Time for some thinking caps.....

[Morphious]

First off, I have to say not having internet at my new apartment sucks... . The cable guys can't get there till next week.



Here is a list of problems as I have noticed them, and am looking for input on where to troubleshoot... .



First, my max boost has fallen off. I used to be able to hit 34+ lbs of boost with my truck. It has a DD version of the Edge EZ and DDIII's. While at Muncie, doing the time trials sunday, I was able to hammer it pretty hard in the quarter mile to do some more diagnosis, the truck just plain felt flat. No power on the topend at all and the best 1/4 time I could get out of the truck was a 17. 50 and 83mph, I know the truck is capable of more. As some of you know, I am running a mallory 4150 fuel pump as my fueling source and have a mechanical guage (pre-filter). On my way home from Muncie, the guage started this bouncing bit, and I assumed like in previous instances that the brushes were worn out and it was time to replace them.



I replaced the brushes last night, still the same problem. I have the pump wired to a relay which I activate via a toggle switch inside the cab. If I turn the pump on and let it run, it holds a steady 15lbs of pressure, once I start the truck up, the guage immmediately starts this back and forth pulsing bit. The wierd thing is, the more fuel I am feeding to the engine, the less violent the pulsing is. The pulsing is very harsh at idle.



I replace the Fuel filter every 10k miles and do not believe this to be the problem, but will be replacing it as soon as I can pick on up at the part store.



Time for some conjecture: I think I may be having a problem with my injection pump, but have not seen anyone report a similar problem. The truck runs and idles like normal, I have always had a little bit of a stumble in the truck, even when it was completely stock. It doesn't die on top end, but I get no where near the smoke that I used to achieve either. I have checked all intercooler boots and everything else that I can think of. My guage lines for both the Fuel and Boost are Aeroquip stainless steel lines all the way to the guages, so I don't believe these are the problems either.



Any help on this would be much appreciated and sorry for the long post, hope it is readable.



Morph

 

[Lsfarm]

Bad connection

I would check out the pump wire connection, the average 'scotchlock' can't stand up to the heat and vibration in the engine compartment.



Go with the really trick pump cover connection, pretty much seals the connection between your box and the pump.



Hope this helps, and it isn't the VP44!



Greg L

 

[Morphious]

which connection are you talking about? I don't have the type of box that taps the injection pump line. The Fuel pump connectins are good as I redid the connections last night when I put the new brushes in (kit comes with new wires). I will recheck the plug for the box on the map sensor and where it connects to the service port, but those are stock connection fittings.

 

[Lsfarm]

Any Fueling or Timing box connections

Hi Morph, I thought you had a pierced pump wire type of box, that is what I was refering to with the 'scotchlock' comment.



But even so, some guys have had problems with the factory plugs not making good connections. One guy fixed his problems with just cleaning the connections and using dielectric grease on the plug connections.



Give this a try, it doesn't cost anything, just some time.



Hope this helps Greg L

 

[Morphious]

Next round: I completely unhooked the wire from the EZ that plugs into the service port. I noticed that the bouncing was a little less, but still there. One of the other things that I noticed, was that now I am able to get up to 30lbs of boost with it unplugged. I think one of my problems is my EZ is bad. The truck runs damned near as strong with it unplugged as it did with it plugged in, spoolup takes a fraction longer than with it plugged in. Thinking back, spoolup with the box plugged in isn't what it was like when I first plugged it in a little over a year ago.



This weekend, I will get a complete rebuild kit for the lower part of the pump and put new seals in the bottom part of the pump and see if that helps any.



Any other conjecture would be appreciated.



Morph.