i just put a so pump on my pickup which was a ho before. it was a direct swap and i did it because the so pump gives more overall horse than the ho pump. heard it even matches the hot rod pumps. i didn't do hot rod cuz it was sposed to start and idle like crap. well this so pump idles like total crap. idles higher and has a little miss to it. when you work it a litttle (as in not just drivin around town) it really misses. doesent good at all...did i get a bad pump or what?

 

oh not to mention that it has very low power and it gets bad mileage. ive been gettin like 10.8

 

Could the problem be messed up timing? I haven't done a pump install yet, so I'm not sure how easy it would be to accidentally retard the timing when doing an install.

Regardless, it's certainly worth a call to the shop you bought the pump from and ask their input. I wouldn't throw a bunch of accusations at them about a defective pump, just describe what's happening and see what recommendations they may have.

 

I sweated about getting that key lined up in the keyway so much I could'nt sleep. When I got it in there I did a little dance in the driveway.

 

You gotta have a good performance upgrades to make it work out right. I did the same thing not knowing that it would have really low power without any real mods.

 

its really impossible to mess the timin up since the pump does it by itself. as long as you line the key way up its fine. 24v83, so with my box hooked up and some bigger injectors it will have what i want? cuz if not im gonna send it back and buy a hot rod

 

from what I have read in the past cause I will be going to a so when this one dies. is a SO on a HO pump will have a stumble at lower RPM's regardless of injectors or box. some have heard the pump just runs like poo untill 1600ish rpms. some have heard they did the swap and love it. you could mess with your box and lower the timing down and see if that makes any diff or helps smooth out. does your truck smooth out after a certain rpm ? how about smoke? is there alot getting dumped on low rpm? man I hope you get it balanced out I would like to go with a SO down the road.
also do you know anyone that would have a 2nd gen smarty to try out and see if that helps at all.

 

well my box aint hooked up but even it is i can't mess with timing, its just a straight fuel box. well when you are actually drivin it it runs pretty good. like you said it don't have much till it gets to about 1800rpm. then it doesnt do to bad. no it don't smoke much at all. i had a superchip max microtuner on before and it used to make it smoke quite a bit. didnt get much power out of it but it made it smoke good. anyways i didn't take it off when i changed pumps cuz i didnt figure it would matter but it hardly smokes at all now. and about the idle when you fire it up it runs about in the right spot as my ho pump did but once it gets warmed up and goes the notch on the tach right below 1000. but what bothers me is when i come to a stop sign it goes up to about 1000rpm until i come to a complete stop. then it has a really erratic idle like its skippin or something

 

I did a swap last year. The first thing that I noticed was a lot less off the bottom end but the power was smoother and better on the top end. I gained almost 35hp by swapping pumps on the dyno. Did you use the correct timing key for the SO pump. When I got my pump the timing key wasn't with it and I used my old key. Problem was it wasn't getting enough timing even with my EDGE and SMARTY adding timing. Changed the key out and its a lot better. I run MACH 7s and a HOT EDGE Juice as a daily driver. I am going to be selling my MACH 7s and getting some custom made 300hp+ injectors and a 64/71-14 for my twins and a second stage of NOS to hopefully see some big number and set a VP 6 speed record. Good luck and you might just want to get a bigger box to help on the bottom end a little better. Chris

 

You may have a bad pump. I have had mine swapped out for a few years now, and while it does have a very slight miss at idle and much less low end grunt compared to the HO pump; it more than makes up for it with the high end power and much less smoke running around town than I used to have with the HO pump. I hope you get your issues resolved...

 

After I swapped to HO the only thing I noticed was a variation in idle noise. I swear these things are like a random guessing game what you'll get from one truck to another. Mine doesn't even sound or feel like my buddies truck with the same pump and very similar mods. So .. good luck

 

pump had the keyway in it. thats what i really miss is the low end grunt it used to have. what about mileage? im gettin terrible mileage with it...im lookin at gettin some bigger injectors and hookin my box back up...but i dont wanna hook my box up if the pump is bad cuz it will void my warranty.

 

oh and if it makes up for it in the high end power does it smoke more in the lower rpms than the ho pump? i don't mind a little smoke but i really don't want a coal powered train either

 

where did you get your pump. I know alot of shops that sell their pumps and warranty them for one year even with a wire tap. but before you get to deep may want to just take it back tell them its bad get another and see if its the same, if its a better replacement then use that one and start adding bigger sticks and put the box on. maybe get a smarty or try one if someone has it by you to try out higher timing. good luck

 

From my experience, switching to an HO pump to an SO pump the loss in low end power meant that running the Edge untapped gave the same power as the HO did without any electronics. I have much less smoke in the low end than I did with the HO pump, and mileage has not suffered one bit in my case. I actually went from Mach 4's to Mach 7's when I installed the SO pump, and mileage dropped less than 1/2 MPG compared to the HO pump with the 4's; and I still have less smoke than before...

I would hesitate to recommend tapping the wire as there may be something wrong with your pump if mileage is that far off. Could you try hooking up your box without tapping the wire and see if there is any improvement?