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LT4 FIC LT4 fuel injectors work..........AWESOME! (Caution: long read!)

1996 LT4 Topic

LT4man

Well-known member
Joined
Jun 25, 2003
Messages
2,217
Location
Chicago
Corvette
96 Collectors Edition LT4
A little background. I owned & operated an auto & truck repair shop in the Chicagoland area for almost twenty (20) years. I still keep up with all the latest in the automotive industry. Still work on a variety of vehicles for clients & friends. Have almost forty (40) years experience working on domestic & foreign cars & trucks.

I bought my 1996 Collector Edition coupe with the LT4 new in March ‘96. Over the years I myself installed many bolt-on modifications. Upgraded air intake area, ignition system. Designed a custom 3” exhaust system which was fabricated and welded by a good friend.

I did a mail order tune in 99. Finally, a couple of years ago, I had the guys at Speed Inc. in Schaumburg, IL do a dyno-tune. My LT4 was running strong.

In January of this year, I started searching for replacements for my OEM Rochester Multec fuel injectors which now had over 105,000 miles on them. I searched the threads here for solutions. Luckily for me, I ran across Fuel Injector Connection. I saw where Jon had taken the Bosch Design III injectors and rebuilt them to flow exactly what my injectors flowed. A fellow forum member, Mekanic, installed these injectors into his LT4 and was thrilled with how they worked.

As you can see, I take my time when it concerns my Vette. I sent an email to Jon at FIC, and he called me back immediately. We talked about what I could expect from his injectors. I learned the ‘96 Multecs no longer have the coil windings exposed to fuel. Jon told me they would probably ohm out pretty good. That did not mean, though, they were working up to their potential.

I ohm tested all of mine. 12 ohms all across the board. Score “one” for Jon!

Spent the next week in Bowling Green for a cruise. When I returned I emailed Jon again. Again, he called me back immediately. I was starting to be surprised at his excellent customer service. Remember, earlier, I had said I owned a shop and had dealt with all sorts of vendors. Jon was inching his way up to the top of my “Top Ten” list.

On Tuesday, in a purely “preventive maintenance” move, I ordered NEW Bosch Design III fuel injectors from Jon. He had taken these apart to replace parts to enable them to flow identically to my OEM Rochester Multecs. I live in Chicago. FIC is located just outside of Atlanta, Georgia. They arrived on Thursday. I was surprised but extremely happy. Score “two” for Jon!

On Friday, I installed them. Took me about an hour. I like to take my time on my Vette. Anyone could do these in about 45 minutes.

My fuel rails were empty. I cycled the key twice before cranking to energize the fuel pump and fill the fuel rails. My engine started FASTER than it had been starting. The idle settled to a “smooth like glass” RPM. I used to have somewhat of a lumpy idle. Always thought all LT4s ran like that. Not mine anymore! Score “three” for Jon!

Also, the noise coming from my old injectors was gone! Recently, I thought I needed to investigate an exhaust or lifter noise. No need for an investigation now! I really cannot hear these injectors “click” at all. Score “four” for Jon!

Driving my Vette put me over the edge. I have spent the last two weeks driving and enjoying my new found power & smoothness. At any throttle tip-in, the response is immediate! From starting to idling to accelerating……….I have not seen a mod in my life give such results so quickly and inexpensively!

Did I mention Jon finally worked himself up to the top position of my “Top Ten Vendors” list? Work might be the wrong word. Dealing with Jon and his company was absolutely the most effortless experience of my entire automotive career.

Too many times a forum becomes a sounding board for all the negative and sub-standard customer service we run into. Not this thread.

I congratulate Jon on being the person he is. Knowledgeable & eager to share his knowledge. Hands-on. Timely. An all-around nice guy. Fabulous company. Unbelievable customer service.

Thanks, Jon!


AFTER REPLACING YOUR FUEL INJECTORS, PLEASE SAVE THE :w!
 
Injectors

LT4 man that was a great article. I am out of the loop as far as the new fuel injectors systems. I have a CE LT4 with 51,000 on it. I have been a gearhead since the 50's and 60's on corvettes. I am very anel on my maintenace of my vette. Just a quick question on the injectors. Are the OEM injectors prone to fail slowly, or they a quick failure? My vette is running strong, but will I notice a change as far as fuel is concerned with the injectors. I will use your souce on the injectors if they are bad. Should I have a set of these on hand if mine go bad. Sorry for the stupid questions, but I plan on doing all the work I can on this car. Thanks Larry:w
 
Larry,

Remember, there are NO stupid questions! Let me see if I can help you out!

The 1996 Rochester Multec fuel injectors (the OEM ones in your LT4) are pretty good injectors. In 1996, Rochester redesigned the Multec. They removed the fuel passing over the electrical coil windings in the injector. Previously, they ran the fuel over the windings in order to cool the windings. I believe they figured out that the injectors were failing because of that particular design feature.

When I ohm tested my OEM injectors, they all showed 12 ohms. All of them. Jon had warned me that I would probably find that result.

Just because my injectors ohmed out perfect, did not mean they were not failing. It just meant that the windings were in good shape. Not to say anything about the mechanical parts in the injector. Mine were making so much noise, I thought I had an exhaust noise or noisey lifters!

Since I replaced mine, my engine is incredibly quiet and smooth.

With only 51,000 miles on your LT4, it is anybody's guess if the OEM injectors are starting to fail.

But...........................and this is really a big BUT.....................................

The atomization of the fuel in the Multec injector is lousy compared to the atomization of the Bosch Design III injector. How do I know this? Check out Jon's videos on the Corvette Forum. It is a sticky in the C4 Technical & Performance section.

My Vette starts so quickly and has so much more power and response. This is attributed to the better spray pattern in the Design IIIs.

So, in answer to your original question. I think you WOULD see a definite difference if you changed out your injectors. And why would you want to wait for certain failure when you can enjoy them now?

Hope this helps!

Gregory
LT4man
formerly known as lt4man :D

AFTER UPGRADING TO THE DESIGN IIIs, PLEASE SAVE THE :w!
 
I would give Jon a call. Depending on when & where he obtains his injectors would influence his pricing.

I paid LESS than $300 for eight (8) NEW injectors including shipping from Atlanta to Chicago. His refurbished injectors cost even less.

AFTER ORDERING YOUR NEW INJECTORS, BE SURE TO SAVE THE :w!
 
A truly interesting and informative read LT4man. Hats off to you. Hats off to Jon.
RG

Thanks, good buddy! I just calls 'em as I sees 'em! :w
 


In 1996, Rochester redesigned the Multec. They removed the fuel passing over the electrical coil windings in the injector. Previously, they ran the fuel over the windings in order to cool the windings. I believe they figured out that the injectors were failing because of that particular design feature.

When gasoline sits too long it turns to a "varnish" type substance (which is why the injector flow machines use heptane instead of gasoline). When this oxidizes it might be conductive, and may attack the lacquer finish that is typically found on coil windings (as well as the copper itself, maybe)...IF that happens you would definitely have a faulty injector.

Not really relevant or important...just more useless babbling. :L And possibly completely wrong!
 

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