dwayneellis2003

Ok so here's the deal.....surely someone here has had this happen.....

I've got a '94 Z28 LT1-A4. The car has 2 alarm systems in it, the original from the factory and an aftermartket "Code Alarm" system. The last time it was cranked, it ran fine, with no problems whatsoever. The car sat for about 2 months, and i went back home to crank it up.....nothing......charged the battery (battery is 4 years old), and tried to crank the car again....still nothing....replaced the neutral safety switch......still nothing......replaced the starter....still nothing.....tested the new starter and it works. tested the neutral switch and it worked too......found out the neutral switch had to be "calibrated" and had someone do it that "claimed" to know what they were doing.....still didnt fix the problem. One mechanic told me that my car could be in "theft" mode, since i had told him that i bypassed everything and ran a push-button from the battery to the starter. The 4 "local" dealerships all told me the same thing about theft mode: " if the light isnt on, the car isn't in theft mode, plain and simple." and they also "would just have to look at the car". My question is this.......When the car was wired to the push-button, it would actually start, when the key was ON, but would only run for about 3 seconds, and then something would kill the engine. NOTE: when i turn the key on, everything does as it should and everything lights up like it should, but when you turn the key to START, nothing goes DIM, the door chime goes off like its supposed to, but the car makes no attempt to start. also, the battery gauge goes up, as some voltage is freed up when the car is supposed to engage the starter. I REFUSE to take the car to a dealership, because i know i can fix this myself, but i didnt expect to run out of options first.

I have already checked every single wire, fuse, fuse block, fusible link, relay....everything i could find, and i have replaced those things as well, but to no avail.....everyone i ask is leaning towards the PCM (computer under my hood) as needing to be replaced. I opened up the case of the PCM, with the hopes of visually inspectiong the board, nonly to discover that the chip is the only complex thing on that board, and there was no apparent damage. The PCM was also replaced 3 years ago, supposedly......bought the car from a life-long friend....

I'm REALLY hoping that the ECM isnt the problem, as i had to take the entire dash completely out of the car just to be able to reach it, since it sits directly behind the gauge cluster......

If the PCM needs to be replaced, would it ACTUALLY let the car crank with the push-button, and run briefly, but then die? Obviously the car wouldnt start with the key, which was why i bypassed that. Im wondering if the PCM or ECM is saying " hey, i didn't tell you to start." and then killing the power to the engine......Also, the codealarm system was unhooked, just to see if it made any difference. it didnt, plus i saw it had ignition wires running to it, so i hooked it back up.....the key even has a fresh battery in it, and the alarm SEEMS to be working properly.

my questions are....can i buy an after-market chip, like i had originally planned? or do i need to replace the entire PCM. Other than the chip, there really isnt anything on this PCM that can go bad. Could the ECM be causing this instead? If so, is there an easier way to get the ECM out, without having to take the entire dash out? How EXACTLY is a neutral switch supposed to be calibrated, or is that just completely bogus all together. I also have a ohm-meter so i can get some read outs from everything, but i have no clue what to expect from where.......also, i should mention that i think the car has some kind of small short somewhere on it, because the batter would die, if the car wasnt started atleast once every 2 weeks....but then again, that battery wasnt supposed to last 4 years and shouldve been replaced by now, im sure.


any help on this would be GREATLY appreciated. ive got the money to get it fixed, but im not gonna pay unnecessarily jsut to do it. no point in paying what i paid for the car, to the dealership just to get it fixed. i'll gut it completely and drop my new 454 in it before i do that.

chevyz4life

Do a search on ignition switch maybe that's the problem your having. Just trying to give you some more ideas

shoebox

If the car would start before and then die, that "something" was probably the PassKey system. Now that it won't even crank, it still could be. You need to do some testing with the ignition circuit to see how far power is getting in the cranking circuit. (my Tech Page has schematics, but you are going to have to allow for your alarm and pushbutton start)

As far as changing the PCM, it's not under the dash, it's in the engine compartment.

