I hope I get this in the correct place, as I'm just an old gear head and not a computer user. My son and I have a 89 pontiac firebird project car with a 305 throttle body injection. The car starts instantly, but then immediately dies. If you pump the accelerator after it starts you can keep it running, but can't maintain a constant idle and it backfires through tailpipe or pops through the tbi occasionally. The error code is 53 "High voltage at battery OR High voltage at exhaust gas recirculation valve OR Voltage reference error OR Problem at vehicle anti-theft system". My son thought it might be a VATS issue even though it starts as he had trouble with VATS before and had to replaced the ignition cylinder a few years ago. He purchased and installed a bypass module from Rocky Mountain something, which now allows the car to start without a special key. The car however still has the same symptoms and still generates error 53. We checked the voltage at the battery and it is fine. We don't know what the voltage is supposed to be at the EGR valve, and neither of us knows what a "voltage reference error" is. I hate to start throwing more money at this thing, guessing which part to replace to fix the error. The folks that sold my son the bypass kit suggest the ECM is bad, but I'm afraid if we replace it we will just find out that it is something else. ANY help would be greatly appreciated!

 

sounds like a alternator voltage regulator issue.

 

Error Code 53 relates to overcharging. Where the ECM has seen over-voltage greater than 16.9v for more than 10 seconds. This would definitely give the wrong readings to the ECM as the basic reference voltage s only 5.0v. and could possibly be your only problem. Should be easy enough to confirm. As far as the VATS giving you troubles. The vats sys. actually only kills the fuel pump if it doesn't recognize the key in the ignition. Good Luck

 

the vats will not kill fuel pump it will cut injector pulse though

 

First, thanks to everyone for the replies!

The car won't run for 10 seconds, after the initial start it dies within a second unless you pump the accelerator then you can keep it running. While my son pumped the accelerator I checked the voltage at the battery and it was ~14.8. To rule out the altenator we disconnected it, but the car still fails to run (voltage at battery was ~12.8). I checked the voltage at the power wire to the ECM according to the VATS bypass instructions (pink w/ black stripe) and it is the same as at the battery when key is on / car is running. I am guessing this isn't the reference voltage though based on the post that the reference voltage is only 5v. How do you check the reference voltage?

The VATS bypass has 2 parts from what I can tell, one is to allow the car to crank and the other to provide the correct signal for the ECM to pulse the injectors. I obviously know the crank part works, as if I remove the jumper it will not crank. I assume since it starts briefly, and will continue to run as long as the accelerator is pumped, indicates the injectors are in fact pulsing (son said timing light shined into the tbi confirmed this). The car "runs" the same with 100% factory vats setup or with the VATS bypass installed. As a test, I connected the crank jumper wire, but didn't connect the ECM wire on the bypass unit which results in the car cranking but the injectors do not pulse. This is why I think I can rule out the VATS system as the issue.

Is the initial start based on a pre programed fuel map? Would this bad reference voltage or EGR voltage cause it to get the mixture wrong after the intial start and the pumping of the accelerator is working to keep it running as the result in an extra call for fuel from a change in the throttle position sensor?

 

From what I just read you say if you keep the throttle partially open it continues to run. But wont idle,just shuts off. Have you checked the idle air control pintle for carbon build up? Also there's an idle bypass in the throttle body for minimum air flow. and the throttle plates also build carbon and also can have an effect. But from what your describeing it could be there's not enough air to keep it going at idle. just a thought

 

If I try to hold the throttle open to any constant position the car dies just as if it wasn't depressed, the only way to keep it running is to pump it at a fairly rapid pace.

 

Distributor was bad, car runs great now. Thanks for the posts.