I'm hoping this link works. Never tried it before. Rigged my injectors up to see if they firing or not, because car won't start but will crank. Anyone see any issues with pattern - ie, too weak etc. If looks ok I suppose I can eliminate fuel supply system. Ignore name. Needed name for you tube.
I'm hoping this link works. Never tried it before. Rigged my injectors up to see if they firing or not, because car won't start but will crank. Anyone see any issues with pattern - ie, too weak etc. If looks ok I suppose I can eliminate fuel supply system. Ignore name. Needed name for you tube.
Nodge68
Well-Known Member
The injectors are spraying well enough to run the engine.
Seeing the injectors spray eliminates many items.
Actually I'm struggling to come up with things to eliminate.
If it's getting fuel, it just leaves air it's not getting.
Try starting the engine with the inlet manifold off, and see if it fires.
Seeing the injectors spray eliminates many items.
Actually I'm struggling to come up with things to eliminate.
If it's getting fuel, it just leaves air it's not getting.
Try starting the engine with the inlet manifold off, and see if it fires.
Ian M in France
Well-Known Member
Try putting 3 back into engine and see if it tries to start and also see if the one left out is still working
Those injectors are the ones I cleaned. When I removed them again after they didn't fire the engine the wells were full of diesel. Since we know they spray ok surely it can only mean that the compression in the combustion chamber was forcing the diesel up into the wells. Wouldn't;t that loss of compression mean no firing?
The most likely explanation for that must be that the injectors were not crushing the copper washers enough to provide a perfect seal.
The washers were new (as were the O rings), but they were supplied by a local garage who said they were from other model stock (Discovery or defender). he said they all used the same washers. Now I thought they looked fractionally thinner, but I just assumed the old washers had deformed under pressure and that was the cause of the (very) slight difference in appearance. I also assume that when I tightened down the collar nuts it would not matter, but what if the injectors would not go down far enough to crush a washer that was fractionally thinner?
I'm asking if anyone has ever seen or heard of that. Also, it seems as if this could be solved by doubling up on the washers.
The most likely explanation for that must be that the injectors were not crushing the copper washers enough to provide a perfect seal.
The washers were new (as were the O rings), but they were supplied by a local garage who said they were from other model stock (Discovery or defender). he said they all used the same washers. Now I thought they looked fractionally thinner, but I just assumed the old washers had deformed under pressure and that was the cause of the (very) slight difference in appearance. I also assume that when I tightened down the collar nuts it would not matter, but what if the injectors would not go down far enough to crush a washer that was fractionally thinner?
I'm asking if anyone has ever seen or heard of that. Also, it seems as if this could be solved by doubling up on the washers.
Ok. I will have a go. What's the thinking behind that if you don't mind me asking?
Ian M in France
Well-Known Member
not too sure about the td4 engine but might be if there is a cam and crank sensor the ecu checks timing is okay, with compression if you are right on the edge of being okay the compression might just push it over the edge, a long shot but if you have fuel and compression it should run, other thing is turning over a engine with compression takes more out of the battery, if the volts drop might stop the injection system working
Thanks. Worth trying for sure.
Awesome. I shall certainly do that. Any thoughts on using two washers instead of the one? I mean reason not to. I suppose it would change position of nozzle tip in combustion chamber. I'm wondering if there is something very basic I have missed or done wrong.
Injector seals are a P&%£K of a thing on the TD4 engine, and if you don't get a good seal you don't get compression and the damned thing won't run. Mix up some dilute fairy liquid and water in a skooshy bottle, dowse the injectors in this solution, and try to crank it. Theoretically if, as is most likely the case, you have a compression leak, the car should blow bubbles at you on the offending cylinders... Don't go to far with the soapy solution lest you hydrolock the blerry thing.
Ah, good idea. I have been retracing my steps and I now think I didn't;t tap the injectors down far enough when I put them back in. I was being gentle on account of the top being fragile and thought I could rely on tightening the collar nuts to force the injectors right down. But on reflection that was a bad call, because they only 8 mm and I was wary of stripping thread. First thing I do tomorrow is make a 'thing' so I can hit the top of the collar rather than the top of the injector. Also going to heat the copper washers to make them soft, as advised above. If that don't work I will get out the fairy liquid. Thanks.
Ian M in France
Well-Known Member
Had you done anything to the car before or did it just decide not to start one day? did it normally start really easy? Did it try to start (fire but not run)? Normally if the car is going okay one day and just will not start the next would not think it was injector seals, but for a diesel to run you need diesel and compression and you seem to have diesel so injector seals look likely
It was playing up with difficulty starting and an odd noise. SO I took the injectors out to clean them and put them back and then got no start at all. I tried another set of injectors I had not touched, but same deal. Anyway, I am about to reseat the injectors in the video, but this time as firmly as possible. So will find out if it was lack of compression soon enough I guess.
Ignore the bit about smoke - that was coming from pipe that egr normally connects to. So. If smoke is coming out of that egr exhaust it means injectors are firing in the compression chamber. Enough air must be getting in because the air intake manifold is off.
Battery recharged to 12.68 and not making any difference - still turning but no ignition.
I whipped the cam sensor off the donor vehicle and did a swap - no difference.
What else could be preventing it from firing?