burnout96

FYI, code alarms are not none for longevity. I worked as an installer at Circuit City for 3 years and we only carried CODE ALARM for about 6 months before the company dropped them. The brain system of the CODE ALARM is known for going bad and doing so quickly. That would be the first place i check, it would explain allowing the car to start but only run 3 seconds at times and then not start at all

-matt-

TraceZ

completely remove the codealarm and return all wiring to stock. Then go from there using Shoebox's schematics if there is still a problem.

dwayneellis2003

ok....I think i need to clarify a few things. The car will NOT start with the key. I have no clue about how to completely remove the alarm and returning the wires back to how they were originally isn't something i think i can do, atleast not without some sort of guide i mean, i can remove the box, but as far as cutting wires and whatnot, im not sure i want to try that.....would just removing the alarm box itself work?

I tied into the starter wire and bypassed the ignition system completely, and just ran that starter wire through a push button and then wired that to a distribution block that i installed by my battery, for my sound system. so far, thats the only way i can start the car, and like i said previously, i figured the PCM was saying basically " WTF! i didnt tell you to start.", just before it kills the engine.

i have actually tried to remove the alarm box, but didnt return the wiring to normal (because i dont know how it was originally) and it didnt make any difference. ofcourse, this could simply be me being retarded, but i assumed that the wires would still be part of the complete circuit, but that the alarm simply "intercepts" signals.

ive called about 10 dealerships and they've all told me that the passkey system isn't what the problem is, and they said something about theft-mode, or that if someone attempted to start the car with a key that didnt have the chip on it, that it would lock the PCM down, and wouldn't always illuminate the "theft" light. then again, it WAS a dealership....'nuff said......dealerships around here couldnt figure their way out of a paper bag.....

i completely forgot about the ignition switch, but wouldnt it be combined with the lock cylinder? i DO know that my '92 25th anniv. Z28 had the ignition switch mounted on the right side of the steering column, but my '94 isn't like that, and i've even looked on google and still cqan't find the damned thing, unless ofcourse, it's built into the key ignition cylinder......i have no clue.....i'm gonna go pick up a new igniton switch for it and try that.

i'm also looking to order a new chip for it as well, but ive got a few questions about that as well......can i just buy any aftermarket chip for that make & model, and drop it straight into the PCM and go? or is there something else i need to do first....also, if it's "plug & play", does anyone have any recommendations for any top of the line chips? i want the most bang for my buck and dont care about the amount, but dont want to top $500.

i'll let you guys know if the ignition switch takes care of the problem after christmas, which by the way, MERRY CHRISTMAS GUYS AND THANKS SO MUCH FOR YOUR HELP!

RUDEDOG

The ignition switch lives on top of the steering column.

shoebox

You can find wiring diagrams and ignition switch info on my Tech Page.

Your PCM uses flash programming and not a "chip" to reprogram it.

dwayneellis2003

ok so now im confused. does that mean that there is no such thing as an after-market chip for my car? or does that just mean that there isnt any point in buying one, and that i should get the ALDL (OBD-I) cable and reprogram the chip.


also i really appreciate the info about the ignition switch......wish i wouldve thought about that $300 ago lol....ive got to go buy a steering wheel puller, and the new switch when my check comes in on the 11th


**EDIT** ok ok, forgive me, but for some reason, i thought the knock sensor was the "chip" for the PCM. by "chip" i mean, the chip that gets programmed, when you reprogram your car with performance specs.

shoebox

There are some "add-on" chips that you can buy, but that is not what you want. Your computer uses flash programming and does not have a replaceable chip. You can load your own program with suitable tools or you can send your PCM by mail to have it reflashed to your specs. Some places will even send you a hand held device that will load your tune, then you send it back.

The knock module has no changeable programming. The knock sensor is not in the computer-it's on the engine block.

