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Discussion Starter · #1 ·
Hi everyone I'm new to here
I just bought a 2001 pontiac firebird formula V6 yesterday and the problem is that it stays running for a bit then dies out the seller told me that they lost the chip to the vehicle and the seller called a locksmith
Then the locksmith did a VATS bypass and after that they couldn't keep it running so I towed it to the house and started checking it out and cleaning it since it has been sitting for 1 1/2 - 2 years and it starts for a couple of seconds but running very poorly hesitating to stay on then dies then I tried pulling a pcm IGN fuse then putting it back while switch on i could hear the fuel being delivered to the fuel rail but it like 7 times then tried running the vehicle and started up acting the same but stays on for like 2 minutes now ..

These are things I have looked at and done and thinking doing ..

I see the security light flashing on the dashboard don't know if it affects it ..

While running the vehicle tried giving it gas won't even accelerate
And sounds like it not getting to much gas and dies out ..

Gonna empty out the gasoline tank and put new fuel

Replace the fuel filter

Would appreciate if the community can help me out
THANKS 馃憤
 

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Security light flashing means your vats security system has detected a problem and has shut off the fuel injectors. You said a vats bypass was done. But a vats bypass to most people involves inserting a resistor into key lock wiring that simulates the correct key.

Did the person installing bypass measure the resistance of the key pellet? Then add resistors of the correct resistance? Also did they unhook the connector from the key wiring so system doesn't read an incorrect resistance?

While key not reading correctly is the most common problem, another is when body control module (BCM) malfunctions. The BCM in these cars are known to fail. The vats electronics are embedded in the BCM, so replacement or repair of BCM might be needed.

If key reading is correct, BCM sends PCM a 50 hertz square wave signal. This allows PCM to turn injectors on. You can avoid BCM replacement by buying a 50 hertz signal generator module. They're cheap and found on ebay, amazon, etc.

With this module you will send the 50 hertz square wave signal directly to pPCM. Fuel injectors will work.

To assist you in wiring in the bypass module here's a link to the 2000 factory service manual.www.mediafire.com/?40mfgeoe4ctti

And welcome to the forum. 1 last thing, all 2001 formulas had the LS1 v8 engine in them.
 

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Discussion Starter · #3 ·
Thank you for the info and docs you have provided will check them later .

Sea dog
Is this the module you talking about
50 hertz signal generator
Font Video game accessory Gadget Home game console accessory Multimedia
 

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If the vehicle sat over a year with Ethanol blended fuel in the tank, your fuel pump is probably shot.

The flashing of the SECURITY lamp as well as VATS operation is explained HERE.

This is the relevant section to your situation - "The SECURITY lamp will also flash at once per second if a new, unprogrammed TDM is installed and there still is a defect in the key reading circuit. The engine will start in this condition, though."

As the engine is starting, ignore the SECURITY lamp, and pursue this like any other vehicle beginning with TEST FUEL PRESSURE.

When you cycled the key 7 times before starting, you built up more pressure in the line than the pump is delivering on initial prime. That is why it ran longer. 100% a fuel delivery problem. The only question is, is it the pump, filter sock, fuel filter, fuel pressure regulator, or clogged injectors.

It is very common for vehicles NOT DESIGNED FOR ETHANOL to have bad fuel pumps after sitting extended periods. This isn't a Pontiac thing, it's all "old" cars. Pre-2004 or 2005 in the USA if I remember correctly. If you're constantly driving and filling the tank, ethanol isn't a problem. When they sit over 6 months though, thats when the problems start, and the longer they sit, the worse it gets.

Ethanol is nasty stuff for systems not explicitly designed for it. First and foremost, it absorbs moisture, so things that wouldn't normally rust for example, now do.

Also, is that a V6 or a V8. No Formula or Trans Am left the factory with a V6. Ever. There were packages available for the base V6 model such as W68 and Y87 that made them look like Trans Am's and even had some of the performance "upgrades" like 4 wheel disc brakes. ...but they are most certainly NOT Formulas or Trans Am's, and should not be badged/stickered/referred to as such. If you truly have a Formula, it's a V8, and that matters for what comes next...

...a link to download the Factory Service Manual. It will assist you greatly.

Just be sure to refer to the appropriate V6 or V8 section.



Good Luck!
 

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1994 Firebird Formula 381ci LT1 / TH400+GV O/D
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The 50 Hz bypass module is specifically made for the GM PASS-Key II security system.

Example:

 

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Discussion Starter · #6 ·
Well I finally changed the fuel filter and checked the spark plugs added new gas
Then I started looking around the engine because it kept doing the same then saw a sensor bottom of the throttle body actuator and said let see what happens
Pulled out the connector and turned the engine and was like what the heck ... The car started running fine was about to drive it and wasn't able to accelerate the car kicked in the security turned the car off tried turning it back on and no go ..

Now I guess I need a vats bypass module.or try to find the correct value of the resistors to put on the lock cylinder cable

THANKS for helping me out guys with everything 馃檪(y)
 

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There are only 15 resistors. Everything you need to know is in the link I gave. I've used resistors from old electronics to build "resistor packs" to plug into the harness. Do not cut wires as suggested in the tutorial, it is not necessary. You can just unplug the 2-wire harness to disconnect the ignition barrel and slip the legs of the resistor into the backside of the harness end that leads away from the ignition barrel. Friction and a good tight wrap of electrical tape hold it all in place just fine.

