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Talk me into / out of a Fitech/holley sniper system

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How was the process of installing the dizzy.
does the clip after the rotation, seems awfully close to it.
Either way those numbers are impressive.
Does it also control the elec fan function or you have it set up differently
any pics of the fuel pump filter(s) instal
 
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Keep an eye on your IAC Steps through the learning process. If that gets out of range you’ll find it doesn’t run right.
 
MEMO43 said:
How was the process of installing the dizzy.
dies the clip after the rotation, seems awfully close to it.
Wither way those numbers are impressive.
Does it also control the elec fan function or you have it set up differently
any pics of the fuel pump filter(s) instal
Click to expand...

Distributor is just a normal GM HEI with a 6 position pickup instead of 8. Installs the same as any chevy engine. The clip does touch the distributor, but the Carb touched as well. The 4.3 had always ran the small cap computer distributors other than the very first year in limited applications. I should have put a small cap in but I didn't want to deal with an external coil. If end up using the ECU timing control the distributor will be a small cap.

The electric fan is controlled by the ECU. The ECU has a ground signal to hook up to a relay. I had just a simple temp switch installed before to control the fan. Replaced that with the ECU temp sensor.

My fuel system is my own stuff. I have a Walbro 255 in a fuel cell with a holley pump hanger that has an integrated pressure regulator. I just pulled out my low pressure one I had at 6 psi for my carb whit a 60 psi EFI regulator. Its a returnless system with -06 hose from the tank to engine. If I was doing a fuel system around the EFI I would have done a return system and used the regulator in the TBI unit. Cycling fuel helps with keeping the temp down. I have never had a problem with returnless before though so I am not worried about it.

No real updates though. Been out of town. I will try to drive it around today and get some tuning done.
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Okay my first update. I gave it a few heat cycles and lots of idle time in the driveway while I worked on other stuff. Fan and all of that jaz works like its supposed to. I was able to go drive it for a bit before the weather went to crap, maybe 30 miles or so. It really does seem like it picked up some power. It was a little wet out but it spun the rear tires fairly easily and carried it through the rpm range.

All around driveablity needs a bit of improvement. It runs great but has a few hiccups here and there that will clean up with turning/learning. Really need to richen up decel. It pops a bunch. There is a tiny stumble when getting back on throttle after decel, This is a common thing from what I read. Lastly I need to speed up the IAC. The throttle hangs a bit longer than I would like when I let off the gas. IMG_1397.jpeg
 
Awesome update, hopefully it tunes an learns itself.
are you still allowing for warm ups before.tou drive or has it been turn the key and go.
Is there any binding on the throttle cable
or enough tension on the return spring.
that might be the cause for the hang up when you let off the throttle
 
MEMO43 said:
Awesome update, hopefully it tunes an learns itself.
are you still allowing for warm ups before.tou drive or has it been turn the key and go.
Is there any binding on the throttle cable
or enough tension on the return spring.
that might be the cause for the hang up when you let off the throttle
Click to expand...

So far its been turn key and go, no need to warm it up.

Throttle cable is fine as TPS returns to zero%. The problem is in the tune. They use pretty conservative speed for the Idle motor control. Too low of a value and the idle takes forever to come down all the way. Too fast value and the idle surges up and down as the ECU over corrects for itself. Conservative is safer. I just need to go in and bump the speed up a bit.

I am not going to mess with any settings yet though. Ill give it 100 miles to learn a bit. Then Ill pull a log and check it out. Start changing things from there.
 
I’ve tried fi tech on a few different engine platforms from street to mild performance and off-road they all came back off and sniper was put on and I continue to use sniper never had an issue with it. Ive tried
fi tech on a few different engine platforms from street to mild performance and off-road they all came back and sniper was put on and continue to use sniper never had an issue with it all aftermarket EFI systems have issues the main problem with fi tech is customer support and the main problems I was having with the system would forget constantly and have to relearn
 
It's too late now, but since it's 4.3, was wondering why you didn't want to go with the GM TBI system?

2) Could you list each part of your fuel system in great detail including part #'s? (i'm back with one foot in the maybe FI box as i ,apparently, can't tune a q-jet. i may post a disaster thread in the garage section....)
 
vandelay industries said:
It's too late now, but since it's 4.3, was wondering why you didn't want to go with the GM TBI system?

2) Could you list each part of your fuel system in great detail including part #'s? (i'm back with one foot in the maybe FI box as i ,apparently, can't tune a q-jet. i may post a disaster thread in the garage section....)
Click to expand...

