2nd Generation Specific (1986-1992) 1986-1992 Discussion including performance modifications and technical support sections.

I need to bypass the fuel relay for the car to stay on.. why??

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Old Mar 9, 2003 | 07:49 PM
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I need to bypass the fuel relay for the car to stay on.. why??

I need to bypass the fuel relay for the car to stay on.. why?? i need some help...
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Old Mar 9, 2003 | 08:14 PM
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First guess would be that it's broken. not sure how much you know about electronics, but a relay is like an electromatic switch. that's why they click, its the solenoid in them moving. If it's not burnt out, then whatever circuit that activates the relay has a problem, and that's gonna be harder to find.
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Old Mar 9, 2003 | 08:28 PM
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Originally posted by yearrgh
First guess would be that it's broken. not sure how much you know about electronics, but a relay is like an electromatic switch. that's why they click, its the solenoid in them moving. If it's not burnt out, then whatever circuit that activates the relay has a problem, and that's gonna be harder to find.
ya it clicks....ok there is a relay under the steering wheel that one clicks..the there is the main relay... that one works of course since the car runs....see the car turns on with me bypassing it. but if i dont itll turn on the shutt off.. i have to turn off and on when bypassing it about every 15 minutes...what do you think it could be.
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Old Mar 9, 2003 | 08:39 PM
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I'm a little confused... Are you saying it will turn on without you bypassing the relay, but will stall quickly. And even if you do bypass the relay, it will die after 15 mins?
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Old Mar 9, 2003 | 09:15 PM
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afm switch i would guess is the problem
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Old Mar 10, 2003 | 01:42 AM
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Are you talking about the yellow plug in the engine bay, or are you bypassing the circuit opening relay under the dash? If it's the plug, you're actually bypassing the safety switch in the airflow meter. If the switch isn't closing when the AFM's flap opens, you'll probably need to replace the AFM. If you're actually bypassing the relay, it could be the switch or the relay. Check the FSM for details on testing them both, then go to a wrecker and find a replacement. Either way, this is an important safety feature, so don't just leave it bypassed.
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Old Mar 10, 2003 | 07:29 AM
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Originally posted by NZConvertible
Are you talking about the yellow plug in the engine bay, or are you bypassing the circuit opening relay under the dash? If it's the plug, you're actually bypassing the safety switch in the airflow meter. If the switch isn't closing when the AFM's flap opens, you'll probably need to replace the AFM. If you're actually bypassing the relay, it could be the switch or the relay. Check the FSM for details on testing them both, then go to a wrecker and find a replacement. Either way, this is an important safety feature, so don't just leave it bypassed.
ok ok there is a plug that is between the air flow and the engine... i just plugged a connector thats going no where...i opened the circuit opening relay and when i have the bypass on.. it leaves the circuit opening relay on at all time...so sould i replace the afm and wich relay?
the car works fine with the bypass for like 15-20 minutes... then it srtuggles and i just shutt it off and on and its fine again.. i had it like this for like 2 months..
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Old Mar 10, 2003 | 03:12 PM
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Old Mar 10, 2003 | 08:55 PM
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Old Mar 10, 2003 | 11:07 PM
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Originally posted by Quenepahead_racing
ok ok there is a plug that is between the air flow and the engine... i just plugged a connector thats going no where...i opened the circuit opening relay and when i have the bypass on.. it leaves the circuit opening relay on at all time...
Dude you're confusing me! Are you putting a jumper wire on the yellow plug beside the RHS shock tower in the engine bay OR are you doing something with the circuit opening relay under the dash?
Either way, download the EFI chapter of the FSM and read the sections on how to test the AFM and the relay to figure out which one is the problem. It's very simple.
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Old Mar 11, 2003 | 08:25 AM
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yes im jumping the yellow plug. where can i download the "download the EFI chapter of the FSM" from???? Let me know. Thanks
QHR
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Old Mar 11, 2003 | 07:49 PM
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Old Mar 11, 2003 | 09:07 PM
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If your Air Flow Meter Is the culprit, after confirming that you're actually bypassing the safety switch, It's likely that a colder solder joint has broken away. It will require a resolder. No big deal. Been there.
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Old Mar 12, 2003 | 01:39 AM
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Originally posted by Quenepahead_racing
yes im jumping the yellow plug.
Ah, now we're getting somewhere. However you failed to mention earlier that you have an S5. We all assumed you had an S4. S4's have the safety switch in the AFM, whereas S5's do this via the ECU. This makes the problem harder to track. Do the check of the circuit opening relay on page F2-53 of the FSM and let us know.
where can i download the "download the EFI chapter of the FSM" from?
www.fc3s.org or www.iluvmyrx7.com

Last edited by NZConvertible; Mar 12, 2003 at 01:41 AM.
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Old Mar 13, 2003 | 11:38 AM
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i checked the that relay the c. opening relay.. i took out the top cover and disc the jump that i was doing with the yellow plug..the relay will close then it wil open and the car will turn off.. then when i jump the yellow plug it will stay on...
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Old Mar 13, 2003 | 06:12 PM
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ok i just changed the air flow meter.... SAME PROBLEM!!!!!! question.....what is the job of the circuit opening relay???? does it have to stay always on?
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Old Mar 14, 2003 | 07:28 AM
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what is the job of the circuit opening relay????
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Old Mar 14, 2003 | 11:24 AM
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To kill the fuel pump when you have a wreck.

If you have a series five car, Pin 3K has to put a ground on the Circuit Opening Relay when the afm is sensing the engine is running. Put a meter on 3K, turn the key to ON, shove the afm's cone in an aft position, and see if you get a ground on 3K. If its putting out a ground signal, the relay should pull in, and KEEP the fuel pump running.

When you HOLD the key to START, you make a circuit to the fuel pump, but ONLY if the key is held to START. If the engine starts, then the cone in the afm lets the ECU know the engine is now running, and puts a permanent ground on the Circuit Opening Relay to keep the fuel pump running even when you let go of the key and are not in START anymore.

Last edited by HAILERS; Mar 14, 2003 at 11:35 AM.
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Old Mar 14, 2003 | 12:42 PM
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OKOKOK so that means that the Circuit Opening Relay should always stay on. right? as long as the car is on.. the relay should not turn off after the car starts. right.
see, like i said i open the top cover of the relay...then i turned on the car.. the relay turned on then it cut off....so your saying that the relay should stay on when the car is on. right? so then the relay is bad..right?
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Old Mar 14, 2003 | 02:03 PM
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The relay should be pulled in:
1. When the key is HELD to START.
2. When the engine is runnig.

The relay is NOT pulled in:
1. When the key is to any other position other than START and the engine is not running.

When the engine is running, you should have a ground put on the relay by pin 3K of the ECU. The ground pulls the relay in. Assuming that the 12v is already there on the coil, which it probably is.

Last edited by HAILERS; Mar 14, 2003 at 02:14 PM.
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Old Mar 14, 2003 | 04:31 PM
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thanks alot....let me replace the relay. ill let you know if that fixs the problem...
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Old Mar 16, 2003 | 12:53 AM
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I'd look for a ground signal on pin 3K before I'd shell out bucks for a relay. You sound like a aircraft technician. Always changing things , swapping things, r squaring things.
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