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Author Topic: Combusting too early?  (Read 1181 times)

December 16, 2017, 03:08:26 pm

Scrambles118

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Combusting too early?
« on: December 16, 2017, 03:08:26 pm »
It would seem my sweet angel of combustion is acting up.

A fresh pump rebuild on an 87(?) TD.

So I performed a swap into my 81 caddy with a mechanical injection TD out of an unknown year, i suspect late 80s.  I can get the engine to run on silicone spray but only at an idle (way better than starting fluid for obvious reasons.) That tells me my crank to cam timing is right.  But after setting the timing using the proper tools a couple times I keep getting the same result.   During cranking you can watch the engine try to start backwards with the injection pump connected.  The engine turns in the wrong direction for a split second, kicks the starter gear out and then continues to crank then trys to start backwards kicks the starter out and so on. 

My assumption is that it is combusting too early but I dont know why or how to solve the issue.  Wrong glow plugs, improper pump timing

Ive tried loosening the pump bolts enough to rotate the pump by hand given it has slotted bolt holes and it does seem to help in one direction or rather the symptoms arent as bad.  I set the pump using the pin with the engine at TDC with the correct pin locked in place.  So it doesnt make alot off sense to me what is going on.  If somehow gas made it into the tank, would this be a symptom?  (i dont suspect gas did but since it wont run on its current fuel supply)  I may remove the fuel line to the pump and run it out of a can of diesel today to see what happens.  Thats my best guess towards what to do next.  Ive searched and searched with no one else seeming to have run into this before.  What do you guys think?



Reply #1December 16, 2017, 06:15:11 pm

Scrambles118

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Re: Combusting too early?
« Reply #1 on: December 16, 2017, 06:15:11 pm »
answered my own question, appears to be air in the pump and everytime it would hit an injector it would naturally roll the engine backwards

so the 1.6 TD swap is successful
IT LIVES! My sweet angel of combustion!

Reply #2December 16, 2017, 08:03:49 pm

ORCoaster

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Re: Combusting too early?
« Reply #2 on: December 16, 2017, 08:03:49 pm »
So did running it off a bottle get the air to clear out and then it ran OK? 

How did you actually fix the problem?  Just keep trying to start it until the pump filled with diesel?

Just curious. 
Now Own 1981 Caddy as the NEW DISTRACTION to all that is around me.  Project Away!

Reply #3December 17, 2017, 04:44:16 pm

Scrambles118

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Re: Combusting too early?
« Reply #3 on: December 17, 2017, 04:44:16 pm »
Filled the fuel filter with transmission fluid so i could watch movement in the fuel line.  Still getting air from somewhere but I ran into yet another problem with this swap ill dig into later.  My exhaust doesnt line up with the turbo manifold.

The fix was like the manual says, just break the fuel lines loose at the engine, crank the engine without using the glow plugs and tighten the fittings when fuel starts to come out.

alternatively you can crank using the glow plugs and silicone spray to make the engine start and prime much faster. 

Reply #4December 17, 2017, 07:53:01 pm

ORCoaster

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Re: Combusting too early?
« Reply #4 on: December 17, 2017, 07:53:01 pm »
OH Yeah, the problems never really end do they.  Just go away or can be ignored for a week or two.  Then they just need attention to fix.  By then you have thought about it enough that it is easily done.  And at that point you wonder why you didn't do it weeks ago.  Frustration impedes solutions.
Now Own 1981 Caddy as the NEW DISTRACTION to all that is around me.  Project Away!

 

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