I thought possibly the low pressure fuel pump, but I already know that fuel is being delivered to the high pressure pump and then to injectors. Is it possible that not enough fuel is being deliver by the low pressure pump to generate sufficient pressure from the high pressure pump, even though injectors are firing? I have no way of knowing if the pattern in the video is spot on or slightly off. Suppose the low pressure pump is cutting out intermittently and causing a break in the firing sequence, or a loss of pressure. Possible?
Battery recharged to 12.68 and not making any difference - still turning but no ignition.
I whipped the cam sensor off the donor vehicle and did a swap - no difference.
What else could be preventing it from firing?
I thought possibly the low pressure fuel pump, but I already know that fuel is being delivered to the high pressure pump and then to injectors. Is it possible that not enough fuel is being deliver by the low pressure pump to generate sufficient pressure from the high pressure pump, even though injectors are firing? I have no way of knowing if the pattern in the video is spot on or slightly off. Suppose the low pressure pump is cutting out intermittently and causing a break in the firing sequence, or a loss of pressure. Possible?
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Injectors not seated correctly. Simply put a diesel needs three things to run, air, fuel and compression. Were it an ECU problem like a cam sensor it wouldn't be pulsing the injectors regardless of where they are located, be it in the bore or in the air.
Since you're getting fuel, your electrickery is ok so sensors are off the list of culprits, as is fuel, since the manifold is off, there's no air restriction, leaves one thing from the list of necessities for a diseasel engine to run, compression. Where can you lose compression, valves, glow plugs, piston rings and injectors. Given you have disturbed the injectors, and it was working before, it's current inoperability is a consequence of recent actions. It's beyond impossibility that you've coincidentally damaged all four cylinders to the point of having insufficient compression to fire through broken valves/rings/glowplugs.
Were it only one or two culinders damaged / down on compresion, it'd be running on two of three cylinders and missing on the damaged one, but it's not firing at all, so it's a sytemic fault across all four cylinders.
When you eliminate the impossible, whatever is left, no matter how improbable, must be the truth, and going back to out diesel needs triangle, we've eliminated air, and fuel, so it must be compression that is your issue. Given it's across all four, the only thing that's been disturbed on all four cylinders in the injectors. Ipso facto it's only the injectors that can be causing your lack of compression, resulting in a lack of ignition.
It's not an expensive repair, but injector seals can be a right C%&T to sort....
Since you're getting fuel, your electrickery is ok so sensors are off the list of culprits, as is fuel, since the manifold is off, there's no air restriction, leaves one thing from the list of necessities for a diseasel engine to run, compression. Where can you lose compression, valves, glow plugs, piston rings and injectors. Given you have disturbed the injectors, and it was working before, it's current inoperability is a consequence of recent actions. It's beyond impossibility that you've coincidentally damaged all four cylinders to the point of having insufficient compression to fire through broken valves/rings/glowplugs.
Were it only one or two culinders damaged / down on compresion, it'd be running on two of three cylinders and missing on the damaged one, but it's not firing at all, so it's a sytemic fault across all four cylinders.
When you eliminate the impossible, whatever is left, no matter how improbable, must be the truth, and going back to out diesel needs triangle, we've eliminated air, and fuel, so it must be compression that is your issue. Given it's across all four, the only thing that's been disturbed on all four cylinders in the injectors. Ipso facto it's only the injectors that can be causing your lack of compression, resulting in a lack of ignition.
It's not an expensive repair, but injector seals can be a right C%&T to sort....
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Nodge68
Well-Known Member
You're getting fuel injection, so it's not the cam sensor, as a failed cam sensor prevents injection.
A blocked exhaust will prevent it running, so the turbo shaft could be stalled, preventing the exhaust gas from escaping. The CAT could also be blocked, which also stalls the engine, but normally allows it to start briefly.
You've seen the injectors spraying, so that basically eliminates everything electronic or fuel related.
There should be an error code with the amber light though, so a code read is a sensible thing to do.
Taking a break for 48 hours to think about it.
I hope you are right.
Still, what about this: there is a faulty high pressure fuel pump regulator and it is firing too much or too little diesel through the injectors which is messing with the mix and causing it not to fire.
If that isn't it, then the only thing I can think of is that when I tightened down the injector sleeves after cleaning them I went too far, which meant I effectively shortened the body of the injector and the washer isn't enough to completely close the gap. I did all four the same. But the tolerances involved in getting the seal would have to be very very fine for a gap to be there from that.
To test that I am planning to add another copper washer to each injector.
Apart from that, what does eventually tend to get the injectors properly seated? Is there some magic gunk I can apply?
I hope you are right.
Still, what about this: there is a faulty high pressure fuel pump regulator and it is firing too much or too little diesel through the injectors which is messing with the mix and causing it not to fire.
If that isn't it, then the only thing I can think of is that when I tightened down the injector sleeves after cleaning them I went too far, which meant I effectively shortened the body of the injector and the washer isn't enough to completely close the gap. I did all four the same. But the tolerances involved in getting the seal would have to be very very fine for a gap to be there from that.
To test that I am planning to add another copper washer to each injector.
Apart from that, what does eventually tend to get the injectors properly seated? Is there some magic gunk I can apply?
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Haven't got a code reader. From what I've read they don't seem to identify problems with unerring accuracy. Still, you're (genuinely) an expert, so what would you get by way of code reader?
I've got a thought regarding blockage: since the manifold is off, the pipe connecting the exhaust to the egr is open and exhaust smoke blasts out of that when I try to start.
What if I were to block that off and look at the exhaust from the rear. Since it is white smoke at moment it should give me an idea of whether there is a blockage