It sounds like the engine is running for longer than a simple prime of the fuel system would support if the security system was shutting the fuel pump down. You really should test fuel pressure. When VATS is activated the fuel pump AND starter are disabled. You have both. What you discribe is fuel starvation in my eyes, not VATS.

Best of luck to you.
 

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When you unplugged the throttle position sensor, the computer would not open the throttle body any more than idle. The 2002 firebirds all have a drive by wire gas pedal system.

I can't say if the bypass module you show is correct, because it doesn't list the specs. But any signal generator that has a 12 volt input and a 5 volt square 50% on/off time output, will work on the car.

Those one's that Injuneer listed will work fine and there will be no adjustments to the input voltage & output signal needed. Their downside is they usually cost more than the signal generators on ebay, amazon, etc.

I've used the one from Injuneer's link. It worked well for about a month, then failed. I can't say if it was a random defective unit, or if all are like that.

There's another bypass module out there at Painless Performance Products. It, however, needs a 5 volt input voltage. So for it to work, you'd have to splice into one of the 5 volt lines going to sensors. And it's expensive.

I do havee one just like the one in your pic. However, I've never tested it. But it does take a 12 volt input. The output is adjustable for hertz and duty cycle. Also I don't know how long it would last. If you choose that one, better buy 2, just in case.
 

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1994 Firebird Formula 381ci LT1 / TH400+GV O/D
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Before we go any further, please answer the question that has been asked.

You stated:

I just bought a 2001 pontiac firebird formula V6 yesterday
You were asked:

Also, is that a V6 or a V8. No Formula or Trans Am left the factory with a V6.
As has been pointed out, there is no such thing as a 4th Gen Formula with a V6 engine.

Please clarify this, as there are significant differences between the engines, and that will affect the help you get.

You need to carefully read the responses, and answer any questions that we ask you.
 

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1994 Firebird Formula 381ci LT1 / TH400+GV O/D
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Dealership told me today it is a 2001 pontiac firebird V6 3800 series was calling to see if they can provide me with info about the key
That would be a "base" Firebird. The Formula is an upgraded model with a 5.7L LS1 V8. The V6 and the V8 have radically different ignition systems. But the PASS-Key II security system is common to both models. The other major difference is in the throttle body with the sensor you unplugged. The V8 has a conventional cable that actuates the throttle. The V6 has an electronically controlled throttle, no cable.

If the starter cranks the engine, the key resistor is not the problem. Once the engine starts, a failure of any component in the security system while the engine is running will not shut down the engine, and when you do shut down the engine, it can be restarted even if the problem continues. All of this is very clearly covered in the link that Zump/Tony posted in post #4. Here it is again, in case you missed it:

 

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Discussion Starter · #12 ·
Okay so today I replaced the the ECT sensor that was the one unplugged and was making the car run with a little misfire and connected it would start run pops misfire to much fuel and die Wich I think is weird why would the vehicle act like that just unplugging the ECT sensor .. question would the car run like that because the seller connected the ignition straight to the relay and I am getting a security light not going away just staying there it has no resistors just checking before I make another step of what the seller said what was the problem he told me today it needs a ECM .. I have already checked the injectors and spark plugs the some coil plugs on top were rusted cleaned them and Same response from the vehicle

Waiting on a box of resistors see what happens
 

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Better put the car on an obd 2 scanner with real time sensor data. See what temp PCM is seeing. A failed coolant temp sensor will often read either 0 degrees, or max degrees. Either of these readings would play hell with PCM giving correct pulse time to injectors.
 

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1994 Firebird Formula 381ci LT1 / TH400+GV O/D
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Just curious - did you test the ECT sensor before replacing it, or did you just decide to replace it? Very easy to test the sensor and the reference voltage supplied by the PCM. Disconnecting the ECT sensor should have set a code (P0118), if the engine was running for more than 15 seconds. You need to start using a scan tool to pull codes (in addition to observing real time data as wisely suggested above by sea dig). Unplugging the sensor provides an open cirucit - infinite resistance, and will display a temperature of MINUS 38-degF. The PCM would react by putting the A/F ratio control in open loop, and heavily enriching the A/F ratio for the false cold condition.

What "resistors" are you going to buy? Why? Is the SECURITY light still "flashing", or is it now on solid when you try to start the engine?

You car has a PCM (Powertrain Control Module), not an ECM (Engine Control Module). It is very unusual for them to fail. The factory service manual (FSM) has a trouble shooting logic diagram for each control system fault, including the ECT. Replacing the PCM is at the very end of the chart.
 

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Discussion Starter · #15 ·
I just replaced it the ECT sensor was cheap . I connected the scanner two different ones and no codes .. the security light is bold doesn't go away but the car starts and starts hesitating mostly all the time really rare that it stays on within minimum hesitation and as I step on the gas it will start to die or die with poping sound from the throttle body and I bought a pack of 760 resistors different values to make the values of the 15 keys
 

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WHAT IS YOUR FUEL PRESSURE?
 
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