gas pump dimmer for security system, how
Printed From: the12volt.com
Forum Name: Car Security and Convenience
Forum Discription: Car Alarms, Keyless Entries, Remote Starters, Immobilizer Bypasses, Sensors, Door Locks, Window Modules, Heated Mirrors, Heated Seats, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=80299
Printed Date: May 07, 2025 at 12:13 PM
Topic: gas pump dimmer for security system, how
Posted By: luismuro
Subject: gas pump dimmer for security system, how
Date Posted: July 14, 2006 at 3:50 PM
Hi guys, I'm looking for your help or info abuot some devices which can help me reduce the volts flow to the gas pump in order to get it stopped, my idea is as follows: I'm in Mexico and I'm to get installed a GPS/GPRS tracking device in a 2006 Honda Accord, the company's device offers a negative pulse to get a power cut to the gas pump throug a relay in order to get it stopped inmediatly, my question to the dealer was if there is any way to gradually decrease the voltage to the gas pump (witin 30 sec-1 min) to get a chance to pullover; and after the event the device be able to reset itself as soon as the system gets the command to do so; (just as if the car was running out of gas), for my own confort just in case the device fails and cuts the gas power as I'm on the highway so we can reduce a chance of an accident. any comments or sugestions greatly appreciated. Thanks in advance
Replies:
Posted By: luismuro
Date Posted: July 14, 2006 at 5:31 PM
I do know the gas pump it's submerged into the gas, and because of that it's being lubbed all the time; the purpose is not letting the pump to run dry but as I mentioned before, gradually reduce the voltage which the pump receives(I'm thinking to 6V or less), it's just a security measure, just in case the car gets stolen so the tracking company does a remote stop and it gets accomplished in a gradual, safer way.
Posted By: luismuro
Date Posted: July 14, 2006 at 6:59 PM
As I see neither way is safer, to cut current or reduce it anyway a damage can be done, I came with the question because the device's dealer told me not to cut current to ignition system beceuse of the computers, but safer doing the gas pump, as you mention the fuel pressure is something I didn't realize and is a good point, I'll be looking forward for more reliable solutions; may be an RPM's limitter or so?
Posted By: KPierson
Date Posted: July 15, 2006 at 8:57 AM
I think you're overlooking too many factors here. What kind of fuel pressure will your pump provide at 6volts? Its possible the pump won't run at all. If it does run, and you do not have enough pressure built up your injectors won't inject enough gas to keep combustion going (I think 22:1A/F ratio is about the leanest you can run). Running A/Fs that high for extended periods of time can really tear up some pistons, as the fuel is designed to cool the tops of them. However, your newer Accord most likely uses some sort of O2 sensors to automatically adjust injector pulse width if the car starts to run lean, so its possible even at 6vdc the car will still run half way decent, assuming you have some sort of pressure still backing the injectors. If its going to be a gradual, but still somewhat short cut off, I would look in to cutting either one or two injectors or one or two coils (or even both an injector and a coil). You don't want to run entended periods with spark but no gas in the chamber, and you also don't want to run extended periods with gas but no spark (hence why it may be better to kill fuel and spark in one cylinder). This should greatly reduce the way the car rides, while giving them time to pull over, and without risking permanent damage to the motor. Seems like a lot of work to me though just to safely pull over the guy who stole your transponder based vehicle.... ------------- Kevin Pierson
Posted By: luismuro
Date Posted: July 15, 2006 at 2:29 PM
I think I'll have to go over tech data on fuel and ignition systems, (over the web; car deales in Mexico won't provide that kind info) and try to figure out someway to make the car to automatically reduce speed, RPM's or something within 30-60 seconds. I'll post some comments later.
Posted By: KPierson
Date Posted: July 15, 2006 at 4:53 PM
Do some research and try to find if your car has a 'limp mode'. Many new cars have this 'feature' that is enabled if certain events occur. Limp mode will prevent the car from revving past a certain RPM and will make the car very hard to drive. Its designed to allow the driver to get the car to the dealership without risking damaging the motor. You may be able to force the car in to limp mode by disconnecting the MAF with a relay or something like that. Its worth looking in to.
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Kevin Pierson
Posted By: KPierson
Date Posted: July 16, 2006 at 8:56 AM
Who doesn't have an OBDII reader in their tool box these days??? If you don't have one, most Autozones will read and reset codes for you. If you don't want to go to Autozone you can just unplug the battery over night and it should clear it without any problems. Anyway, if the car is stolen it will most likely be turned in to insurance for repairs so I don't think a CEL will be a big deal. ------------- Kevin Pierson
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