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Engine Specific Info and Questions => IDI Engine => Topic started by: ross1905 on June 20, 2016, 01:16:31 pm
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Hi, i know not my VW this time but basically the same pump! I have recently stripped and completely re-sealed the Bosch VE on my little n/a 205 as it had a partially seized vane pump. Problem is it will now not start or run whatsoever whereas it just about did before. I'm perplexed as I'm 99% sure it's assembled correctly, I'm very familiar with these pumps, have had them to bits many times before and I understand how they function.
Spent hours troubleshooting and have got no where with this one. Camplate is in correct, plunger isn't stuck, delivery valves clear (have since swapped these out), stop solenoid lifts fine, throttle arm at correct position etc etc.
To the point, all I've found is that when I fit one of the Lucas pumps to the car, the primer will stay solid once it's primed. I cannot get the primer to stay solid on this VE. It looses pressure within seconds and there are air bubbles from the return line regularly when priming. There's also a quiet squeak from the pump when priming, sounds like a leak but no diesel leaks. Maybe air getting in though? If you take the injection lines off and crank it over, it dribbles fuel out of 3 delivery valves and only 1 valve actually has any pressure (hence refusal to start). Ime, even with a very small air leak to the pump, they normally still fire up. I believe the dribbling delivery valves and the fact it won't hold pressure from priming is related but struggling to find why this is happening? I didn't use genuine seals this time if that matters?? Thanks so much to anyone who can help!
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have you tried installing an electric pump? did you lube the vane pump with grease maybe the vanes are sticking because of that, i might just take the electric pump, or a tow start to get it going.
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How does a vane pump 'partially seize'? I've only had one that had issues and there was nothing partial about it.
After the partial seizure, did you replace the fuel distributor, delivery valves, and injectors? If not, how do you know they weren't damaged by the swarf?
Did you install the vane pump outer ring the right direction? If it's flipped over, it will push fuel out of the pump rather than pulling it in and it will not run.
I have no idea if the non-Bosch seals are an issue. I guess that depends on the quality of them, which is a complete unknown. The cost of an authentic Bosch rebuild kit is <$20. Considering how much labor goes into changing the seals/o-rings and how much work it is to R+R the pump and tune it properly I can't imagine wanting to risk unknown quality to save <$20. That strikes me as seriously false economy.
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I am going to say Partially seized Vane Pump means one or more of the vanes were actually sticking in their slots and not moving out to the edge of the pump to push fuel. Is that a correct or incorrect assumption on my part, about the part?
I hate to say this but I too was under the impression I could rebuild it wrong. With that going on in my head I sourced out a ton of reasons why my engine was not starting and eventually I landed on the place you always have to go to when this happens. What was the last thing you were doing to the engine before this problem reared its ugly head? I would say you have to go back and prove to yourself that the IP is indeed built the proper way. Like Libby suggests some parts are flipable but don't work if you happen to flip them.
Sorry man that is what I would be doing just to clear that question up. If the Vanes don't pressure up the first part of the pump then the rest and fuel coming in doesn't happen either. Did you fool, I mean tap the regulator in the front down and out and clean it up? That is a hard one to correct without a measurement device on the IP itself on the out bolt. You may need to drive it down a 1/16 of an inch or so at at time to get it to run.
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I am going to say Partially seized Vane Pump means one or more of the vanes were actually sticking in their slots and not moving out to the edge of the pump to push fuel. Is that a correct or incorrect assumption on my part, about the part?
Ah, that might make some sense. I've had the vanes stick, but wouldn't have called the pump seized. The one vane pump I had seize, welded itself to the cover plate, sheared the pump mounting bolts in the case, sheared the sprocket key, welded the sprocket to the main pump shaft, etc... It was a mess.
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Libby I think that qualifies as a complete siezure of the internals of the IP. That's what running boost will do for you.
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I don't think it had anything to do with boost. The only parts seized were the vane pump center to the cover plate and the pump sprocket to the main shaft. I actually managed to get it started like that and drive it home about 4 blocks... :o I still have the vane pump center hub that is welded to the cover plate in my pile of souvenirs.
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Thanks for the replies guys, I will strip it again and re-do with genuine seals in the hope it will get rid of the supposed air leak 'squeak' it has.
Yes, by partially seized vane pump I mean a couple of the vanes sticking in the rotor, that's all. No damage.
Its a possibility the stator could be in the wrong way but I doubt it, we'll see.
If you mean what I think you mean - I removed the pressure regulator itself, changed the seals and re-fitted it. I understand IPP can be adjusted by tapping the top of this when running on a test bench.
I tried tow starting it and it would inject and burn fuel but wouldnt run on its own. With the lines off and being towed all the d.valves began to spray fuel evenly but still wouldn't run. Seems to me an air ingress/internal pump pressure issue somewhere.
Some vanes could have seized again in the day or so the pump was left empty before it went on the car but i'm not so sure.
I've always re-assembled pumps with clean diesel and nothing else apart from a dab of grease to hold the leverset return springs in the head.
