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  #1  
Old 08-06-2016, 12:47 PM
adamdrives adamdrives is offline
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Default Adjusting Pump Timing

Hey All, searched around but can't find a post that deals with the problem I'm having.

I'm in the process of restoring an '85 740 gle with the d24t motor. Right now, I am stuck trying to correctly time the injection pump. My timing was too high, so I slackened the three (I can only find 3, afaik this is correct) bolts and tried to "tilt" the pump outwards. I'm not sure if this should be easy, but the pump feels as if it's completely stuck. Finally using a prybar, I was able to gently rock the pump against the block, and it moved. Now, the timing is far too low, and I don't have any safe surfaces to pry against to try to tilt the pump inwards. What can I try next? The three bolts and mating surfaces have all been soaked with penetrant. I'm leery about getting my torch out near a fuel source, that would normally be my course of action near stuck surfaces. Any ideas? I have also cracked loose the high pressure lines thinking they might be creating some tension on the pump. Thanks in advance.

Adam
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  #2  
Old 08-07-2016, 05:36 AM
Goteborg Vapenfabrik Goteborg Vapenfabrik is offline
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Moving the injection pump with anything other than force you can apply with both hands may over tighten the injection pump belt. There is a better method using tools 5199 and 5201. Make sure the engine is at TDC by looking for the mark on the flexplate or flywheel. Using tool 5199 to hold the rear camshaft sprocket, loosen the nut holding the rear camshaft sprocket on the camshaft. The torque value is 73 ft lbs here, it's very tight. Tool 5201 is used with a 1/2" drive bar or ratchet to loosen the nut. Loosen the nut, keeping in mind that it's very tight. Once it is loose, retighten finger tight. You are now going to rotate the sprocket in the normal direction of rotation ( the camshaft must remain stationary). Rotate the sprocket with tool 5199 or your hand, keeping in mind that you are rotating the injection pump belt and the sprocket on the injection pump. While you are rotating the camshaft sprocket, watch the needle on the dial indicator, once you reach the value you are looking for, tighten the rear camshaft sprocket nut , making sure your injection pump timing stays in the right place. Once you have the nut tight enough it won't move get ready to retorque to 73 ft lbs, this is much torque for a hard to reach area. This method takes rotating the injection pump by hand out of the equation. Makes sure your injection pump timing belt is not too tight. Address that first before setting the injection pump timing.
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Old 08-07-2016, 05:43 AM
Goteborg Vapenfabrik Goteborg Vapenfabrik is offline
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Keep tool 5201 and the torque wrench at a right angle while applying torque to the rear camshaft sprocket nut.
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Old 08-07-2016, 10:43 AM
Goteborg Vapenfabrik Goteborg Vapenfabrik is offline
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The camshaft sprockets are fastened to the camshaft by screws, the inside of the camshaft being internally threaded, not nuts as I wrote in my reply. Good luck with your restoration.
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  #5  
Old 08-07-2016, 07:00 PM
adamdrives adamdrives is offline
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Thanks for that info, everything worked exactly as you described. Luckily the car came with a number of the diesel specific tools, I was able to get the timing into spec on the first try. I had trouble cracking the 21mm bolt on the end of the cam, but with the hood in the full up position it was much easier. Thanks again!

