Just joined here and could use some help with my lt1 swapped Blazer. I have been driving it daily for a month now and enjoying it greatly but need more power!. First issue is I took it to get tuned this morning and ran into a couple issues...
The engine is out of a 1994 vette and I think it has stock internals but not entirely sure. Does sound like it has a bigger cam from the little bit of lope it has at idle and deceleration but don't know how a stock Corvette sounds. So from that little bit of info here are my questions.

I found out today it has a injector failing. I am looking into https://www.summitracing.com/parts/tfs-89036. I am running a 355 aerodynamics fuel pump, so will these work for my application?

Tuning is another huge issue as I just found out. I swapped from obd1 to obd2 for better tuning options. I am running a 1997 firebird/Trans am ecu that Holly just bought the rights to and now all the lt1 tuning software is locked down and unusable. My tuner told me this morning to either swap to obd2 version 3 or buy https://jetchip.com/shop/chips-modul...-programmer-2/. What are your thoughts for anyone that has experienced this? I would like more info on what it would take to swap to version 3 obd2 but ultimately want what works best and for the longest.

Fuel runners are my next question. I need to change my fuel lines to be NHRA and SCCA legal and have been looking for better fuel runners that I can use an fittings on instead of the stock fuel line clips. Right now I am using some cheesy plastic adapters from Napa that are working but want to be legal for racing.

Last question and not sure if I should start a new thread for this or not. I have a lt4 that I originally bought for my swap and it ended up needing a crank from being bent in a wreck. I couldn't return it because it had been over the thirty day return policy so stuck with it. So I am thinking about rebuilding it for forced induction, but read a few places that the LT series engines don't like turbo's and to go supercharger. Is that true?

 

you read wrong, its a 350 you can put anything you want on it. Most dont gap their rings properly or run cheap pistons then wonder why things go boom.

 

Tom Wong of Wong's Performance can tune the engine for you. He is located in Vancouver.

 

The 94-97 lt1/4 pcm is flash programming. You need to find a dyno tune shop who is willing to work on it. The LT!/4 is not as popular as the LSx. The 96-97 pcm is obd2. The 96-97 pcm would have to be programmed for a 94-95 engine since it doesn't have a crank sensor.

With your LT4 if it got hit hard enough to bend the crank: you want the block thoroughly checked for crack(s). There is only one LT gen 2 block casting number, only the Corvette was 4 bolt main. Adding forced induction is only money since engine needs built any way.

36lb injectors are too big for stock engine. The stock injector is 24lb. FIC is this sites popular injector vendor.

 

Thank you for the info. I have been a carb guy for years and this is a huge learning curve as I go. I follow Tom Wong on FB but have my own tuner that I want to use but thank you.
The engine in my Blazer isn't the one that needs rebuilt. I do plan on tearing down the other lt4 that I have and have it checked for cracks before I start buying parts for it and building it. Been down that road before and it wasn't fun.
I will look into the FIC injectors, thank you

 

This post has been all over the place! Wow!

The original problem was that the owner felt or heard an occasional ping in fifth and sixth gears while under a load condition.

We can re-invent the software or just solve the problem the car is having. I would prefer just to solve the issue that is affecting the OP's Corvette.

I would say that from the mention of a slight ping in the higher gears under a load would make me look first at the timing to be sure it is dead on and the second thing I would look at is the Oxygen sensor as when they age they lag and in higher gears with the engine under load. The engine is running faster and needs fast responses from the O2 sensor to keep the mixture perfect. As the O2 ages it looses some of the signal and it becomes narrower. Instead of going from .1 to .9 volts it will go from .3 to .7 and it gets worse as they age (This is an example, not true numbers). Between slowing down their response time and the less accurate output a bad/going bad O2 could easily cause the issues that were mentioned. Detonation is very easily caused by a faulty O2 sensor at higher RPMs. While the O2 is out of the car be sure that there is no pressure blowing out the hole when the engine is running. If air is blowing out of your O2 mounting hole then you might have a partially clogged catalytic. If it is not the O2 then I would watch the output of the MAP sensor as they too can cause misses under loads.

I hope that this helps the original poster as he should be able to fix his car without changing any software. Software to me is the last resort. I suspect it is one of the two sensors mentioned above.

Best regards,
Chris

 

Your tuner told you to switch to OBD 2 bc he likely isnt as familiar with OBD1.

that said, OBD2 might be your best option for boost.

there is a work around from tunercat for OBD1, on 92-93 speed density ecm’s , that allows those owners to use a 2 bar MAP sensor to dial in fuel with boost. I am doing this on my 93.

no idea if it exists for the $ee computer of your 94 - its sequential fuel inj so its a different can of worms.

holley has some amazing , very user friendly, engine management system (for fuel injection) that I would switch to if i was putting in an aftermarket ecu system.

never heard thAt lt1’s ‘dont like turbos’

 

Folks go back and read post one from 19 months ago. The op isn't even talking about a Corvette, just the engine that was snagged out of a Corvette and has an unknown heritage.