1985 Idle Issues Code 54
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Heel & Toe
Joined: Aug 2015
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1985 Idle Issues Code 54
Hey guys. I just got done installing a new fuel pump and starter and I'm getting a code 54.
Some background on the car- I rebuilt the engine and after driving fine for about 3 months, there were some serious issues with stalling out. So I parked the car, cleaned the TB, verified the EGR to be functional (It holds vacuum and actuates freely) cleaned the intake plenum, replaced the fuel pump, and bypassed the anti-theft in case that was acting up. I am getting spark and fuel.
Right now the car will start, although it has to turn over many, many times before it will fire up. It will then idle steadily for about 5-10 seconds, before it starts surging extremely dramatically, almost loping like it's got a massive cam. Eventually, it dies altogether. If I give it gas, it stays alive. Injector resistance test is within spec (16 exactly) so I'm not worried about that. Noid light also confirms functionality.
Also throwing a Code 54, low fuel pump voltage. I know the fuel pump is fine, it's new.
I'm thinking it may be the relay for the fuel pump, or I may need to set Idle Air and TPS voltage. Or both. Recommendations?
Thanks so much!
Some background on the car- I rebuilt the engine and after driving fine for about 3 months, there were some serious issues with stalling out. So I parked the car, cleaned the TB, verified the EGR to be functional (It holds vacuum and actuates freely) cleaned the intake plenum, replaced the fuel pump, and bypassed the anti-theft in case that was acting up. I am getting spark and fuel.
Right now the car will start, although it has to turn over many, many times before it will fire up. It will then idle steadily for about 5-10 seconds, before it starts surging extremely dramatically, almost loping like it's got a massive cam. Eventually, it dies altogether. If I give it gas, it stays alive. Injector resistance test is within spec (16 exactly) so I'm not worried about that. Noid light also confirms functionality.
Also throwing a Code 54, low fuel pump voltage. I know the fuel pump is fine, it's new.
I'm thinking it may be the relay for the fuel pump, or I may need to set Idle Air and TPS voltage. Or both. Recommendations?
Thanks so much!
Race Director
Joined: Mar 2015
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pull the vacumme line of your fpr and smell for fuel could be the relay or the pump or just a bad connection.
put a fuel pressure gauge on it while running and see what it does.
put a fuel pressure gauge on it while running and see what it does.
Last edited by antfarmer2; Dec 9, 2015 at 12:41 PM.
Thread Starter
Heel & Toe
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Just to be clear is an FPR my fuel pressure regulator? I'm not familiar with that acronym or the location of said part on the car.
EDIT: just looked it up. Vacuum line definitely smells of fuel. Assuming this means the FPR is compromised?
EDIT: just looked it up. Vacuum line definitely smells of fuel. Assuming this means the FPR is compromised?
Last edited by Hobbitrabbit; Dec 9, 2015 at 12:45 PM.
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yes I believe it is on the pass side rear top and round with 6 safety torque screws on it
Last edited by antfarmer2; Dec 9, 2015 at 12:45 PM.
Racer
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From: Pine Ridge FL
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Team Owner
Joined: Jul 2004
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From: Hartford WI
Hey guys. I just got done installing a new fuel pump and starter and I'm getting a code 54.
cleaned the TB,
and bypassed the anti-theft in case that was acting up.
I am getting spark and fuel.
Injector resistance test is within spec (16 exactly) so I'm not worried about that. Noid light also confirms functionality.
Also throwing a Code 54, low fuel pump voltage. I know the fuel pump is fine, it's new.
I'm thinking it may be the relay for the fuel pump, or I may need to set Idle Air and TPS voltage. Or both. Recommendations?
Thanks so much!
cleaned the TB,
and bypassed the anti-theft in case that was acting up.
I am getting spark and fuel.
Injector resistance test is within spec (16 exactly) so I'm not worried about that. Noid light also confirms functionality.
Also throwing a Code 54, low fuel pump voltage. I know the fuel pump is fine, it's new.
I'm thinking it may be the relay for the fuel pump, or I may need to set Idle Air and TPS voltage. Or both. Recommendations?
Thanks so much!
Hope you removed the IAC, IAC housing and cleaned the passages too.
Anti-theft has nothing to do with this. If you put a piece of tape over the pellet, you can turn the key and I can't remember but it either won't crank or it will cut off the injector pulse. I believe it won't crank but that was so long ago I did that.
Did you get a blue flame? Did you check the wires for voltage leaks?
Resistance is meaningless at best, misleading at worst. It doesn't tell you whether there is something obstructing the fuel flow to the pintle. Only bench testing tells you that.
I don't know if the idle was set right but that is another story for a later date.
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Team Owner
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From: Hartford WI
I suppose if the fuel gets into the intake, it can cause issues but I would still check the scanner to see if the pump voltage is wrong. If it is, check with a DVOM at the terminals of the pump.
Race Director
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From: Anaheim CA
The fuel pump voltage has to be less than 2 volts to set error code 54. Basically it means no voltage is going to the pump from the fuel pump relay. Based on your description of your starting problems, it appears that the oil pressure switch is taking over and running the fuel pump.
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The fuel pump voltage has to be less than 2 volts to set error code 54. Basically it means no voltage is going to the pump from the fuel pump relay. Based on your description of your starting problems, it appears that the oil pressure switch is taking over and running the fuel pump.
Team Owner
Joined: Jul 2004
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From: Hartford WI
The fuel pump voltage has to be less than 2 volts to set error code 54. Basically it means no voltage is going to the pump from the fuel pump relay. Based on your description of your starting problems, it appears that the oil pressure switch is taking over and running the fuel pump.
Race Director
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From: Anaheim CA
And the way to test that is? Disconnect the oil pressure switch and see what happens? Since it is a redundant power supply, we could cut the feed and see whether the pump gets the power. However if it is a redundant power supply, would it not give steady power and not affect his running?
If the fuel pump relay is bad (as we suspect from the symptoms), then disconnecting the oil pressure switch will mean the pump will never run.
Team Owner
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From: Hartford WI
I was thinking that the switch being removed would tell us if the entire pump wasn't working. Mauby run straight wire to the pump?
Drifting
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From: Venice Cali.
My loping was cured by a new 02 sensor along with idle adjust, also clean and apply clear dielectric grease to all connectors that go along with the code. Actually every connector in the engine bay probably needs care.
Last edited by xrav22; Dec 11, 2015 at 04:03 AM.
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