92 camaro 350 tbi no injector pulse until battery is almost dead
12-03-2016, 02:04 PM
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92 camaro 350 tbi no injector pulse until battery is almost dead
Hey everyone. New here but I recently picked up this 92 camaro rd with a 350 tbi in it. I got it in trade not running but it cranked and would fire if I dump fuel in the throttle body. I've been messing with it the past couple weeks trying to figure out the problem but after cranking it over many times I've drained the battery twice now and each time right when it's almost to the point where the battery has not enough juice to crank the motor anymore the injectors start spraying. I have a code 53 engine light on and I recently thought that was the vats system so I bypassed it using the correct resistors but that didn't fix it. Just looking for some help an advice. Thanks
12-03-2016, 03:26 PM
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Re: 92 camaro 350 tbi no injector pulse until battery is almost dead
Check/replace the ICM (ignition control module) which is inside the distributor. If the ECM does not get a pulse from the distributor (DRP), it will not pulse the injectors. For complete troubleshooting, go to Chevythunder.com. HTH!
12-03-2016, 08:25 PM
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Re: 92 camaro 350 tbi no injector pulse until battery is almost dead
Code 53 is a system over-voltage. This usually indicates a bad voltage regulator in the alternator but as your engine is not running, I would have a hard time believing that code. It may have been stored for a while from the previous owner. Pull the negative battery cable and recharge your battery. Once the battery is recharged, re-connect the negative cable and see if the code comes back. Use a volt meter to check your battery voltage. Code 53 is set if the ECM sees voltage higher than 17 volts for more than 2 seconds. This information is taken from Chevythunders troubleshooting codes guide. There are complete ignition system troubleshooting guides also. HTH!
12-03-2016, 08:31 PM
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Re: 92 camaro 350 tbi no injector pulse until battery is almost dead
It has a brand new battery in it. It's charging now because I ran it dead trying to start it. I used a noid light to test that the injectors were getting power and it was but the light would only come on once every couple seconds of cranking. Also the previous owner told me that the car was originally a 305. I'm starting to think it's a bad ecm but I just don't know too much about these cars.
12-03-2016, 08:56 PM
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Re: 92 camaro 350 tbi no injector pulse until battery is almost dead
Unfortunately, without doing some extensive troubleshooting, you will be throwing parts at it in hopes of fixing the problem. Go to Chevythunder.com and do some reading. You can get very familiar with these fuel injection systems fairly quickly by reading the various sections there. There are step by step flow charts to help diagnose many of the different systems that make up the fuel injection system as a whole. With this being a somewhat intermittent problem, it may be harder to diagnose. I think the TBI system fires the two injectors alternating between the two once every revolution of the engine so the noid light on one injector would only flash once every two engine revolutions. If this is the case, you should check your fuel pressure. You should have about 13 PSI while cranking. Check to be sure you have good fuel pressure. HTH!
12-03-2016, 09:03 PM
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Re: 92 camaro 350 tbi no injector pulse until battery is almost dead
I haven't put a fuel pressure test gauge on it but I'm pretty sure I'm getting enough fuel. I took off one of the fuel lines to the throttle body and turned the key on and fuel came flowing out. And I also used a 9 volt battery to make sure injectors were good and they sprayed fuel perfectly fine when I used the 9v battery
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12-04-2016, 08:12 AM
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Re: 92 camaro 350 tbi no injector pulse until battery is almost dead
In TBI vehicles code 53 is VATs. Clear the codes and see if it comes back. If it does then I'd say the VATs module is bad (you already did the resistor trick). There are a number of ways to get around this, but the easiest is likely one of the 25-dollar VATs replication modules.
RBob.
RBob.
12-05-2016, 12:59 PM
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Re: 92 camaro 350 tbi no injector pulse until battery is almost dead
I disconnected the battery but I still have the code 53. Is the code 53 vats or high voltage? Whatever it is im sure it is the problem.
12-05-2016, 01:22 PM
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Re: 92 camaro 350 tbi no injector pulse until battery is almost dead
Vats will be 2.5-5v to B6 on the ecm or a hz signal 30 or 50hz at 50/60%.
http://m.ebay.com/itm/GM-VATS-or-PASSkey-II-Bypass-Module-For-LS1-and-LT1-/281813159375?hash=item419d5f8dcf%3Ag%3AsysAAOSwN81WEYiu&_trkparms=pageci%253A20189c0d-bb20-11e6-8513-74dbd180c2a4%257Cparentrq%253Ad06fbbb81580a34fcc58f1a8ffe27235%257Ciid%253A3
http://m.ebay.com/itm/GM-VATS-or-PASSkey-II-Bypass-Module-For-LS1-and-LT1-/281813159375?hash=item419d5f8dcf%3Ag%3AsysAAOSwN81WEYiu&_trkparms=pageci%253A20189c0d-bb20-11e6-8513-74dbd180c2a4%257Cparentrq%253Ad06fbbb81580a34fcc58f1a8ffe27235%257Ciid%253A3
12-05-2016, 01:58 PM
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Re: 92 camaro 350 tbi no injector pulse until battery is almost dead
That's one way of doing it (the modulator), the other is to have it reprogrammed out of the prom.
