Need Help ASAP, Computer turns on Ocasionaly...

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May 17, 2012 | 09:37 AM
  #1  
I got a 1988 Camaro Iroc-Z with a 350 TPI.
Problem is that when i turn the Key to On, the SES light doesnt turn on, and i cant hear the Fuel Pump... so i know that the Computer doesnt turn on and cant figure out why... i need to fix this Asap... any Ideas??? Google was not of any help... or im just not searching correctly
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May 17, 2012 | 12:50 PM
  #2  
Re: Need Help ASAP, Computer turns on Ocasionaly...
Ok i just checked the Pink wire under the stering column called a garage and they told me that if this wire had no feed then it would be a wire problem if it as power then my ECU/ECM would be dead... any1 as any knowledge about this?

Pink wire Reads 1.4volts called to near by garage and they cant tell me the correct reading...

if anyone as info id apreciate it thanks!!
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May 17, 2012 | 12:57 PM
  #3  
Re: Need Help ASAP, Computer turns on Ocasionaly...
B1 orange at the ecm is the 12v supply, a6 pink/blk in the switched 12v to the ecm. You might check your ecm grounds on the back of the lh cylinder head.
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May 17, 2012 | 12:58 PM
  #4  
Re: Need Help ASAP, Computer turns on Ocasionaly...
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May 17, 2012 | 01:01 PM
  #5  
Re: Need Help ASAP, Computer turns on Ocasionaly...
the back of the Lh cylinder head? sorry im not to familiar with all of the part of this car
but im getting it preety quick, theres this square box at my feet in the fire wall with lots of plugins is this where i should check for the B1 and the A6 cables?

Edit:

Ok found the B1 and A6 tested them and heres is what the reading gave me
B1:2.5V(Ignition at On position)
B1:2.4V(Ignition at Off position)
A6:12V(Iginition at On position)
a6:0V(ignition at Off position)
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May 17, 2012 | 01:14 PM
  #6  
Re: Need Help ASAP, Computer turns on Ocasionaly...
the connections listed above are at the ecm. Ecm grounds are in your engine bay on the rear of the right hand side head. sorry I said left.
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May 17, 2012 | 01:32 PM
  #7  
Re: Need Help ASAP, Computer turns on Ocasionaly...
i tested A12 & D1 for Conection with a continuity test and they are good so ground are good for sure, im starting to think that my ECM is faulty...
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May 17, 2012 | 01:35 PM
  #8  
Re: Need Help ASAP, Computer turns on Ocasionaly...
ok i found this Chart: http://www.chevythunder.com/fuel%20i...%20pinouts.htm

so im guessing im having a faulty conection on B1? or is this chart not acurate?
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May 17, 2012 | 02:05 PM
  #9  
Re: Need Help ASAP, Computer turns on Ocasionaly...


looks like somewhere b1 has corrosion at a connection it startes off at the fuse box and it looks like it get taped onto at the oil pressure switch and the mass burn off relay and mass air flow relay. these are in the engine compartment drivers side next too the master cylinder.
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May 17, 2012 | 07:22 PM
  #10  
Re: Need Help ASAP, Computer turns on Ocasionaly...
Ok i Solved the problem, I By passed my FUel pump Relay since i knew i had spark from the ECU/ECM, my car now starts with better idle and the pump seems to run much better too, so i guess ill have to buy my self a new Fuel Relay, is this by pass harmfull to the pump if i make sure to operate my switch correctly?
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May 17, 2012 | 08:59 PM
  #11  
Re: Need Help ASAP, Computer turns on Ocasionaly...
I would install a new relay I think 85-87 us a acdelco 212-307, I like the newer relays better like acdelco 15-8240 pigtail PT1115
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May 18, 2012 | 10:04 AM
  #12  
Re: Need Help ASAP, Computer turns on Ocasionaly...
i plan on placing a new relay but for now is this fix harmfull to the operation of the car?
i noticed a better idle since i installed this by pass
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May 18, 2012 | 11:32 AM
  #13  
Re: Need Help ASAP, Computer turns on Ocasionaly...
You didn't mention if your by-pass is to switched on power-I.E. no power to the fuel pump unless the ignition key is on. You definitely don't want the pump running all of the time, only when the ignition is turned on. Also, you want to replace the relay asap. Anytime the fuel pump is running, like any other mechanical device it is wearing. If you only run it when you start the car and have the engine running, then what you are doing is no different than what the fuel pump relay does. Also make sure that the pump is not turned on with the key switch in the accessory position. If you turn the key to accessory to listen to the radio while waiting for someone or something, you don't want the fuel pump running. It won't hurt to have the pump running, it just circulates fuel back to the tank when the engine is not running, but you don't want to wear it out.
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May 18, 2012 | 01:08 PM
  #14  
Re: Need Help ASAP, Computer turns on Ocasionaly...
i Installed 2 switch ill show you a quick diagram of what i did when i get to my laptop but my switch is connected directly on the Positive terminal of the batery, and i only turn it on for the engine to start and off after i turn off the engineName:  FuelRelayFuelPumpByPass.jpg
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May 18, 2012 | 03:34 PM
  #15  
Re: Need Help ASAP, Computer turns on Ocasionaly...
you might want to fuse the power supply. I would really replace the relay there not that much. I relays purpose is so a small current can control a large current draw.
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May 19, 2012 | 09:25 AM
  #16  
Re: Need Help ASAP, Computer turns on Ocasionaly...
The problem with your by pass is there is no fuse protection. If a wire should chafe on the body and short to ground or the fuel pump shorts out, it could stat a fire that would burn your car to the ground! If you should get a fuel leak in the engine compartment, you would need to remember to shut off the switch before exiting the car. It would not be enough to just shut off the key.
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Jun 20, 2012 | 09:36 PM
  #17  
Re: Need Help ASAP, Computer turns on Ocasionaly...
Quote: ok i found this Chart: http://www.chevythunder.com/fuel%20i...%20pinouts.htm

so im guessing im having a faulty conection on B1? or is this chart not acurate?


Is there a site that shows this exact same thing for a n 86 firebird 2.8v6 MPFI ???? I am having these same issues but this link has for the 3 connectors on ecm my firebird has 2
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Jun 20, 2012 | 10:07 PM
  #18  
Re: Need Help ASAP, Computer turns on Ocasionaly...
Quote: Is there a site that shows this exact same thing for a n 86 firebird 2.8v6 MPFI ???? I am having these same issues but this link has for the 3 connectors on ecm my firebird has 2
1227302 ?

https://www.thirdgen.org/forums/dfi-...730-749-a.html
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Jun 24, 2012 | 10:04 AM
  #19  
Re: Need Help ASAP, Computer turns on Ocasionaly...
When u first turn the key to the on position, your SES should flash once very quickly and turn solid. You should also hear the fuel pump turn on. Now turn the key off and turn it on again. You may not hear the pump come on. This is normal. Turn the key off and wait ten seconds and try again. You should now hear the pump.
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