or tips on getting them out
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Injector nozzles do have a design lifespan and should be replaced as part of normal maintenance. I think the interval on replacement is something like every 60k miles.
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removing stuck injectors can break the head.
I think using an impact gun is the best way because all the force is exerted in a twisting motion.
Using a breaker bar some of the force is exerted into the head. Libbybapa says... "always push the breaker bar torward the head", because if you push away from the head there is no support and the front part of the head might crack out away from the head.
IF you guy is surfacing your head you really need to remove the injectors.
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Of course they can go bad, nothing lasts forever. In fact, I believe that it is recommended to replace the nozzles every 40-60k miles. They can get worn, they can get dirty or coked up. If the spray pattern gets bad enough, it can actually ruin your engine by melting parts from a poorly atomized stream causing an excessively rich burn and high temps. At the very least, they will start to affect power and mileage.. You do have to be careful removing them. It is best to do with the engine warm. Either way, push your wrench/socket towards the head, don't pull it away from it. Loosen a partial turn, tighten just a little and repeat, kind of like cutting threads. Penetrating oil will help as well.
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I heard that using a t-bar works good 'cause, like the impact wrench there is no side load.
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Impact gun is not good!It will crack the boss if their is "any" corrosion.
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I've used both impact and breaker bars and I prefer the breaker bar simply because you can feel what is going on. Moving it back and forth many times before trying to remove the injector helps free it a lot. Penetrating lube is highly recommended. If the head is on a bench an impact would be a lot easier.
It sounds like this guy doesn't know how to remove injectors so I wouldn't ask him to.
At the very least if you are getting the pump rebuilt you should have the injectors tested.
As mentioned they are only good for about 60k miles (100k kms)
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Sorry,just telling my experience :? If the injectors havent been changed in awhile ,and no no- seize is on the thread then i think its best to soak them for a couple days prior :D
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what happens after 100,000 k ? .....
seriously ,
i've seen many engines with up to 5 times that many miles , with nothing more than oil changes , and the odd timing belt . and they run very well
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The breaking pressure also wears and the injectors open earlier. Also, they usually all don't wear uniformly so you'll be stressing out the engine by unbalanced loads in the cylinders
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any one know the size of socket needed for the injecters?
at one shop here they had an injecter stick open while under load...it was like a blow torch...washed out the side of the cylnder and piston...that was in a international tow truck tho lol
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i am overhauling my motor and the head is off and the guys who rebuilding it says that injecter almost never go bad....he wouldnt condem an injecter. he also said that if they dont come out easy then you could risk cracking the head where they screw into.....
any thoughts as my heasd is off and they look pretty old but my injection pump is also getting rebuilt so dont need one to be bad! anyway to test in the head> or tips on getting them out
To remove clamp the head on something secure, and maybe have someone hold it. Depending how corroded they seem, they may need pre-soaking.
Use a 'T' bar +1ft extension and swivel joint to prevent any leverage. If still tight after moving a little, then act like you are cutting a thread.Add more lube too. Use a pneumatic nut remover [wrench] with care...
The injectors are 27mm. However some sockets are a little tight inside and can damage the two barbs.
I overcame this by accident with the purchase of a 28mm socket, and I filled the gap up with an insert of baked bean tin 8)
Injectors do wear, however, an old nozzle may have started from a better position of quality than a new one. Break pressures do lower over time as they settle in.
However, good zozzles may over time become great nozzles which only slowly taper off in quality.
Once you have you injectors out , if they can be checked then they may still be good, or if spray pattern skewed, merely dirty.
You are looking for similarity of spray pattern, non dribbling for say 30 seconds pressure test, and similar break pressure within 5bar, or nicer within 2bar Absolutely identical spray performance is not essential, as with the IDI swirl chamber the spray droplets are sheared and mixed by the swirling....
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any one know the size of socket needed for the injecters?
I bought a provalue 1 1/16" socket that works good, make sure it's big enough inside to clear the return barbs.
