i have a 93 lt1 and i was just wondering what modifications should i do first on the car. is there any i can do here at my house? or do i leave it to the pro's?
I like the older cars w/o all these electronics lol
thanks

 

does these work?
can i make one by going to my local radio shack?
can help welcomed
thanks
chris

 

That's a resistor that plugs into the IAT sensor harness connector, and yes, you can buy a 4.7Kohm resistor at Radio Shack for 50-cents that will accomplish the same thing. But it isn't going to give you 20HP.... all its going to do is confuse the ECM. Your 93 ECM runs in "speed-density" mode. It needs an accurate inlet air temperature reading to accurately calculate the "density" part of that equation. If you feed the ECM bad info, its going to give you bad results.

The IAT resistor "spoof" works a little differently on the 94 and newer PCM's that operate in "mass air" mode, using a mass air sensor (MAF) to directly measure air flow into the engine. In the MAF cars, the IAT sensor is not used to calculate air flow, but appears to be used to add some extra timing advance to the values programmed in the PCM's spark advance tables. So telling the PCM the air is 57degF might give you a little edge with the timing.

A suggestion.... since you posted in "Computer Diagnostics....." appears that you are interested in performance gains through "tuning". Can we assume you are already aware of the basic steps to LT1/4th Gen performance like a cold air intake (CAI), a full 3" catback exhaust, etc.? If you need guidance on these items, post your questions on "LT1 Engine Tech".

You can get some gains through programming, even on a stock LT1. The target A/F ratios used at WOT appear to be excessively rich, and simply leaning out the power enrichment mode (PE) target A/F ratios will pick up a quick 15HP. Your 93 would need a new chip burned by one of the mail-order programmers that do a lot od business on these forums. The 94 and later models have the advantage of a flash programmable PCM, so its a little less involved to get a tune and keep it up to date with your mods. But a new chip for your 93 would be a good mod.

Just don't buy anything you see on eBay until you have asked the people here whether its worth it.... there are far too many scammers out there offering huge HP gains and high prices for stuff that you could do yourself for a small fraction of the cost. And you will never see the gains they promise anyway.

 

pcmforless did a great job with mine

 

wow thanks....i never knew there was that much of a difference between a 93 and a 94.......
"You can get some gains through programming, even on a stock LT1. The target A/F ratios used at WOT appear to be excessively rich, and simply leaning out the power enrichment mode (PE) target A/F ratios will pick up a quick 15HP. "

yea...i have a problem. my car when i get on it puffs gas out of the tail pipe. i know its gas because i had a friend follow me one day to my place and he said my car reeked of gas. I believe some one has changed the injectors=running way to rich. I dont know how to lean the sucker down. i need to get this done real bad since gas prices around kentucky are $2.05 <<<is this something i can fix thru the computer myself or would it be easier to take it somewhere or do i have to do something totally different not even involving the computer?


thanks for the help so far.

 

You need to get the pcm corrected and that should solve problems and give you more power.

 

The first thing the ECM does after it calculates how much air has entered the engine is to calculate how long to keep the fuel injector open (pulse width) to supply the required fuel. The ECM has to know how big the injetors are. The "size" (flow rate in pounds/hr or grams/second) is programmed into the chip. If someone changes the injector size, it could run rich.

The ECM can tell if its running rich, and within certain limits can correct for the excess fuel. But going to a larger injector without reprogramming (i.e. replacing your chip) is not a good idea.

First you need to determine if you have the correct injector size in the car. You should be able to pull a part # off the injector, and someone can tell you what it is.

If the injectors are the stock 22#/hr injectors used in the 93, you have to look at other causes of the car running rich. Excessive fuel pressure, leaks in the exhaust before the O2 sensors, misfires or faulty O2 sensors can cause this problem.

One way to evaluate the source of the problem is to record a data log of the critical sensors and ECM parameters. You can get free software to do this, using a laptop. Once you run the scan and log it, there are people here who can help you with the data.

I have an online guide to scanners, that sort of explains what's going on inside the ECM. Its for the mass air 94-97 cars, but a lot of what's in there is of use to you.

http://members.aol.com/InjuneerZZ/ScanMast.htm

Don't let the electronics overwhelm you. I bought my Formula brand new in 1994. When I popped the hood the first time, I had no idea what I was looking at, and what it all meant. A few years later I was able to write "the book" that a lot of people have found useful in learning what it is and how it all works.

You need to find a thread on LT1 Engine Tech that identifies all the differences between the 93 and the other 94-97 LT1's. There are a lot of differences, and it would be helpful if you knew what they are.