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If you have a clear line for supply, you can watch it while cranking to see if the vane pump ring is in upside down. If it is upside down, the fuel (or bubbles) will flow away from the pump while cranking.
Any chance you installed the camplate 180° out? How about when installing the pump, any chance it is 180° out from the cam?
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Wouldn't it be a HOOT if he did both 180 outs and it ran just fine.
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Nope no common mistakes here. Nothing is out of time, it'll run whilst towed quickly - soon as you dip the clutch and try and rev it it'll die and wont restart. Air bubbles regularly flow from the return, nothing back down the feed so stator is probably in correctly. Has got to be an air or pressure problem I think. I'll rebuild again with genuine seals this time and see where we get, first time using aftermarket seals to be honest, never had an issue with bosch ones. May well be the mistake not to be made again.
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Don't give up yet. Re-doing the seals may not do anything.
Can you get all the air bubbles out with an electric fuel pump or mightvac; any serious restriction in the inlet fuel line (all the way back to the tank), check the copper seal on the pump inlet banjo (I accidently had 2 there once and it sucked a lot of air); check/turn up the fuel setting and/or idle.
I sounds like it's barely getting fuel
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Taken it to bits again and every single piece is in correctly - except possibly for one, hey!
It seems the problem (or part of it) is me being my own worst enemy! Many thanks to libby for bringing up that the stator/vane pump ring could possibly be flipped...it makes sense as I rushed this pump back together to get the car going again quickly (which backfired as we know) ;)
At the time I had a thought and really didn't think about this being a strong possibility for its complete refusal to run; it starts to make some sense now. Here's hoping the original problem can now be fixed also!
In the photo below is how I lifted the stator out from the housing - if you look in the housing you can see its position would be in backwards/flipped over...DOH
Now just to fit it to the car again, fingers crossed!
(http://i90.photobucket.com/albums/k257/rossikeeling/stator_zpstyqytomj.jpg)
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Don't beat yourself up over this. Just learn that it is always, and I do mean always better to slow down, do it right the first time and save all the time you spend chasing down the stoooopid thing you did during the rush job. I can't even begin to tell you the dumb things I have done in the past 30 plus years fixing engines. I think most of the time it was me, sometimes the wrong part and even less times because I just didn't know what I was doing as it was the first time I did it.
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Okay guys, you're probably getting as bored of this as I am!
Flipped the vane pump ring over to the correct way, re-assembled again made sure everything was perfect.
Fitted to car, everything is exactly the same! Will not run or pump fuel.
No injector lines fitted, throttle flat out, it will dribble fuel erratically when turned over.
Delivery valves out, fuel pours from every port but at different rates! Some will have more pressure than others, and its completely at random which one has more than another!
Removed the center nut to the pumping chamber (d.valves back in), and get lots of nice, clean big pulses of fuel from here at a steady rate as you'd expect.
Makes me think there's an issue with the head? Already tried countless different sets of delivery valves, no difference.
Still, even if it is the head itself at fault - why? Remember, this pump did actually run before I pulled it apart, cannot fathom what the issue is here!
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Are you sure about getting that little tab into the delivery collar just right? Or is that allowing the fuel to go back into the pump instead of out the back end as it should? You did say you get nice big pulses of fuel from the back of the pump.
Did you air any of the pieces where something might be stuck in a port someplace? Those holes in the head going to the delivery valves? Are those plugged?
Other than those ideas I am tapped out tonight. To many different things going on in the brain about work today.
I have been multi-flogged.
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Do you have a steady stream of fuel out the return? Do you have the in and out banjo bolts in the correct place? Any chance you put the control collar on the rotor on backwards?
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Yes good flow from the return, in/out banjos are the correct type in the correct places. Can pop the top off again to double check the collar but that should be correct, especially as this is the second time it's been rebuilt. Personally find it odd how it'll pump fuel out of the pumping chamber no problem with the centre plug out but gets upset when trying to flow through the delivery ports. There can't surely be anything wrong with ports the head, it isn't even mechanical...everything was and is very clean.
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ross1905, The way I read the information so far you have the front side of the pump working and it is delivering to the secondary. The problem is that stream you see coming out the back plug is not getting compressed as the cam hump comes up. My initial thought is still on that control collar spilling the fuel to the inside of the pump. That action is tied to the parts under the top of the pump right? Those two springs that you have to goop up with Valoline to get them to stick in the head have to stay in place when you bring the head down on the pump shaft. I goo up the other springs too the big ones to keep them from moving as well. Vasoline is just petroleum jelly and the engine will love to eat it like dark chocolate so don't hesitate plastering it in those holes.
Could you just have the fuel screw out too far? I have done that in the past. You need to back it out to get that top cap on don't you? Maybe it is just short on fuel and not compressing enough to fire it up.
Seriously thinking on this one for you because it is so easy to forget something or overlook the right position of a piece on that IP.
Keep in touch.
