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Turn up the fuel pump

65K views 31 replies 14 participants last post by  Harry 
#1 ·
The diesel shop did some research and talked to a Yanmar mechanic. They backed out the fuel screw 1-1/2 turns from stock. The mechanic said that the Ranger accelerates a lot quicker now, and gained maybe 2 mph. He said that the injectors in this engine will never be able flow enough fuel to be able to overheat the engine, so it's pretty safe to turn up the fuel without hurting anything.

Now she rolls the coal. LOL.

 
#5 ·
Anything under 1500F is fine. Mine's not near that hot.
Turning up the fuel makes a big difference. It accelerates a lot quicker. The diesel mechanic raised the RPMs up to about 3800, by adjusting that thing that looks like a little fire hydrant, above the fuel plunger adjustment screw. He said up to 4000 is about the limit for this engine. It certainly does smoke if you push the pedal to the floor, but the Ranger hardly makes any smoke and goes almost as fast if you only press the pedal about 85% of the way. So if you just don't mash it to the floor then you don't have to worry about a big cloud of smoke. The mechanic had the fuel plunger set at 1-1/2 turns out from stock. On flat ground the speedometer got up to 42 mph. Previously my top speed on flat ground was about 39. I then backed down the screw to 1-1/4 and my top speed went down to about 40, so I think I'll turn it up to about 1 3/8 and see what happens. Even at 1- 1/4 turns it still has lots more acceleration than stock, but not as much top speed as 1 1/2 turns. Anyway, I'm happy with the results. The engine isn't much warmer than it was before, even after a long drive at top speed. But I did buy a nice Pyrometer that I'll install later. I want to do some air box modifications too.

 
#6 ·
I just turned mine up to 3/4 and man what a huge improvement. I get my k&n tomorrow so I'll get back with ya on that one. But after reading this post I'm gonna turn mine up some more. I read the ppe turbo kit directions and it said 1.5 turns out with there turbo kit so I figured 3/4 was plenty safe. But it'll be cranking out some more tomorrow
 
#9 ·
I'm sure they don't want to cover engine work when someone's had thier fingers in the pump ;D
With that said, if I had bought the diesel like I wish I had, I'd probably turn it up too.
 
#10 ·
As a previous diesel truck owner I just caution you to get your pyro installed ASAP. I don't know if this thing is turboed or not from the factory but you still don't want to melt anything past the cylinder head. 1500 degrees is the upper limit. i wouldnt go past 1300-1350 The way mechs catch extra fuel is to look for star scorch marks on top of the piston, other than that they will be clueless. Just turn your fuel back before service.
I'm all for unlocking power the factory left behind. It's hard to kill a diesel. The only other thing id look at is clutch upgrades. Awesome work bro. I love that diesel smoke!
 
#11 ·
Agreed. Alot of black smoke without any boost to go with it means quite hot EGTs.

As for not being able to kill a diesel, I don't know if that's completely true since alot of people that play with them have killed them!

This yanmar is no exception. Talking with PPE performance they told me that fueling this engine past their reccomended specs (with turbo) can cause these engines to throw a rod. They didn't say weather or not they had the first hand experience, but I assume they found out just how much the little engine could take the hard way.

If you figure that the factory engine made 24 hp, and if you get the reccomended 5-10 hp PPE claims, then you're talking about a 20-40% improvment in power. I don't know many engines that can make more power than that reliably.

As for clutch upgrades, I talked with Dale at DDP about half a year ago, and he was in the process of seeing if he could upgrade the clutch. the few times I called him back he still hadn't made any progress on it.
 
#25 ·
turning up pump

Ok so i figured out which screw to adjust the rpm it is the funny looking one on top.Where is the screw that they are talking about to turn up the fuel. Does anyone have any pictures of the pump showing which screw is which. I have a 2011 and would like more power.Any help would be great thanks
 
#26 ·
I put the k&n in mine. They don't list one for diesel but it's the same as the 800. Then I took off my stock exhaust ( don't know if you noticed that your diesel has a 2" inlet and a 3/4" outlet) anyway I cut the end off took out the guts and replaced all the small pipe with 1 3/4" then welded it all back together between that the k&n and turning the pump up it amazing the difference from stock. My dad has a 2012 ranger diesel single cab with stock tires mine is a diesel crew cab with 30" outlaws and I can smoke his a$$ in take off and full sprint. The downfall is I have broken 3 axles. So now upgrading to custom built units
 
#27 ·
hey WWT2
Ive got 2012 single cab diesel and looking for a bit more power too, when you say K&N thats an airfilter right i looked on their website and they have one for the diesel does it just replace the original one and let it breathe a bit better, how much did you turn your fuel pump up i was thinking just one turn to be safe after reading here, have you turned up the rpm like boggs was suggesting (are there two diferent ones)and also anyone got pics of the fuel and rpm screws i havnt had a good look yet. did you do all your mods at the same time, the exhaust probly has a fair bit to do with your performance do you think, i mite try this as well
 
#28 ·
Yeah the k&n is just a replacement air filter. Better air flow. I turned my pump up 1.5 turns and no problems other than axles. I have an egt gauge on mine and I have had it under hard load and only hit 1000 degrees so not to bad. If you look up the ppe turbo kit instructions it tells you and has pics of the the fuel screw. I haven't turned up the rpms. Yes the exhaust was Abigail help probably the single biggest but takes some fab skills
 
#31 ·
Hello,
I just purchased a 2012 Ranger crew diesel and would also like to turn up the fuel screw some but I can't seem to find any pics or open any of the links that shows me exactly which one it is.
Is it the screw that i'm pointing at in the pic, I understand I need to take of the tamper cover but it looks like this is more for adjusting where the throttle cable stops.
Thanks
 

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#32 ·
Yanmar Polaris

I am also looking for that adjustment .. that one you are pointing too is the high end throttle travel adjustment not the fuel adustment. I understand it is near rge fuel pump..I was hoping one of theses forum members could reply with a location and photo..
 
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