No I am not kidding. I pulled the pump today to replace the oring on the back side of it. Yes, that was the problem, thanks to all who helped me. I removed the AFC housing and there was a plastic bottle cap there. You know, like one you would get off of a Coke bottle. It was cutdown to about half its height. I looked throught the sticky to see if there was supposed to be a spring there, but I saw no mention of one.

I was also suprised to find a ground fuel pin, already in there. Only issue I have with that, is the fact that at its thinnest part, it has a tiny crack. Its not all the way through yet, but I saw it. I have another pin, from PDR, bit it only has the tiniest spot ground on it. The one that is in there is massive.

Back on topic.

Why would the cap be there? Is it some kind of lazy mans valet switch? If the diaphram cant move up, the fueling level would never increase, right? Any ideas are welcome.


BTW...... I didn't have a wrench to get to the rear IP nut, so I cut the box end off of a wrench and left it about one inch long overall. I put it on the nut, put a chisel on it and hit it with a hammer. I wont be able to tighten it that way, lol, but I got it off. I may be able to pry on it to tighten it, but I hope to have a correct wrench tomorrow.

Sorry for jumping around.

 

under the afc cap and above the diaphram means it is full fuel all the time

 

Then I have problems, because my truck is a dog. I was hoping to get some more power out of it. I barely smokes as it is, even under full throttle. I was told, by the PO, that the pump had been tweaked, but he didn't know how. I was going to do a bunch of adjustments to it, but after seeing some other odd things, I don't know where to start. I wish I could set it all back to square one. I am now nervous about adjusting anything else because I don't know how far from original it is.

 

I think hacked would be a more accurate word to use.

Is there a spring in there under the diaphram? If there isn't there should be.

 

leper, to an extent you are still very limited in an intercooled truck by the size of the stock injectors... they are very small. Look at the full power screw, if the lock collar is still on that chances are, they didn't get much more than a turn or turn and a half. as far as barely smoking, you aren't gonna get much with those injectors... usually a puff on startup and a puff when you floor it from a stop, other than that don't expect much more than a have that can only be seen in the headlights of other drivers at night.

 

Under the diaphram, yes.

Lock collar, no.

I have a 366 spring to put in. I figured I might as well do it because the pump is so accessable.
My sadness comes from the fact that I expected to get a real power increase, like others have talked about. It is hard to believe that my truck is so weak, power wise, and has already been modified. With a ground fuel pin and the cap keeping it at full fuel and the power screw already turned, I now have to spend some real cash to get any more out of it. I bought a first gen so that I wouldn't have to do that.
I spent alot of money to get the truck reliable. Gauges, coolers, manifold, 16cm, and wiring. I did all of this before I started messing with horsepower, for reliability. I get 16-16.5 mpg empty now. If I put bigger injectors, I figure that number will go down.
I was hoping to get more power and not alot of smoke. Doesn't look like that is going to happen unless I spend several hundred dollars....that I don't have.

Kinda bums me out.

 

Don't be bummed! You're still driving a cummins. That's just cool no matter how you cut it!

 

Fuel pin is only worth 20 horse. I dont even have mine ground. I would get your afc setup working proper. Im sure theres pics up in the sticky what its supposed to look like. The afc just meters the fuel while boost is coming on. The full power screw is the one that makes the difference. Take the collar off that, turn that in a couple 3 turns, turn down the idle, and wait for the boost.

 

Thats all been done already.

Mabey I will get better mileage with the fuel pin moving.

 

Its actually an old-timers trick I have heard. Hacked is a better term

 

Hey Leper, I think I remember you posting in the thread about my boost leak that you were having the same symtoms. have you ruled out a leak somewhere? The difference was night & day in power once I found the leak and my mileage went back into the lower 20's MPH. I live a couple hours away - let me know if I can help.

 

Not sure if you've covered this in another thread, but what are your boost an pyro numbers under full load? All VE's are different and that is the only hard fact about these pumps. Having said that, a maxed pump with stock IC injectors should still be a pretty fun truck to drive...and should lay a decent cloud of smoke untill the turbo lights. You 'should' be seeing close to 1000 degrees and 22-24psi at full load, give or take. Before you spend $$ on injectors, I would look at fuel supply. Start simple with a fresh filter if it isnt' already and invest in a FP gauge. Even a temporary setup on the clean side of the filter will give you an idea where you're at. Low inlet pressure at the injection pump can cause the internal timing of the VE to not advance with RPM's and, among other symptoms, can cause low power and poor fuel economy. Keep you head up and start simple when looking for the low power culprit.
greg

 

Well put, Greg. I was going to say the same thing.

One more thing- check the guide pin in the AFC "well." WHen you cycle the throttle lever, you should see the guide pin pop out. You removed this to replace the o-ring. I have seen them bind up in the minimum position more than once.

ANother option is the advance piston sticking or being worn to where it doesnt move like it should. It will affect the MPGs more than one might think.

You're in good company with your horrible MPGs- I went to Memphis this weekend, and got 16mpg. I'm about ready to sell it based on the fuel economy (or lack thereof) alone. G/F's Dakota does mucho better than this one. Last truck outdid hers, at least in town. Hwy was about the same (22mpg) and I had 4.10s.

Daniel

 

You should have more power in that truck. My truck is the same as yours and can peg the pyro. The only thing I have is Dennyt's pin. I thought my pump was maxed until Dennyt started poking around under the hood. He got almost five more turns out of the full power screw. It is very fun to drive for an almost stock truck. It will definately let the smoke fly if I want it to.

 

I beg to differ on this one. The way mine is set up I can gain almost 100hp with my valet switch. Yeah I know I have a 14mm pump, but I know you can get more than 20hp, but there are a lot of variables that go along with that.

I know that someone mentioned to check the fuel pressure which would tell you if your supply pump might be going out. When my pickup was mostly stock I started loosing power and lost about 10#’s of boost it was my supply pump. I put a new one on and it made all the difference in the world.

Stomp