The prom should have been changed to a caprice code anlu or atjp which did not have vats enabled.
The prom should have been changed to a caprice code anlu or atjp which did not have vats enabled.
12-05-2016, 02:41 PM
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Re: 92 camaro 350 tbi no injector pulse until battery is almost dead
As far as I know I think it's still the 305 ecm. Am I going to have to change that or will I be ok.
12-05-2016, 03:17 PM
#16
Re: 92 camaro 350 tbi no injector pulse until battery is almost dead
There are a lot of people who don't change the ecm calibration and injectors during a 305-350 engine swap. It would be a good idea todo so you can help insure the engine isn't running too lean.
http://m.ebay.com/itm/NEW-STANDARD-SMP-TBI-FUEL-INJECTOR-BUICK-CADILLAC-CHEVROLET-GMC-OLDSMOBILE-TJ7-/381567259069?hash=item58d72e51bd%3Ag%3Ap9QAAOxyYANTamcQ&_trkparms=pageci%253Aa57369d5-bb2f-11e6-a083-74dbd180e05b%257Cparentrq%253Ad0d573811580a6a5ca2512a7ffe3496b%257Ciid%253A10
http://m.ebay.com/itm/NEW-STANDARD-SMP-TBI-FUEL-INJECTOR-BUICK-CADILLAC-CHEVROLET-GMC-OLDSMOBILE-TJ7-/381567259069?hash=item58d72e51bd%3Ag%3Ap9QAAOxyYANTamcQ&_trkparms=pageci%253Aa57369d5-bb2f-11e6-a083-74dbd180e05b%257Cparentrq%253Ad0d573811580a6a5ca2512a7ffe3496b%257Ciid%253A10
12-05-2016, 04:09 PM
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Re: 92 camaro 350 tbi no injector pulse until battery is almost dead
But it should still run right? My main thing is I want to get it running first before I start throwing money at it.
12-05-2016, 05:42 PM
#21
Re: 92 camaro 350 tbi no injector pulse until battery is almost dead
Without the prom in the ecm the ecm doesn't expect the vats signal and should run the engine in a limp home mode.
I don't know what to recommend about a hz modulator or with just going with a 350 prom.
I don't know what to recommend about a hz modulator or with just going with a 350 prom.
12-05-2016, 06:03 PM
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Re: 92 camaro 350 tbi no injector pulse until battery is almost dead
Ok I will give that a try when I get some time to mess with it. And is there anyway in telling what ecm is in there? And if I can get it to run without the prom I will probably just buy the right one that goes in there if I can find it.
12-05-2016, 06:10 PM
#23
Re: 92 camaro 350 tbi no injector pulse until battery is almost dead
The prom has a code on it (broadcast code).
http://www.3rdgenformula.com/92/promcodes.htm
I do have a few of the 350 automatic proms.
https://www.thirdgen.org/forums/engi...-350-prom.html
http://www.3rdgenformula.com/92/promcodes.htm
I do have a few of the 350 automatic proms.
https://www.thirdgen.org/forums/engi...-350-prom.html
12-05-2016, 06:51 PM
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Re: 92 camaro 350 tbi no injector pulse until battery is almost dead
Awesome. Hopefully I'll have some time tomorrow to tinker with it and I'll get back to you on here. I hope she starts. It's just weird to me that whenever the battery is almost dead the injectors start spraying like normal.
12-05-2016, 08:23 PM
#25
Re: 92 camaro 350 tbi no injector pulse until battery is almost dead
I bet Robb would know about the injectors spraying at low voltage. The ecm maybe going into a limp home mode at low voltage in not sure if that's possiable. The odd thing is vats disables injector pulse. The injector pulse changes off battery voltage but very odd they can even pulse with vats not functioning properly.
12-05-2016, 08:36 PM
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Re: 92 camaro 350 tbi no injector pulse until battery is almost dead
Yeah it stumped me. So I came here in hopes of figuring it out. Seems like I'm starting to get somewhere. I think the previous owner was dealing with the same thing and gave up. Cuz currently the have bypassed the starter relay and I have to touch two wires together to start it. Ones a hot which I don't know where it goes and the other is the pink one that goes to starter.
12-07-2016, 02:53 AM
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Re: 92 camaro 350 tbi no injector pulse until battery is almost dead
I would trust Rbob and Tuned on this, Code 53 for TBI is probably VATS. I assumed that the codes for TPI and TBI would be the same but I guess not! You know what they say about assuming things, LOL!
12-08-2016, 02:20 PM
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Re: 92 camaro 350 tbi no injector pulse until battery is almost dead
Well I had some time today and I took the prom out and everything seemed to work. Injectors sprayed and everything. Was trying to keep it running but it backfired and about caught my beard on fire 😂 It might be out of time. Well if I can buy that prom for the 350 and auto trans that would be awesome. I think that would be the best route to go.