I wanted modern EFI features like being able to tune it myself, tune on the fly, and have live sensor monitoring/data logging. The idea of having to send chips off to get burned for any engine changes or only being able to use that TBI on a 4.3 and not a SBC or whatever I decide to put it on in the future is lame. Also I have vortec heads so I would need to use my intake with a throttle body adapter which probably wouldn't have fit in my engine bay.

I am using a fuel cell with a Walbro 255lph pump in a holley module. Some Russell Twist-Lok -06 hose and a hand full of fittings for my application. I have this fuel system because It supports Carb or EFI with just changing the pressure regulator.

If I was doing EFI only I would do the same thing but I would do a return line back to the tank from the throttle body and use the internal fuel pressure regulator.
 
Update on my Fitech. Its been great. Just shy of 1000 miles on it now. I haven't done any manual tuning yet. Its been doing so good on its own I wanted to let it go. I have changed some settings though, It will self learn the fuel table but its not going to change its own settings. I opened up the amount of short term fuel trim it can use and messed with some IAC speeds.

The biggest update is that I figured out that the FItech timing control is setup for a two wire magnetic pickup distributor. You know what distributors use two wire magnetic pickups ? If you guessed GM HEI you would be correct. Just gut out the ignition module, lock out advance, and phase the rotor and you are good to go. It can be even easier than that though. GM small cap Hei for the TBI motors already have the rotors phased properly and are locked out for fuel injection from the factory. SO gut one of those rather than a large cap.

I picked up this distributor, coil, new cap, rotor, and gear for $60. A MSD distributor for my engine is $400 plus the coil.

Bench tested it for function, removed the ignition module, and made up a little aluminum block off plate from an old license plate.

IMG_1573.jpeg
IMG_1577.jpeg
IMG_1582.jpegIMG_1581.jpegIMG_1580.jpeg
 
So, it appears that the packard clip on the rear of the throttle body does touch the Large HEI cap.......but shouldn't affect anything?

i should just copy your setup and i should be good to go. i'm just weighing all my options here as i can't get the q-jet to work anymore for some reason...........:frown
So close........yet so far. It's mynd boggling......
 
vandelay industries said:
So, it appears that the packard clip on the rear of the throttle body does touch the Large HEI cap.......but shouldn't affect anything?

i should just copy your setup and i should be good to go. i'm just weighing all my options here as i can't get the q-jet to work anymore for some reason...........:frown
So close........yet so far. It's mynd boggling......
Click to expand...

It may limit your base timing setting depending on how you stabbed in the distributor. The clip touches but thats fine. the only issue is the cap has the screws on it. If you need to rotate the distributor and one of those screws hits the clip. If that happens just move the distributor a tooth and re set the timing.
 
nvrenuf said:
How about a year+ update? Still like it?
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I got rid of it last year. Basically the story went like this.

I installed it, drove it for that summer, maybe 2500 care free miles. I dont remember exactly. It got parked for winter. Started and drove around maybe 5 times over the winter. Spring came, it started and drove once then it broke. Something died with the injector drivers. 8 times out of 10 it wouldnt do a prime shot when you turn the key on, and the injectors would never fire while cranking. If it fed it fuel while cranking it would start and upon transfering from start to run state the injectors would magically start working again and it would run pretty much okay. Some other quirks like not letting me update settings in the tune. After a month of back and forth with fitech I got an rma and sent it in. They had it for 2 months before i got it back.

The real kicker is when I got it back, it was still broke. This time the map sensor wouldn't read. unfortunately its built into the ecu. on top of it coming back broken, they scratched up the surface prying off the fuel rails and the new harness was electrical taped rather than heat shrinked.

I bitched and moaned with fitech and summit trying to get a refund, Finally summit agreed and I sent it back. I was a few months past the return window because fitech spent so long getting it back to me and trying to trouble shoot. I couldn't stomach the idea of selling it to someone else and they having to deal with the issues.

Now im running a gm tbi setup. 5.7l injectors, 7427 ecm, and I picked up all the stuff to burn my own tunes. the swap cost about $100 with another $100 in hardware to tune it.
 
Man, that really sucks. I’m just daydreaming and your story was sounding really good until the end. With what seems like a $1k plus jump to get from questionable “inexpensive” to dependable systems (like the Pro Flo) I guess I’ll keep tinkering on my carb.
 
Sorry to hear @TreeFarm

nvrenuf said:
Man, that really sucks. I’m just daydreaming and your story was sounding really good until the end. With what seems like a $1k plus jump to get from questionable “inexpensive” to dependable systems (like the Pro Flo) I guess I’ll keep tinkering on my carb.
Click to expand...
There’s no cheap easy smoking gun. If you want a reliable quality EFI, you’ll have to pay for it…
 
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