You don't pull the steering wheel to replace the ignition switch (if you read my guide). Replacing the key cylinder would cause you to have to pull the steering wheel. The switch and the cylinder are two different things.

dwayneellis2003

I read your guid, but i mistakenly typed "sensor" instead of "module".....mainly, i was trying to figure out what the chip was in the PCM, but now i know, thanks. on the other hand, your guides DID answer a lot of other question i had.....as far as removing the steering wheel goes, when i replace my ignition switch, im replacing my key cylinder as well, thats why i mentioned it. also, i didnt realize how scatter brained my posts were because i was in a hurry each time i typed one.

i dont suppose you have any reecommendations as far as handheld programmers, do you? ive found a few from jet and hyper-tech, but jet's website absolutely sucks and isnt very informative at all. i am simply looking for the most horsepower and torque gain that i can get from the computer side. i was actually leaning towards handheld programmers anyways, and my spending limit is $1500 for that specific thing. on the other hand, im extremely grateful for you taking the time to help me out with this. i just have so many questions about this, and if you have any other ideas about more efficient upgrades that i can perform without tearing into the engine, that would be awesome as well.......as far as mechanics go, i've always done my own maintenance, but the only things i dont do are rebuilding engines and transmissions, rear ends, and suspension work, but thats about it, and obviously, i get the names wrong more often than not lol

Injuneer

There's not a lot of added HP or torque, without some mechanical changes to the engine - either bolt-on modifications, or internal changes. For a stock engine, you can pick up 10-15 HP with tuning, by leaning out the power enrichment (PE) mode target A/F ratio. A mail-order tuning shop can do that very cheaply, and then provide you with additional tunes at reduced cost as you upgrade your engine. "Search" on Trifecta, pcmforless or madtuner.

Or you can get tuning software like TunerCat or LT1_Edit to make the changes yourself. You can't do much of anything with a "hand held" tuner. The Hypertech unit is useful for changing rear axle ratio, setting shift points, changing fan on/off temps, raising rev limiter, removing speed limiter, etc. But the "power tuning" is a complete waste of money, and has been shown to lose HP, unless you opt for the 160*F thermostat and corresponding lower fan on/off temps.

dwayneellis2003

ok so the tuning is basically what i was talking about really. im not looking forward to having to tear into this car and replace a bunch of stuff, because thats too much downtime.... thats why i was looking for things that were relatively quick. at first i thought i was gonna be able to just sit down and order a whole new computer or chip or something online and then just slap it in and go, but everyone i ask about things of that sort, says that similarities and items of that nature DO exist, but i should avoid them like the plague....so that pretty much killed that idea for me....

there are a LOT of camaros here in Waco...ESPECIALLY the body type i have.....and apparently they dont believe in having exhaust pipes either...dont know how in the world they manage to get away with that.....

shoebox

If you want to do a tune that has virtually no down time, look up Trifecta when they get back from vacation. They can make you a custom tune, send you a device to load it, then you send the device back to them.

http://www.trifectaperformance.com/

dwayneellis2003

well....thats all well and good, but still one problem remains......

i have replaced the starter, battery, key cylinder and ignition switch (today), neutral safety switch, and even disconnected the alarm (was still wired for the alarm, but the alarm box was just totally disconnected), replaced every singe fuse and relay.......thats quite a bit of money......i have even physically traced every single inch of wire in this car and still.....turn the key....nothing......yet if you turn the key to ON and tie into the starter wire and touch it to the positive on the battery....the car will turn over and actually run.......for about 3 seconds.....then its almost like all of the sensors on the engine lose power at the same time, and it dies without even a small sputter......

the car ran fine the last time i drove it.....then i didnt crank it for 2 months.......now im in THIS situation lol

im still refusing to take it to a dealership, just too darn expensive......$500 worth of parts that more than likely werent even messed up....sitting on $1400 of brand new rubber......rebuilt 327........just sitting there going to waste, and im about to say screw it and just sell it.

the only things left that i can think of to do, would be replace the ECM and PCM and possibly the entire steering column........been thinking about getting a diagnostic tester, but the last one i bought had my exact car listed and it didnt do anything except kick on the fans in ABS mode, and for ECM mode, it was like there wasnt anything there at all and the car would actually start.........any ideas?????