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thanks for that.....i have a leaking one on a engine i just bought....see if it just needs to be tightened a bit...if not il pull the ones from my old engine....those where fairly new...so if they are hard as hell to turn you just work them in and out? is that carbon in the threads?
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i use an impact i think its safer than a breaker bar because of how u apply torque, but i'm no engineer or anything. i always put it on the lowest setting too.
i have always heard to change them every 100,000 miles
bad injectors can leak, or put too much fuel in, causing over heating in that cylinder which can eat away at the pistons and head and also crack the head, warp the valves. they can really do a lot of damage and are nothing to over look
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thanks for that.....i have a leaking one on a engine i just bought....see if it just needs to be tightened a bit...if not il pull the ones from my old engine....those where fairly new...so if they are hard as hell to turn you just work them in and out? is that carbon in the threads?
You need to be sure exactly wheere the injector is leaking before you try and tighten it further.
Wipe with tissue and see if leak is from old leakofff pipe, fuel line nut , injector body at split, or coming up the threads, or even merely old diesel boiling off the threads from an earlier leak.
Tightening the wrong part is, naturally, unproductive, but will also cause other issues if you are unlucky.
Threads that truely are carboned up need to be treated with care due to the soft nature of the head threads. That is what the air wrench struggles with. If diesel is bubbling up then it will not be hard to undo.
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well i have the injecters out....the one that was leaking was leaking past the treads....i ran the car for a hour to see if it would clear up after washing the area....i pit my IP in a vise...hooked up lines and injecters...all seem to be pooping and good mist comming out....not driblers lol
the dam PO had used silicone to try to seal them...the one thats was leaking was cranked in tight... others where not all that tight and came out easy.....that 1 1/16 socket made it easy ...thanks for that !!!
one more problem.....a bently manual is a bit far away for me right now...more due to the time it will take to get here... can some please tell me the tourqe specks for injecters on a 1.6 td ?
and thanks again for the help... im sure ill be back again...and again .. lol
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well i have the injecters out....the one that was leaking was leaking past the treads....i ran the car for a hour to see if it would clear up after washing the area....i pit my IP in a vise...hooked up lines and injecters...all seem to be pooping and good mist comming out....not driblers lol
the dam PO had used silicone to try to seal them...the one thats was leaking was cranked in tight... others where not all that tight and came out easy.....that 1 1/16 socket made it easy ...thanks for that !!!
one more problem.....a bently manual is a bit far away for me right now...more due to the time it will take to get here... can some please tell me the tourqe specks for injecters on a 1.6 td ?
and thanks again for the help... im sure ill be back again...and again .. lol
I assume you mean injector to head with new heatshields, well I think it's about 52lb ft. However, with new shields just nip them up by hand until you feel the shield give way, and then for the resistance to begin to build again. Only do max if they leak. Note sometimes they leak to start with, then within a few days stop.
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ahh shame to say...with the old heat shields..i live in a small a$$ town far from a dealer that caries any VW parts....so i make due till i go to the city and get the needed parts...but i get to do lots of jobs twice....so they must be good? lmao
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ahh shame to say...with the old heat shields..i live in a small a$$ town far from a dealer that caries any VW parts....so i make due till i go to the city and get the needed parts...but i get to do lots of jobs twice....so they must be good? lmao
Search for my instructions to reuse. Use 'Mole' clamp grips a 3/8ballbearing and aM17/M19 nut.Redistort so about 1mm gap when shield on end of an injector.
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darn didnt get that last post in time..lol oh well.its back together and has never run better....cleaned all threads and tourqed to 50 ft,lbs...no leaks ... did a hillbilly pop test...all sprayed the same as far as i could see...no dribles anyways....now onto all the other crap i have to do lol
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If the heat shields leak you could end up with a really stuck injector or possibly the head could burn where the injector seats.
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oh cheer me up!!! lol they where suposed to be new...but once tourqed thy are used...im kinda new to these small deisels...im going to try to run it as is for now....any thing i should watch out for? some thing might tell me if somethings going wrong?
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If the heat shields leak you could end up with a really stuck injector or possibly the head could burn where the injector seats.
