FiTech Frustration! Fuel pressure takes a dive once hot

[MultiBeast]

Just curious if this new summit pump is providing too much pressure

 

[Broncobowsher]

Pumps don't create pressure, they create flow. Restrictions to the flow create the pressure. For an EFI with a bypass style regulator it is the regulator that creates the pressure.

 

[MultiBeast]

So I have a pressure gauge right before going into fitech with the “bad” fitech pump it would read ~50-60psi. Then give it throttle and it would almost drop to zero. New pump reads a constant ~90psi.

 

[MultiBeast]

Ok about to start throwing things. So I swapped in the new pressure regulator and fuel pressure went right to ~60 and help consistent. It also ran like it was supposed to. Then once it gets up to temperature it starts running horrible again and now fuel pressure is back at 100psi. So it looks like it popped the new regulator as well. What the hell? I don’t know what to do now. I’m going to post a video of what’s going on.

 

[markw]

How is your wiring between the ECU and fuel pump? Should be on demand. Working on this issue on our project right now. Feeling your frustration. Personally a carb is looking really good right now.

 

[MultiBeast]

Orange wire runs straight to fuel pump. Oh man a carb sounds awesome right now! I’m assuming the summit pump is pumping too hard and popping the regulator. Wondering if a separate regulator is a good option. This me absolutely livid right now

 

[bseager]

Not sure if it will help but you can adjust duty cycle to the pump in the handheld settings. I'm running the FiTech FCC at 70% (I think) and I haven't had any of the pump over heating issues even in the TX summer heat.

Sent from my SM-G892A using Tapatalk

 

[DirtDonk]

That sounds like an interesting setting bseager. Were you having any trouble before you did that, to compare to? Or did you set that right at the get-go and have been running that way ever since?

And MultiBeast, I'm having a hard time imagining that a fuel pump is harming the regulators. All the pumps compatible with these things are capable of at least 90psi and many go to 110-120 psi, in addition to some flowing much greater volume.
If anything, the regulators are "defective" rather than the pump pushing too hard.
Unless the pumps are able to push way more than that when hot, I just don't see it.

At least that's my thinking. I could be wrong, but it makes more sense to me.

Paul

 

[markw]

I've been trying to get some help from Fitech. No response to email and 20 min on hold this morning before I gave up. I don't have time to sit on hold for an hour. Seriously, I have an intake and square bore adaptor and a new Q-jet on the shelf. Very seriously considering the swap. I'll double check our wiring too. Don't throw anything, that usually doesn't end well.....

 

[MultiBeast]

Hahah. So it’s definitely the pressure regulator. When I put in the new one, the pressure read 60 pounds. It ran strong until it got up to temp, then it starts running horribly and fuel pressure is back at 100 pounds. I will get a video up by Wednesday and link it here.

The guy that is helping me with this whole process is mustang “tuner” and has done several sniper installs and he’s suggesting an adjustable regulator. Something like this
https://www.amazon.com/Universal-Ad...ulator+kit&dpPl=1&dpID=51Bh3Qzv66L&ref=plSrch

I have no clue what is causing the regulators to fail but I do not want to keep putting em in until I do... thanks guys!!!

 

[Broncobowsher]

I would consider doing the 58½PSI regulator/filter (GM LS filter) and just cap the return on the FiTech. No more FiTech regulator, stuck open or closed it won't matter if it is capped.

 

[markw]

Very cool! You have an answer!

 

[MultiBeast]

Quick question you guys do have a vac line running from back of fitech to regulator nip right?

 

[MultiBeast]

So to recap. I put this fitech on in August and had it running just fine using the fitech inline pump. One day I had it sitting, idling in my driveway and it stumbled a little then came back to idling. Then it did it again and completely stalled. After that it would run fine until it got warmed up then it would almost stall out when you are in gear and give it throttle. Figured out that the fuel pressure plummets when throttle applied. The fitech pump made a noise I’d never heard from a fuel pump from day 1, I already thought it was bad. A call to fitech confirmed this.
So I purchase new pump from summit. The one recommended in this thread. Put it on and immediately get fuel pressure back, but then the pressure goes to 90+ pounds. Ok, so the regulator on the fitech is bad?? I replace it with the correct Bosch part and pressure again goes back to the 55-60 range on my gauge.... for about ten minutes. Then it’s back at 90+ pounds. So the new pump is blowing the regulator it seems.
Which brings us to where I am now.
I’ve put an external Aeromotive regulator on it and capped the fitech return. It holds a solid 58psi now no matter what. I’ve also reset the unit.
But it still runs like shit once up to temp and in gear. It idles and revs just fine in neutral. At this point I’m wondering if the injectors were damaged??? Also going to pull my filters and check those. I’m so @&$:/!! Pissed about this. I was supposed to be taking it on a trip this coming weekend, doesn’t look like that’s going to happen.
I have not forgot the video. I will get that up ASAP. thanks guys

 

[BRONCO26]

Just a thought the EMC part of the FiTech could be going bad. It takes heat to make it start acting up I’ve seen it on a lot of cars that I’ve worked on at my shop. Just a thought

 

[Hazegray]

Are you sure it's the FiTech and not something ignition related? I've heard of ignition coils working up to the point of heating up, then crapping out....

 

[markw]

I finally pulled mine off to send back to Fitech. Tried everything we could think of. Waiting for an RMA # to ship. Almost pulled the trigger on a Holley Sniper last night.......

 

[73azbronco]

I'd throw a carb on it and make sure it was not ignition related.

 

[Attac]

I finally pulled mine off to send back to Fitech. Tried everything we could think of. Waiting for an RMA # to ship. Almost pulled the trigger on a Holley Sniper last night.......

Do it Mark
You will not be dissapointed
I am still waiting on a RMA from Fitech 10 months later............
Chuck

 

[BroncoJAK]

Do it Mark
You will not be dissapointed
I am still waiting on a RMA from Fitech 10 months later............
Chuck

I had to get Summit involved to get the RMA number sent.