Unfortunately the car still doesn't start. There are a few different issues that are apparent now that I have been able to crank the car. There is a fuel leak somewhere on the underside of the injection pump towards the back of the motor. I am going to try snugging all the high pressure lines on the pump I cracked loose when I was trying to get the pump free again, but they already feel pretty tight. This area seemed to get wet after I cleaned the entire pump with parts cleaner to try to find the source. I will try tightening them again with two flare wrenches, one to counterhold the fitting out of the pump and one on the line nut. I hope that solves the leak issue. Other than that, the glow plug indicator lamp doesn't come on. Greenbook says to look for power from orange wire at control unit, I get nothing, so I will have to look more deeply into that. I also can't find a wiring diagram for what I believe is a coolant temp sensor somewhere near the rear cam sprocket. I remember having a hard time removing a connector from back there, but now can't find any connections. Either way, it's a relief to finally have the pump timed and the wiring harness (almost) installed. Hopefully tomorrow I will make more progress. Thanks again for your detailed responses.
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  #6  
Old 08-08-2016, 07:48 AM
Goteborg Vapenfabrik Goteborg Vapenfabrik is offline
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Without glow plug function on at least five out six, there's not much chance it will start. Also, regarding the main engine wiring harness, its eight wires , there may be a diagram for the engine wiring at k-jet.org. Haynes manuals for the 740 have a diesel engine wiring diagram. The sensor at the rear of the head is the temperature sensor for the glow plug system. A brown wire goes to it. This is also probably the best time to check all six glow plugs. You can get number six out by removing the rear timing belt cover and working gingerly from behind the head. Have a telescoping magnet ready to position the known good glow plug for reinstallation. Getting the tiny 8mm nut on glow plugs five and six to secure the bus bar isn't much fun either. Once you have verified correct timing, glow plug function and fuel, the only thing left is compression. Hope it won't come to that.
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  #7  
Old 08-08-2016, 03:23 PM
adamdrives adamdrives is offline
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I resolved the glow plug issue, I made a mistake when I re-wired the glow plug relay. As far as I can tell, the glow plugs are operational.

The car still doesn't start, but I have a new concern. The PO stated that he was selling the car because the turbo seized (this was true, but the wiring harness was also disintegrated). I rebuilt the turbo, but now I'm wondering if there could be an oil pressure issue that caused it to fail in the first place. With the oil feed bolt cracked on the turbo, there is no visible oil pressure when cranking the car. I checked the banjo bolt, and it looks clear, as does the feed line as far as I can see. When/If I am able to get the car running, I'd prefer to know that my oil pressure is ok, especially to the turbo.

My plan is to replace the oil filter, as that could create a restriction, and check/replace the oil pressure bulb in the dash, which does not come on. Other than that, is there anything simple I can look for? The oil level is ok.
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  #8  
Old 08-08-2016, 04:28 PM
Goteborg Vapenfabrik Goteborg Vapenfabrik is offline
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These engines don't generate oil pressure instantly. The engine will need to start for it to pick up the oil enough to build oil pressure.
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  #9  
Old 08-08-2016, 07:03 PM
adamdrives adamdrives is offline
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Ok. I hope you're right about that. I'd hate to ruin a freshly rebuilt turbo. I fixed the lamp in the instrument cluster and it stays on while cranking. In my whiteblocks pressure is usually built (and the lamp goes off) after 20 seconds or so of cranking.

I'm still fault tracing the no-start condition, starting at the top of the list in greenbook.
1. Injection pump solenoid--good
2. Injection pump sucks in air via fuel line or driveshaft seal--unknown
3. Fuel leakage--there is some seepage at injection pump high pressure line connnections when cranking. Tightening down the connections into the pump doesn't seem to help, I'm considering removing the pump and tightening each connection in with silicon tape. I can only imagine the leak will be worse when the car is actually running. I'm not sure the current leak would create a no-start condition, however.
4. Injection timing--good, set to 0.75mm as per greenbook 1985- models
5. Pre-heating system--need to check individual glow plugs but intimidated by #6 plug hiding behind pump.
6. Cold start device--unknown, anyway would this be a factor in warmer ambient temps?
7. Injection pump defective--bloody well hope not
8. Fuel filter, blocked--going to replace tomorrow
9. Fuel lines, blocked--unknown
10. Injectors defective--unknown
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  #10  
Old 08-08-2016, 07:31 PM
S&W 629 S&W 629 is offline
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A few months back I had a rather significant leak from where the high pressure fuel lines screw into the injector pump. The car ran well but fuel was leaking down the side of the engine block. Tightened the lines and stopped the leak. My point here is as significant as my leakage was it did not keep the car from running well, so I doubt that your starting problem lies there.
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