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New EFI ran great for 20 minutes today, turned off for 10 minutes and problems.

rjrobin2002

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I finished my EFI swap a month ago and have been finishing the brakes, hydroboost and suspension since then. It fired right up and ran perfect even though I had not installed my o2 sensors a month ago. I have a 96 Explorer motor with RJM harness and mustang distributor/coil/computer. I got codes 81, 82, 85, 84 before initial start up last month and it ran great.

I still have not completed my exhaust and yesterday I went to start it and it will fire up for about 1/2 a sec and dies, it does not change if I give it the gas.
I checked fuel pressure and got 40 psi and checked codes and got 81, 82, 85, and 84. What next?
 
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rjrobin2002

rjrobin2002

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If the IAB was stuck closed, would it not crank and throw no codes? It would not crank when I gave it gas either though.
 
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rjrobin2002

rjrobin2002

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I did not have time to check, just got my codes and fuel pressure and figured a code or fuel pressure issue would point me the right disrection. It fires up for about 1/2 second, so I know it has spark for that 1/2 second.
 
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rjrobin2002

rjrobin2002

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40 psi at rail and the pump turns on for about 2 seconds when the key is turned on. Fuel pressure holds at 40 for a while after turning off.
 

DFP1129

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I'm following this one too- we just finished the install and have the exact same codes... we havent started the motor yet-- just doing the KOEO test to see what it showed us..

im learning as i go--sooo...

this is what they're described as..

81- secondary Air diverter
82- Secondary Air Bypass
85- CANP Circuit failure
84- EGR Vacuum regulator.. EVR

David
 
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rjrobin2002

rjrobin2002

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Those are the normal codes we are suppose to get due to not running the emissions.
 

needabronco

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I'd suggest you go back and check all of your codes, maybe check to see if anything was unplugged when you were doing any other work.

After that my first guess would be a bad TFI module. I've had a couple do wierd things right before they crap out on you. The parts store TFI's are pretty bad as far as reliability, I've had them last a couple of years to a few days!
 

DFP1129

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@ rjrobin- cool and thanks.. so im firing it up tomorrow and will go from there.. good to know also about the TFI as well..
 
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rjrobin2002

rjrobin2002

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I have 40 psi when the key turns on and after it dies. The codes would not tell me if something was unplugged?
I have an extra distributor and TFI I will put on Thur when I am off. How do you test them?
 

Viperwolf1

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I have 40 psi when the key turns on and after it dies. The codes would not tell me if something was unplugged?
I have an extra distributor and TFI I will put on Thur when I am off. How do you test them?

KOEO codes should tell you if something important is unplugged. That's its function. KOER codes tell you if the sensors/actuators operate within their parameters.

How soon after does the fuel pressure die? You shouldn't be able to see it drop immediately. Also see if fuel pump is still running after startup. You can ground a pin in the diag connector to make the pump run continously.

I seem to recall some testing procedures over on the rangerstation.com. Here it is: http://www.therangerstation.com/tech_library/TFI_Diagnostic.html
 
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rjrobin2002

rjrobin2002

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Fuel pressure never dies. It shoots up to 40 with the turn of the key and will stay up for hours after turning it off.

I am thinking it is a spark issue as it fires up for 1/2 second and them does not act like it has any spark. I have an extra TFI I am going to try tomorrow.
 
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rjrobin2002

rjrobin2002

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I just went out to the shop and it cranked up and was running good for the 10 seconds I had it on, then I killed it to run codes. I am going to install my o2 sensors tomorrow. I ran codes after it cranked and got the same 81, 82, 85, and 84. I dont understand, but maybe it will run good forever.
 
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rjrobin2002

rjrobin2002

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I installed my exhaust and got my o2 sensors installed. It cranked right up and I let it idle for about 20 minutes and it ran smoother and smoother the longer it ran, which is what I was told it will do as the computer adjust. I occasionaly gave it some gas and would let it run at 2000 rpm for about 20 seconds and let it return to idle. It was doing great. I went inside for 10 minutes after turning it off, went to crank it and it has returned to cranks up for about 1 second and dies. I have not got codes yet, but what is your sugestion for part problems? TFI?
 
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rjrobin2002

rjrobin2002

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Any tips while I am sitting at work thinking about my Bronco?
 

ransil

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Appears to be a closed loop issue , eng temp above 170 when the computer is looking for sensor input.

How did you wire pin 30 on the computer?
What is your computers code?

It the computer 5 volt trace is burnt I would expect it to throw a list of codes needing a 5 volt reference.

Sent from my Galaxy Nexus using Tapatalk 2
 
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