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Engine Specific Info and Questions => IDI Engine => Topic started by: srgtlord on July 11, 2016, 03:10:28 pm
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So I pulled a diesel motor out of a 1981 Caddy pickup truck and put it into my 1992 MK2 4 door Golf. Wired everything up, turned the key and the car was hard to start but once started it started and went straight to full throttle. I think the reason why the truck was parked was because of this throttle issue. It appears that someone has opened up and fiddled with the injection pump... Any ideas as to how to get this thing to idle? FYI it appears the fuel screw has not been messed with as the collar is still on it
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Sounds to me like someone was turning on that front screw that controls the governor, governor? ;D
I wonder if you loosen that lock nut and start turning it so it applies a force on all that mechanism under that cap as those free weights are spinning like a top if that will help? Maybe those weights are stuck and not swinging out as they should???
Cap off to check? Seems a quick fix my friend.
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I think I may have been wrong about someone messing with the pump.This is what it looks like with the lid off. Very rusty under there and the weights dont seem to be stuck but the rest of the governor assembly seems to be stuck. Is there anything I can do to unstick the governor assembly?
(http://i692.photobucket.com/albums/vv285/srgtlord/pump_zpsd4sprw3s.jpg) (http://s692.photobucket.com/user/srgtlord/media/pump_zpsd4sprw3s.jpg.html)
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I knew it!!!! So what part is not doing it's part? When those weights move out they are supposed to move the tip of that shaft into the control mechanism. Does that part not move when the weights spin?
How much do you know about these pumps? I think you know enough to make this part free itself.
On the front of the pump there is a locking nut on the shaft that turns into the body of the pump case and supports that flywheel assembly. There are exploded views of it on the FAQ section I believe.
You need to get the nut to loosen up and then get the shaft out of the body of the case to clean up all the parts. There in lies the problem. The lock nut and shaft are ccw threaded. So you need to hit the slotted part of the nut with a punch like you are putting it on in order to actually get it off. Then when you go to remove the shaft count the number of times you turn it completely around. I don't care if you count half turns or full turns just count them and put it back together with the same number. Otherwise you might be limiting the high end revs of your engine.
It would be a serious problem if you couldn't get above 2500 RPMs.
I think once you get it apart, clean it up and reassemble you can give it the spin test by lightly installing the pulley and turning it. Don't reef that nut on the front of the pump or it is a pain to get it off. But you already know that one, correct?
Hope that gets you up and running at a better speed.
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Well turns out that I was able to free the governor without taking the pump apart. There is a tiny hole in the governor shaft and I found the tip of a punch would fit in there. I tapped it lightly and it came free. I figured I had 2 other pumps kicking around in case I broke anything ;) Off to my pile of spare VE pump seals to put the lid back on. Ill let you guys know what happens.
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Well it no longer is stuck at full throttle but the engine is struggling to run. I'm going to do a compression test and see what's up.
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Well the harbor freight tester was garbage.... Peice of junk didn't work, returned it and the second one didn't work.... So I figured I would try another set of injectors I had kicking around... nope... car still runs like garbage... something is seriously wrong as the engine is only firing on 2 cylinders... I think it's time to pull the head or get another compression tester....
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Do you have fuel to all the injectors?
Run diesel purge through it. There's a good chance it will need a full tear down though.
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Yes there is plenty of fuel being delivered to each cylinder as I found out when I opened each injector line. I'm going to try to borrow a working compression tester just to see how much may be broken on this
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Well turns out the cheapo harbor freight tester never holds the pressure but dies give a reading... cylinder 1 2 and 3 read 100 psi. Cylinder 4 read 150... Not sure I'd I can trust the gauge at all... I'll buy a decent tester tomorrow just to be sure
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Turn it over by hand and see how hard it turns.
At those numbers it should turn over very easily.
If it wants to turn backwards the compression is good.
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Said in a different way. If you can turn it over by hand and do not feel any resistance from compression, that kicking back feel, then you can trust those low numbers. If however you do feel resistance to turning it over by hand then suspect those numbers as incorrect.
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I definitely feel resistance when turning the engine over by hand. Either the gauge is wrong or something is really fubarred
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Years ago I had good luck with an old 1.5D na pulled from a caddy sitting in a field for 10-15 years. It run well with new headgasket and oil change..
