[Formulajones]

I'm not familiar with Fitech, does it have extra inputs and outputs like Holley does?

My Sniper has extra inputs and outputs, so I run a transducer on the fuel line, go into the computer and tell it fuel pressure and check the necessary boxes etc.... so I can now read fuel pressure on the touch screen. Did the same with oil pressure.

The nice thing about that is that Holley now automatically will datalog those features once they are added so I don't have to try and stare at gauges on WOT runs, just datalog and go back and look at it. I've also set safety features along with the added data so if something is out of range it will alert me.

Might be something to look into in the future. Maybe someone more familiar with Fitech will chime in and explain if any of that is a possibility.

[HWYSTR455]

I think the upper FItech models might have logging, but all the base throttle body kits do not.

I know others who have FItech stuff that are adding systems for logging, some even are moving to MSD Grid.

Same people who discovered issues with the internal regulator completely bypass the internal one, going to an external, which allows for adjustments. The internal ones either fail out of box, or continue to fail in-use, regardless of how many they've replaced.

I think even FItech support at one point was advising to move to an external regulator, but that may have been in earlier models.


.

[JLMounce]

FiTech will log, but only its own sensors. You can’t log anything external with it. So no way for me to log fuel pressure unfortunately.

[65madgoat]

Has a new fuel pump been put in yet? I have seen fuel pumps working fine until heat builds up in it from (hot)return line gas and then you have issues like it appears you are having.

[JLMounce]

Had some time this afternoon to play around with the car after doing some work on it late last weekend and this week.

I replaced the fuel pump along with a complete rebuild, including new gaskets, internal return lines and wiring pigtails. Additionally I swapped out the coil for a known food Blaster 2 coil and reverified that the rotor phasing wasn't out. The lockout mechanism on this Summit Billet distributor has a small amount of play in it, but nothing that is creating an issue where the rotor paddle isn't directly under the cap terminal at loaded ignition advance.

I can't yet be 100% certain this has done the trick, but the car did perform much better. I can't yet go full throttle as I've reset the complete learn on the system and it needs some time to adapt to the changes.

Prior to this work I took the advice of Paul K as well as Steve C and did some troubleshooting on the ignition system itself. Idling and free reving in the dark, there is no arcing apparent in any of the plug wires or their boots, including the coil to cap wire. Without load on the engine, I was able to bring free revs up to above 5000 rpm and hold them there for over 5 seconds without a hint of a miss.

I do think that I had a failing fuel pump or a dying coil, possibly both. Considering the engine will rev all the way to 5000 rpm and beyond without load leads be to believer there is not a valvetrain related issue here, which I'm certainly thankful for. It appears to have only been load dependent.

For good measure I'm going to purchase a new set of plug wires as these ones were installed at the same time as the FiTech back in 2015. I'll grab a NIB Blaster 2 coil while I'm at it to keep as a spare.

I'll update again as I get some miles on the car, but hopefully this chapter is closed and I can enjoy the driving season!

[steve25]

Thumbs up, it sounds like you got.

[65madgoat]

Right on. I figured just a fuel pump was your main issue from the start. Dealt with same thing myself. I went to the new AC Delco (ZL1) non-return line in tank pump (can buy anywhere anytime) with a Vaporworx PWM and never looked back. Flawless set up. Ideal in my opinion.

[HWYSTR455]

SWEET!!! Think you got it!


.

[JLMounce]

It's been a while, but I wanted to bring this back up. As many of you that replied here know by now, I rebuilt this engine shortly after this thread completed.

I've had that engine back in the car since the middle of October and I've tried to put as much miles on it since, weather permitting. Recently as I've started to really "use" the engine spiritedly, I felt that the performance was somewhat lack-luster considering what the engine made on the dyno.

No popping, no surging and while there was not a loss of acceleration or struggling to make RPM, I just felt that the car was underwhelming for something that made close to 600 hp on the dyno. Far beyond what you'd expect to lose putting the engine in the car and hooking up a full exhaust.

So, I started hooking the laptop up to the various computers in the car to check on things. Commanded timing and observed timing is spot on, commanded and observed fueling also looked good. Without being able to prove out anything from the EFI, I turned my attention to the transmission controller. This is where things got interesting.

Below 50% throttle, the car runs/drive how you would assume. At that throttle input, the car is actually very quick, but beyond that there's just not much left in the tank. I did a couple multi-gear full throttle pulls and the logs were interesting.

Below that 50-60% throttle rate, the transmission is behaving as normal, with line pressures and shift points occuring very accurately to commanded points. However nearing 80%-100% throttle, things went wacky. The US Shift quick 4 uses some ballistics algorithms that are loaded agains RPM if the signal is available and input shaft speed. That algorithm creates a rising and falling engine speed analysis that has bearing on line pressure, gear selection and up/down shift operations. What I found was that my provided RPM signal was all over the place. It would at points beyond 3000 rpm spike to well over 8000 rpm, before falling back in line and spiking again. This was messing with the shift logic and causing early upshifts. In some cases, skipping 2nd and 3rd all together. The combination of that upshift to 4th and the amount of load carried by the torque converter was rendering that almost unnoticeable as it was happening while the converter is slipping quite a bit. There were points in the graph where calculated converter slippage was nearing 20%.

So, I spoke with Baumann Electronics about the issue and it ended up being a pretty easy fix. The installation kit comes with several resistors that need to be used in the RPM signal wire depending on what type of tach output you're using, in my case the negative coil which is as we've seen very dirty. This step appears to have been omitted by the shop that did the installation. I sourced a 47k ohm resistor, soldered it inline and immediately woke the car up. It doesn't short shift 1st any longer and you can hold gear as necessarily with throttle application as is intended by the ballistic algorithm built into the computer. The lack of performance I was feeling was the fact that the engine was trying to pull the car through 4th gear at speeds of only around 50-60 mph.

This does also go to show how important wiring is on these cars when you're using modern computer controlled equipment.

I also believe that the WOT backfire I was experiencing was related to a torn intake gasket that I discovered when I tore down the engine as it tried to spin a rod bearing. The gasket at the #6 hole had torn away and was blocking/being sucked into the intake port. I believe the gasket was soaking the fuel air charge, creating a rich condition (as observed from the spark plug) that was creating rich backfires, specifically in the exhaust. While all of the rod bearings in my engine showed signs of severe wear, the rod bearing that attempted to spin did correspond to cylinder #6. It makes me wonder how much this issue that cropped up contributed to the eventual failure of the engine?

Anyhow, clean bill of health now. Roads are dry but cold here in northern Colorado. Now that the transmission is acting properly, it's spin city. We'll see how big of a traction issue I have when the pavement warms up.

[65madgoat]

Glad you figured it out. I was hoping this would get you to finally put a much deserved stick in that car!! ;-)

[JLMounce]

Admittedly, at this point the money difference would have been minimal. The pedal carrier issues related to the 69 bird is still an issue, but nothing that can't be solved.

The new engine is at the top end of the service limits for a TKX, so we're in T56 magnum territory now.

[65madgoat]

...the TKX will suffice and could always get it cryo treated and REM polished. Sure they are rated to 600tq, but Tremec dealers will tell you that is conservative.