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Thank guys, we've got somewhere!! (took some provoking!)
I put the pump on a crate engine I had as it's easier than pulling the car apart each time.
Rebuilt again, haven't changed anything I've ever done apart from getting rid of the KSB, changing the timing piston and capping off the front as I didn't need a KSB on this car.
So after a lot of cranking and a lot of starting fluid I finally got it to fire up. It runs fine, smooth, everything working as it should.
However, it doesn't have a stable idle (unless it's at around 1500rpm). It also is very lazy to rev - as in if you pull it flat out (max travel screw removed) it will redline but it takes a while to build its way up there (almost like holding the throttle half way down and waiting). Terrible throttle response.
No amount of playing with the max fuel screw cures this, just more smoke and then a 3000rpm idle haha! - its almost like the control collar isn't being moved far enough.
Played with the throttle arm positioning on the throttle spline, no difference.
All I can think of is it's all to do with the governor system surely? I've always been skeptical as to what EXACTLY the effects are of the position of the "governor adjustment shaft". Normally I just count the threads and put it back where it was and its fine but this is the only thing I think could cause this - hear me out:
AFAIK - The static position of the sliding sleeve on the governor determines how far back the starting lever sits when the pump is stationary. This determines the positioning of the control collar for starting. If the sleeve is screwed in too far then the starting spring cannot allow the starting lever to 'lean' back far enough to move the control collar far enough for sufficient starting fuel - yes? (hence the terrible starting maybe?)
Then adding to this, once it has finally started and the flyweights are spinning, it has started to move the sliding sleeve slightly to push the starting lever back to the idle position (which is now too low hence the need for more on the max fuel screw to get it to idle). Then, as the throttle arm moves the tensioning lever for more fuel and the pump speed rises, this causes the flyweights to come out farther and push the sliding sleeve against the leverset to start to cut fuel delivery. As the governor shaft is set in too far, it is cutting fuel too early and you're constantly fighting against the governor hence why the pick up is so lazy as I believe it is stretching the main spring almost all the time. So all I can think of is to back the governor shaft out somewhat...what do you think to my theory? Sorry for another huge post :P
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seems like more fuel screw would be in order,
I had to adjust fuel screw and the idle/throttle shaft till I found the right balance after pump reseal
here is some info on the nissan LD20 pump that is similar to the VW application (don't confuse w/ the LD28 info)
: https://docs.google.com/gview?url=http://www.waghornswood.net.nz/Manuals/Vehicles/Nissan/LD20_LD28_Manual_pdf/ld20_ld28_manual_ef.pdf may answer some questions and show how the governor operates
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So after a lot of cranking and a lot of starting fluid
This is what is known in the internet world as a fail. For all those reading at home, you do not use "a lot of starting fluid" in these older IDI diesels that have a steel pre combustion chamber press fit in an aluminum head. Especially ones that are this old. Cracks in the pre chambers, broken pre chambers, cracked rings, and more fun stuff can result.
If you have to things that are a lot less explosive like wd40 should start the engine in a little safer manner. Still, do not spray so much, just mist, you can hydro lock and bend stuff that way too.
You can now return to your regular scheduled reading.
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I've done work on these IDI diesels for more than 20 years now and have never once used starting fluid. I've always just fixed the starting issue rather than using an infected band-aid. These are simple engines and start without issue provided just a handful of things are correct.
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I agree Libby, But to be a master of that handful is the key. I don't think it takes 20 years to do that but my guess is that those without a lot of diesel experience find it more difficult than it really is. The basics start with throwing out much of what you know about gassers. Once you switch to the correct mindset about tolerances, torque and timing procedures all you really need is a good Bentley and things fall into place. At least that is how it works for me.
I was finishing up my repair of my engine and was tightening up the head and a buddy drove up, I was doing it in the street, and he was just marveling at how it was no big deal for me to pull it all apart and put it together AND have it run again. I look through Craigslist here and generally there are at least three or four descriptions that mention pulling off the timing belt or rebuilding the engine and now it won't run. OR trys to start but it won't. If I had more time and money I would buy them all and flip them for a few hundred just to have them running.
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Starting fluid does not help diagnose a diesel (anything it might reveal could have been found out more effectively in other ways), it certainly does not assist in any repair, and it can cause significant damage to IDI engines. There is not any reason to use it and significant reason not to.
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Thanks for the replies, I too have worked with these years and know the do's and don'ts with starting fluid.
Everything said is correct and I don't use it on these, however, the pump's being tested on a crate engine which is useless for anything other than this purpose - so I care not about the damage that can occur (the engine was initially scrap). It got it running, though without flattening batteries. This at least gives me an idea of what's going on with this pump.
Anyway, with that cleared up I'm going to move the control lever a spline each way (again) to see if this gets anywhere and possibly take a look at the governor shaft. I think we can all say that it's likely to be down to the positioning of the control collar (it's just finding which part is influencing it to be in the wrong position at the wrong times!) I'll report back asap ;)