Anyways when my old head blew up after coolant loss from a hole in hose, it still ran on 3 cylinders. When I replace the head it was obvious which cylinder didn't fire. The non-working cylinder was very clean with the unburned diesel cycling though
Just thinking if you have low compression on 1-2 cylinders you might be able to which cylinders are bad by how clean the head is for them
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Well turns out the cheapo harbor freight tester never holds the pressure but dies give a reading...
A compression gauge that does not HOLD the reading is going to be wildly inaccurate, giving a reading MUCH lower than it really is. A tester that does not hold the pressure will be compressing the air in the entire gauge/hose setup with each cycle of the engine. Under those conditions, the gauge/hose will be making the compressed volume several times larger than it should be and consequently the shown pressure will be a small fraction of the real compression pressure.
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Well Napa compression tester came in. Cylinder 1) 380 Cylinder 2)390 Cylinder 3)330 Cylinder 4) 340. The compression looks on the lower side of things but it should fire ,right? I'm thinking something is borked in the pump. Time to pull off the pump and swap with one of my good working pumps.
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Good numbers would be floating around 480-450 so yours are low. Would it keep it from running? Maybe if in a cold climate but not likely right now. I can't remember if you have done a check on valve clearance on this head or not. Maybe they are out of adjustment too given the lack of maintenance these old neglected cars receive.
Being nearly 150 off on those last couple may be keeping the engine rolling although the firing order should account for that.
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I have not checked the firing order or the valve clearances. Is there a good how to guide for checking valve clearances? I have never had to deal with a mechanical head before.
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If everything else was correct, it would start and run fine with those compression numbers. I've run worse than that and had no trouble with starting/running down to 15°F or so.
Considering it sat for a while, the compression will likely come right back up after running for a bit.
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With numbers like that, the crank probably tried to turn backwards when checking the compression by hand.
At least above 360.
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Well the firing order is set by the type of engine it is. For the 1.6 L I have, the order in which the cylinders compress and fire the diesel is 1 - 3 - 4 - 2 with #1 on your left as you stand in front of the engine bay. So, if the 3 and 4 are not up to doing the job you might see a performance lull as they are trying to continue the crank along its way one after the other. #3 fires the crank goes down and #4 comes up and is supposed to fire and send the crank on down again when the #2 would then fire.
The measurement of the valve clearances is a little involved in that you need to pay attention to if the engine is cold or hot. Clearance cold is different than when hot. Then you need some feeler gauges that you can get under the cam lobe and the cam follower with the cam lobes up and not pressing on the valves. Again following the firing order allows you to turn the engine over 180 degrees and get to each one at TDC.
Honestly, you don't have a Bentley for working on the car? IT IS Time to get one. Even my local Library has one for my car and several others that give more general information on VW's. I can get up to 7 pages copied free of charge. Look into that resource as a temporary filler for processes like this.
I can do pictures and upload to Photobucket but you need better than that.
But if that is all you can get I will do it. Let me know. We can go Personal Message with that.
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I have the MK2 Bentley but I can't recall seeing a section on mechanical valve adjustment but I'll double check in the morning.
I should have been more specific about checking the firing order. I meant checking to make sure the previous owner hooked up the injection lines to the proper cylinders :)
I think my primary focus will be getting a different pump bolted up and see if that makes a difference. I have a sneaking suspicion that the aside from the governor that was stuck there is probably bits of rust that are causing the pump to not deliver the proper pressure to all 4 injectors, even though there is indeed fuel being delivered.
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Not sure if the MK2 have that ability to change valve clearance. Didn't that go away with the use of the hydraulic head?
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Mk2 started in '85. The 85's were solid lifter. The change to hydraulic happened a year later with the '86+.
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Thanks for the history lesson. I don't follow the model changes very well.
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So I bolted up a good used pump and the car did the same thing. Ran like absolute garbage. I think this is pointing towards the injectors at this point. Any other ideas folks?
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So out of frustration I decided to crank it over a few more times, and it struggled to run but after about 10 minutes the idle evened out and it's running on all 4 cylinders :) So there was definitely something wrong with the other pump. When I pulled out the stop solenoid on the old pump there was some grime and rust on the plunger. So I'm happy with the end result for a motor that was sitting in a farmers field :)
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Might have just been the injectors not functioning properly for so many years. There isn't a lot of lubrication in those parts in the first place. I don't think there is a teaspoon or 5 ml worth really.
Glad you got er going. Now are you going to put the other pump on and try it?
It's OK to just say NO.
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I think I'll just leave this pump on and change the leaking throttle shaft seal. I think the original pump needs to be pulled apart and cleaned out before being put on another motor.