Pump help!!!
 

Ok... at the risk of sounding like a total moron, I need some help.

My truck was running very well before I installed the governor spring and advanced the timing 12-14*. I got everything put back together and now I can't get the truck to make any power. The truck burns absolutely clean, no smoke whatsoever (which is kind of nice, minus the lack of power). I can only manage about 18-20lbs of boost at full throttle, in second gear only, every other gear is maxed at about 10 lbs. My EGTs are as cold as the ice age (floored up a hill I can MAYBE get it to hit 1,000*). Lift pump shows 15+psi at almost all times...


Truck is a 90, non-ic injectors, M&H M4 fuel pin, HE351VGT, 4" turbo back, custom IC, IC pipes, etc etc...

Now, after I got the pump back together, I backed out the full power screw for safety, put the idle screw back to where it should be, and the truck tried running away (surprised, since I backed the full power screw so far out). I backed the screw out more til it would not start, then turned it in a little at a time til it would start and idle. It idled high, so I backed out the idle screw (ended up backing it out all the way, which I understand is fine).

BUT, we had the issue that the truck would idle, but I would hit the throttle and the truck would die. Turns out we put the throttle lever/cam in the wrong position which was leaving some slack in the governor (yes, I forgot to mark where it was when I took it off... like an idiot). So, to remedy this, we found where the throttle would start to put a little tension on the governor spring and clocked the throttle cam to that position (so, we turned that splined shaft 90* CCW). Started the truck up, and she ran away. Backed the full power screw out and got her to idle well again, and we had throttle control.

Kept playing with the full power screw trying to get some power and it would either run away or die, all within less than 1/4 turn of the screw. We can't get ANY smoke out of it, even if she is running away (so probably not a true run away situation, but IDK what else to call it). The only way I could even get a hint of smoke is if I turned the smoke screw in all the way (so that the lock nut could not even thread on it). Starwheel is one turn from bottoming out.

The fuel pin does seem like it might be sticking, so I am going to look into this today a little more, but I still feel like I should be able to get SOMETHING out of the pump besides runaway and not running at all. The fuel metering pin does pop out when I move the throttle, so that seems fine.

I know this is a long post with a lot of information, but does anyone have any other ideas? Do I need to clock the throttle lever/cam more? I'm about out of ideas without taking it all apart and retracing my steps...

Thanks in advance gents!
MK

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According to this, I have the throttle lever in the wrong position... hope that's right and I didn't take out the IP!

Sounds to me like your throttle lever is still indexed off. Everything working correctly, the only adjustment you would have to make would be the idle screw because it is a stiffer spring. Your fuel screw should go back to where you had it. I've read this situation several times. Just a mater of finding the right spot on the lever.

I do believe you're correct. I finally found some threads on it (unfortunately after I wrote this...) and it seems I am one line off from where it should be indexed. Going to switch that up here in a few minutes and see what happens.

Thanks for the advice! :rocking:

Normally I don't recommend changing the governor spring because it is such a PITA and you can accomplish about the same by correcting the throttle linkage travel. From the looks of your signature however, your up to no good.

I guess you could say I am up to no good. My goal is a fairly clean burning powerful truck, hence the VGT turbo. I re-indexed the throttle lever and had wonderful results, she moves on her own accord and everything. It's amazing what 1/16th of a turn can do!

Right now I am having trouble getting the full power screw turned up without high idling... so I guess I am pretty much where the pump stops, for now (til I can figure something out). She was cruising down the interstate at 20lbs and 1000* at 70mph earlier, I would like to cool it down a bit, so I may need to figure out how to get it to cruise with the VGT vanes open more... I also want to figure out how to implement the exhaust brake once more, and I am having a trans issue (hopefully just a linkage).

Not too shabby for being parked nearly 3.5 years.

Well, the way to get your idle down after turning in the fuel screw is to back out the idle screw. But, if your is already backed out you will need to modify the lever. The option is to re-index the lever, but you will loose an equal amount of full throttle travel. Nice catch 22 eh.
Opening up the the exhaust vanes will lower your EGT. There have been different attempts made on controlling the VGT mechanically, I don't know how successful they were. A push/pull cable would be a simple way to control it.
Still running the stock injectors?