FI Tech Frustration is back again

CopperNick

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Feb 20, 2018
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Nick, the AFR gage has a sender that looks a bit like an oxygen sensor so you could likely reuse the place on the head pipe where the Fi-tech was reading if you wanted to add one.
Now that is very interesting to read. The O2 sensor is just occupying space for now. They do make screw in caps to close them off and I do happen to have one but if I can put that bung back to a better use................ Well. Have to visit the speed shop next week for some bits, have to ask Dave if carries them.



Nick
 
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64nailhead

Goat Herder
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Dec 1, 2014
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Now that is very interesting to read. The O2 sensor is just occupying space for now. They do make screw in caps to close them off and I do happen to have one but if I can put that bung back to a better use................ Well. Have to visit the speed shop next week for some bits, have to ask Dave if carries them.



Nick
You can buy bungs, plugs and bung and plug kits on Amazon pretty cheap. I ordered a pack of 5 and still have a couple left over.
 
Oct 14, 2008
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I’ve developed a hypothesis about FiTech. FiTech is owned by Holley, Edelbrock or some other carb manufacturer with the sole purpose of trying to convince people to never consider anything other than a carb again.

I know so many people that have bought one and ended up with a carb. I’m beginning to put 2 and 2 together to come up with an awesome marketing ploy.

What’s next, throw out the radials and start buying bias ply tires?
This makes a lot of sense, many people just say F it and go back to a carb. I am running an AEM AFR. It is a great tuning tool for my Qjet. I could not believe how much a 1/4 turn on the mixture screws on a modified carb makes for idle AFR. Also swapping a hanger made more difference in full throttle AFR than swapping secondary rods.
 
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64nailhead

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CopperNick

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Feb 20, 2018
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Wouldn't need to replace the bung as the existing one is in good condition. Would need the correct sensor and the matching gauge and a place on the dash to hang it. Thinking here that my preference in the gauge department would be a solid state unit with digital readout and about half the thickness of a deck of cigarettes. Something with those dimensions would sit nicely on the ledge where the programmer used to reside.

Went to work, and from there to the speed shop. Returned some extra bits that did not get used for the install, confirmed that I wanted the spacers for the base/tray, picked up one of the Edelbrock versions of the Cable Bracket, plus my LIngenfelter O-rings for the injectors on my LS Orphan, and a spare bung for stock as the one I have now will get consumed during the construction of the new heard pipe for the S-10.

The hot wash to determine what went wrong came up with two probabilities. Because of the consistent stall out during initial acceleration, the first likely culprit is probably the TPS or Throttle Position Sensor. As 64Nailhead mentioned, The sensor could have been tested using a thin needle or pin but by then the whole system had already been decommissioned.

The second and equally likely culprit could be the fuel delivery sub-system. The booster was never meant to be the permanent solution to getting fuel from the tank to the injection body. Rather it was the field expedient method that put the vehicle on the road for the time being. Time being turned into 8 years and it is quite possible that the booster pump was slowly failing. An in tank pump would have been the best alternative but GM vans all the way into the nineties had a raised dome in the middle of the roof of the tank which formed the location for the sending unit. That did not leave much empty area sufficiently large enough and flat enough to accept a second hole into which the electric pump could be installed.

If I choose to attempt to repurpose the FI TECH 4 barrel TBI unit that I have, it will most certainly get a new TPS sensor. The candidate for it at that point would be my Monte Carlo as it has very little left of the original fuel system; just the engine pump and the tank. While the pump is serviceable, the tank has been sitting since the car was parked and whatever amount of gas that remained in it has by now deteriorated to consistency of shellac. Getting a new one with the built provision for high pressure fittings would let me run hard line from the tank to an in line fuel pump, and yes they are reputed to be noisy but so are my mufflers, and then from it to a filter regulator that would allow me to run a returnless system. All this is presently in the world of dream time as there are more important projects scheduled for the Monte before I give some consideration to fuel delivery.

if nothing else I would want to start and run Project Regress on the stock carb and fuel delivery system until t got all the "teething pains" sorted out. Going KISS with a new project just re-introduced to the road keeps the variables down and makes getting re-acquainted with my toy potentially a lot more pleasurable and fun.

As for the AVS, it starts easily and runs and responds well. The only thing I have done with it is to revisit the idle stop and drop the idle down to a true 1000 rpm as displayed by the Tach. That tach, for its part, is an Autometer and for an analogue unit is fairly accurate. That was one thing about the FI Tech programmer gauges that always bugged me; the on screen Tach would never stay stable; it consistently bounced around from reading to reading and up and down through a range of values. Too sensitive.

Going to drive the van with the setup as is for now. I am ambivalent about tweaking the tensioner sleeve on the TV cable. The R4 shifts nicely and 1st/2nd is not as hard initially as it used to be with the FI setup. The only thing that bugs me is that 3rd doesn't come in until after 30 mph, which in stop and go traffic, means you spend a lot of time in 2nd at the top end of the shift range but not high enough to prompt the shift to happen. One more tooth might shorten the shift just enough that it comes in slightly earlier and takes some of the stress off the 700. JUst me thinking aloud here.



Nick
 
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Texas82GP

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Apr 3, 2015
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565bbchevy

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Aug 8, 2011
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Michigan
I’ve developed a hypothesis about FiTech. FiTech is owned by Holley, Edelbrock or some other carb manufacturer with the sole purpose of trying to convince people to never consider anything other than a carb again.
And Edelbrock just released a new Holley style 4 circuit 4 barrel carb.
 
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CopperNick

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What's so new about that?? The type1850 model 4150/4160 has been reverse engineered, analysed, modeled, dynoed and creatively cloned by at least two other mfgrs all ready. Seem to recall that both FAST and Quick Fuel have "versions" of the square bore dinosaur (Hee, Hee) that initially came into being as a Ford application and quickly got adapted to just about anything that used a carb for fuel delivery. Think at one point they even had them on riding lawn mowers!!

One of my shelf rats is an 4150 that is so old that it is on its third throttle/base plate and now runs both cathedral bowls both primary and secondary as well as their matching metering blocks. This mutt is so old it has its own jet box with easily a dozen different numbers on hand.

When it followed me home back in 1985??, it sure didn't look anything like it does now. it is so old (How old is it???) that it exhibits pretty much same degree and extent of crotchety attitude that most bio-organic seniors do. it hates cold, moisture, humidity, snow, and urgency. I think that the only place it ever ran well was at Sturgis SD in August at about 100 F . Hot enough to fry bacon at 7 AM and it didn't even need priming or choke to come out to play.

The only reason I went FI was to eliminate the almost daily need to "tune" the thing. There was no way to easily gain access to the engine bay; it's a van, DUH! And I am still not done with that particular FI TBI lump. Now I wish I had an engine start up stand; just for Sh8ts and giggles I'd load one of the hanger queens into the stirrups and do a little bit of automotive proctology to see what might be seen.



Nick
 

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