Big Oil and Big fuel not so big..

Rideracelivemx7 · Jul 18, 2013

Hey guys im not sure if i'm over reacting here but let me try and explain whats going on.

So back in late April I purchased some goodies for my truck as I pulled the motor to clean and add some power. (It was just fine before)
I sent my injectors in to be built to 350/200s(from the old 250/100s) by Cass .
I had a set of low mile heads redone, decked, valve job and clean up blah blah. Cross over tube, melling lpop and a few other small things.
When I got the truck together and running it idled ok but when driving it seemed to buck. after a series of reburns we decided I just didn't have the oil(t500) to fine tune the truck.

Fast forward 2 months later I have a set of twin terminators installed as of last night and to be honest I notice zero difference between how it ran before and how it runs now. It starts a little faster now but it doesn't accel any faster, doesn't seem to have more power or pull harder. It doesn't seem to smoke as much as I thought it would with this size injector either.

With these hpops installed shouldn't I notice a difference right off the bat? hell my old tunes drive the exact same in the pedal as well, its not any more responsive.

I have 2 tuners on the same chip and the truck has similar symptoms with both files, bucks and just doesn't seem to have the power that it should with this set up. Anyone have a single idea? I have 2 superduty pumps in series for fuel pumps plumed with stock lines on the block still, do they need to be bigger than the 5/16s or 3/8s that they are?

Gearhead · Jul 18, 2013

Series on the fuel pumps? Have you verified that you are maintaining fuel pressure at WOT?

Rideracelivemx7 · Jul 18, 2013

only other thing that I noticed is(even with a new IPR in the termys) my throttle pedal still does what I did even with the 250/100s and 5spd. If you hit the skinny anything past half throttle looses its sensitivity big time for the first 1/3 throttle until you flick the key back real quick to restart it. This is every time and I was hoping it was my IPR

Rideracelivemx7 · Jul 18, 2013

Matt that's my next step is to put a mechanical guage in the cab. and I ment in Parallel for the fuel pumps not series, my bad

strokin'_tatsch · Jul 18, 2013

Like I've been telling you for at least a year. You've got to get some diagnostic equipment if you ever plan to figure these things out. I would like to know what the ICP and fuel pressure is doing..

As far as the throttle pedal goes, have you tried replacing it with a known good pedal assembly? In other applications I have seen TPS voltage be fine at idle, but after cycling the TPS, the voltage starts jumping around a lot and drops off at idle causing slow throttle response and bucking under part throttle. I would check TPS voltage with the key on, engine off and then again with the key on, engine running. I've also seem them be fine with the engine off, then act stupid with the engine running. Again I've never seen it happen on these trucks, just other applications.

dirk0 · Jul 18, 2013

Agreed. Fuel and oil. You'll need new tunes and possibly live tuning to sharpen those injectors. The pw and pressure on the tunes for the old injectors are probably way off now.

And 2 pumps in series? One pushing the other??? They should be in parallel pulling from a 5/8 sump or pickup tube.

Rideracelivemx7 · Jul 18, 2013

They are in parallel sorry, I need to edit that. I have the correct tunes but what I ment by old ones is the tunes for the single pump vs the dual pumps. I'm going to be running a contribution test to rule out Injectors.
Hell I might just have the worst case of air ever. Drives me nuts though

Groomzybanshee · Jul 18, 2013

Check tps.

Ron's Power Stroke · Jul 18, 2013

do not put a mechanical gauge in the cab....if the hose lets loose or the gauge craps out you will have the smell of diesel in the cab for a very long time... use an electric gauge if you can swing the price... if not ..mount the mechanical gauge out on the cowl.. I did mine with a piece of 1-1/2" PVC for permanent use..but you can run a hose out to the cowl and tie the gauge down to the wiper just for testing...

dirk0 · Jul 18, 2013

Ron's Power Stroke said:
do not put a mechanical gauge in the cab....if the hose lets loose or the gauge craps out you will have the smell of diesel in the cab for a very long time... use an electric gauge if you can swing the price... if not ..mount the mechanical gauge out on the cowl.. I did mine with a piece of 1-1/2" PVC for permanent use..but you can run a hose out to the cowl and tie the gauge down to the wiper just for testing...

DiPricol had an electronic unit (good luck finding those now) and someone made a electronic unit.. Maybe ISS or Autometer.

Ron's Power Stroke · Jul 18, 2013

i know Autometer does..but there not cheap....

strokin'_tatsch · Jul 18, 2013

I run an Isspro electric fuel pressure gauge on one truck and an Autometer electric fuel pressure gauge on the other one. Both had sending unit failures within the first 500 miles, but after replacing both sending units that one time they have both been very reliable.

Ron's Power Stroke · Jul 18, 2013

some day ill get one for in the cab...right now i got spend time with my kid till he goes off to boot camp... then i can go to work on getting this motor in...he will be stationed in GA.. I'm hoping to take my truck to graduation and have her live tuned by some body... i wish gearhead was a little closer to there..

Rideracelivemx7 · Jul 18, 2013

i had glow shift elecric fuel pressure, zero luck with them.all my other gauges by them were flawless but the fuel pressure gauge and sending unit were replaced several times. would be fine for a week then peg out at 100.

Tom S · Jul 18, 2013

If it was mine I would be watching ICP, MAP and TPS on a scan tool for sure.

dirk0 · Jul 18, 2013

Rideracelivemx7 said:
i had glow shift elecric fuel pressure, zero luck with them.all my other gauges by them were flawless but the fuel pressure gauge and sending unit were replaced several times. would be fine for a week then peg out at 100.

I wouldn't ever use that brand. I've heard nothing but bad things about them.