Do Injection Pumps Advance as RPMS go up?

[84TD]

Like a gasser distributor? Just wondering.

Also I posted in the marketplace, I am looking for a rebuildable IP to play with and a factory air cleaner base if anybody has one laying around. I know I read on here somewhere that you can rebuild the IP. Mine is GTG but I want to rebuild one myself and see how hard it is to do. That way I could put it on my truck and keep mine for a spare or something. I wouldnt mind doing a write up on it too.

 

[Agnem]

Yes. Advance is governed by two things. At low RPM's, there is an external cam on the drivers side which pushes the advance piston in from outside the pump. At higher RPM's, fuel presure takes over and advance is maintained hydraulically internal to the pump. There was a group of us that discected an IP late one night at last years IDI Weekend.

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[84TD]

I remember now the other thing I was wondering. Can Fusible links be replaced with fuses? reason I ask is a while ago one smoked in my truck and I replaced it with a inline fuse of the same rating. I found 3 or 4 in the same area right there where the starter solinoid is. Is that all of them?

 

[Cheaper Jeeper]

.....Can Fusible links be replaced with fuses? reason I ask is a while ago one smoked in my truck and I replaced it with a inline fuse of the same rating.....

Well, obviously they can - you just said you did/b] !

If you mean to ask is it OK to replace them with fuses, the answer is yes. A fusable link is sort of a "slow blow" fuse. It will handle an over-current condition for a little longer than a standard fuse before burning out.

So replacing it with a regular fuse of the same rating still provides the same amount of protection - even a little more protection in the sense that the fuse will blow quicker.....

 

[Mr_Roboto]

The cam and lever actually RETARDS the timing. The internal advance is linear based on RPM, the external arm allows maximum timing under low loads (low throttle) and retards timing under heavy loads (high throttle).

Similar to the balance of centrigal advance and vacuum advance in a distributor. You have high vacuum under light loads, lower vacuum under heavy loads and timing is adjusted accordingly.

 

[84TD]

Well, obviously they can - you just said you did/b] !

If you mean to ask is it OK to replace them with fuses, the answer is yes. A fusable link is sort of a "slow blow" fuse. It will handle an over-current condition for a little longer than a standard fuse before burning out.

So replacing it with a regular fuse of the same rating still provides the same amount of protection - even a little more protection in the sense that the fuse will blow quicker.....

Cool, I have a birds nest for wiring, I am going to try to go through it and clean it up. I ordered new Stewart Warner boost and pyro so when I put them in ill try to do it all. I am going to add a few switches too. 1 to turn the power to my radio so if I am not listening to it, it will bee completly dark, 1 to enable disable my cold idle advance, 1 to enable disable my fast idle, 1 for my clearance lights, maybe 1 for a bed light and a few extras for later add ons. Before all that I am going to the bone yard this weekend to score an aux fuse box. Anything else to put a switch on??

 

[Diesel JD]

Yeah I had thought that the timing retards as you increase throttle, at least that's what mine did when we hooked the lumniosity probe from the MT254 to a timing light. At 1400RPM it was at 1.5ATDC and as you continued to advance the throttle the timing retarded a degree or so.

 

[Mr_Roboto]

Timing varies a lot, if you look at the cam it's a convoluted surface to advance and retard at different throttle positions.

 

[DieselRecon]

The injection pump advances the timing as the engine speed increases. Under light load the timing increases even further. Under heavy load the timing decreases till the RPM's come up to a desirable level. The lever on the side of the pump controls the amount of advance according to the throttle position. To much advance and the engine will rattle with a fuel knock of sorts which is not desirable in most cases.