jpavao1066 Posted December 18, 2016 Share Posted December 18, 2016 Hi everyone, I have a question on the injection pump in my '66 r600. The engine is a 673C, and since I have put the truck on the road, it always seemed like it was a little underpowered. I know it is not going to break any land speed records by any means, but it feels to me like it is a little under fueled, especially on the low end. I have tried adjusting the pump for more rack travel from information I have heard and seen from other folks (since this is the first pump of this style I have done any adjustments too). But the adjustments do not seem to make any difference. The fuel filters are brand new, and all of the lines to and from the pump are all brand new as well. I have also noticed that no matter what I have done, the truck has almost virtually no black smoke, even of it is lugged down or if you plant the accelerator. I have never seen an old diesel that didnt smoke even a little, and with a little pump adjustment there should be something there, but I am not able to make a noticeable difference. Also to be clear, I am not a hot rodder looking to crank the pump to the moon and over fuel the heck out of the truck, and I am fairly knowledgeable with different fuel injection systems so I dont want you guys to think I am poking blindly at the pump looking to ruin it or anything. I am just having a hard time figuring out what my problem may be, and if any of you may be more familiar with these pumps that might have a thought or an idea as to what I could check next. Thank you in advance! Quote Link to comment https://www.bigmacktrucks.com/topic/48065-pump-question-on-673c/ Share on other sites More sharing options...
theakerstwo Posted December 18, 2016 Share Posted December 18, 2016 (edited) It has been 45 years since i have worked on those pumpsn but if i remenber right you have to remove the pump and take the front housing off of the pump housing.Then on the front end of the rack was a screw screwed in to the end of the rack with shims under it.This was to keep drivers from getting under the governor cover and setting the rack out for more fuel.Way it worked was it would limit the travel of the rack by the screw hitting the housing even if you set the rack out in the governor.If i have it wrong let some of the old timers tell you.We would take the screw out of the end of the rack and toss it.If it was not this pump it was one older than this but i think this is same thing.If you would post a photo it would help.The pump i am talking about will havea alumin cylinder looking thing with a screw in the middle on the front of the pump housing.The screw was were we would remove and put a depth mic in to measure the rack extension. Edited December 18, 2016 by theakerstwo Quote glenn akers Link to comment https://www.bigmacktrucks.com/topic/48065-pump-question-on-673c/#findComment-355429 Share on other sites More sharing options...
6v71 Posted December 18, 2016 Share Posted December 18, 2016 Is this what your talking about? This is out of a 1966 B61T service manual. Bosh APE 6BB type pump. Quote Link to comment https://www.bigmacktrucks.com/topic/48065-pump-question-on-673c/#findComment-355461 Share on other sites More sharing options...
theakerstwo Posted December 18, 2016 Share Posted December 18, 2016 Right there it is.Dont matter how much you set the rack extension out the rack will move only so for untill you take that tamper pruff screw out. Quote glenn akers Link to comment https://www.bigmacktrucks.com/topic/48065-pump-question-on-673c/#findComment-355466 Share on other sites More sharing options...
jpavao1066 Posted December 18, 2016 Author Share Posted December 18, 2016 Thank you guys this makes a lot more sense now! When I went back and looked at the governor adjustment on the rack travel, the rack linkage's stop plate was not even hitting the threaded rod with the two lock nuts that adjusts the max rack travel, so it must be the rack screw you guys are talking about keeping it held back. I will readjust the governor adjustment so I have a reference to start from before I remove the screw and then give it another try. I will also try to get a pic of the pump posted up. Just for clarification, the injection pump must be completely removed from the timing case to access the rack screw, right? Thanks again guys for all of the info, this is a huge help! Quote Link to comment https://www.bigmacktrucks.com/topic/48065-pump-question-on-673c/#findComment-355479 Share on other sites More sharing options...
Hobert62 Posted December 18, 2016 Share Posted December 18, 2016 Keep the good info coming. I'm following this too. Mine being a contour cab b67 was probably a city truck for some freight company. I also adjusted the lock nuts and noticed very little difference. I'm guessing this my be whats going on to mine also. Quote Link to comment https://www.bigmacktrucks.com/topic/48065-pump-question-on-673c/#findComment-355483 Share on other sites More sharing options...
theakerstwo Posted December 18, 2016 Share Posted December 18, 2016 Yes the pump has to come off and also the pump to engine timing is very importan so do it as the manual says instead of just bolting it back on.I know you can get it to run by just bolting it back on but you can be off as nuch as maybe 8 degress and that could be too much. Quote glenn akers Link to comment https://www.bigmacktrucks.com/topic/48065-pump-question-on-673c/#findComment-355486 Share on other sites More sharing options...
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