Surely if the diesel leaks up through the threads it will lube them. Only if diesel leaks from offtakes and sits in a prefectly sealed thread will it dry out? ... Maybe.
Can you please explain how the head burns under the heatshield. Surely you'd need flames coming up the threads.
Noone ever got back to me about how many of their single use heatshields have leaked, nor how many single use heatshields allowed injectors to stick in. ::)
I also have an announcement re heat shield reuse. I recently had one of my ancient shields fail. After an initial panic I bought all I could afford with the change in my pocket... 2 @ £3.20 each. Nearly $5 a piece. :o I shall create a thread to explain why I'm more relaxed about the whole thing [shield failed outside the engine ;D after about 12 reuses]
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Never seen a head burn under the heat shield but I've heard of it ;D. Plus it kinda makes sense, if you have a gap right there and lots of fire..........it might have more to do with lack of maintenance+corrosion+heat.
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Never seen a head burn under the heat shield but I've heard of it ;D. Plus it kinda makes sense, if you have a gap right there and lots of fire..........it might have more to do with lack of maintenance+corrosion+heat.
As well as the classic leaning on the injector and breaking the boss off, I wonder if anyone in their efforts to stop leakages have tightened the injector through the ledge that holds the heatshield, snapped it off or merely cracked it or bent it out of shape, leading to those symptoms... :-\
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Mark, are you really one to be giving injector advice?? LMFAO.
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I had to torque my injectors to well over 100 ftlbs or they would come loose. Didn't seem to have an adverse effect, altho I haven't pulled them sense. :-X
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I had to torque my injectors to well over 100 ftlbs or they would come loose. Didn't seem to have an adverse effect, altho I haven't pulled them sense. :-X
Um, why where they coming loose? You used new heatshields? I've never ever heard of them coming loose, usually people put antiseeze on the threads so they won't get stuck in.
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Mark, are you really one to be giving injector advice?? LMFAO.
Based upon what?
I've never had injector failure, never had glowplug melt down. I've never broke an injector out.I'm the only one on two VW forums that worked out that expensive injector adjusting washers were simply a waste of money, [Even the Mercedes Guru's got that wrong :o]; that properly manipulated heatshields can be reused safely, that there are potential gains available from lower injector pressures, rather than going higher...
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that there are potential gains available from lower injector pressures, rather than going higher...
please explian....i know im interested...
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that there are potential gains available from lower injector pressures, rather than going higher...
please explian....i know im interested...
Higher break pressures were in part to help overcome nozzle faults, and part to allow for a quicker engine, ie faster burn of more fuel in conjunction with the additional air of the turbo.
In a swirl chamber, higher injection pressures, giving finer and finer sprays may develop penetration issues when fired across flow of compressed air. Conversely, successful finer sprays can lead to 'better' combustion, ie quicker, but this can lead to higher peak pressures and temperatures and also increased Nox, increased heat loss through chamber.
Lower pressures may give better penetration and perhaps a longer burn due to the larger globules of fuel, giving a longer torque, lower max temps, less heat loss lower Nox, quieter engine. Less power absorbed in injecting, and better fuel economy when cruising.
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so better in dayly use...long engine life....so would the higher pressure be better for high perfomance then? on and engine that wasnt ment to have a long life ...just hp?
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so better in dayly use...long engine life....so would the higher pressure be better for high perfomance then? on and engine that wasnt ment to have a long life ...just hp?
Probably yes on average, however, engines are funny things and some take a lot of 'abuse' and don't wear at the same rate as others. Some are born to be trouble. I call it the Tom, Dick and Harry syndrome, but if I use the film Christine to simplify; some engines are born to be bad. Clean burning of fuel and general engine care helps all engines though.
So many engines get killed off because of poor bodies. At least with these old diesels there is a chance of rebirth as a generator.
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lol i grew up with detroit deisels....2 strokes....these 1.6 td,s are way different.....but i have 4 of them now...i do want to try one in a boat....i think the power/wieght is just about right for a small speed/cruiser