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Discussion Starter #1
I have a 1989 with a 302 this morning when I went to start it and it would not start. When I got home I tried again, I can get it to start and run with my foot on the gas peddle but when I release it the engine dies. I tried again and the same thing. The engine runs fine when I keep my foot on the peddle and I can rev it up and release it to around 900 RPM's then it will try and stall until a press the gas some more. It just will not idle. Any suggestions.
 

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OUT OF BUSINESS / M.I.A
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Tank fuel pump?

Secondary rail mounted fuel pump?

Clogged fuel filter(s)?

IAC?

Vacuum leak?



Just don't touch the 'idle adjustment screw' on the throttle body. Don't even talk to it........
 

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vac leak for sure.
 

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I have a 1989 with a 302 this morning when I went to start it and it would not start. When I got home I tried again, I can get it to start and run with my foot on the gas peddle but when I release it the engine dies. I tried again and the same thing. The engine runs fine when I keep my foot on the peddle and I can rev it up and release it to around 900 RPM's then it will try and stall until a press the gas some more. It just will not idle. Any suggestions.
Sounds a lot like the IAC is shot. Try disconnecting the brake booster or something that will cause a major vacuum leak. That should give you an elevated idle. Remove the intake tube that connects to the throttle body. Then with it running, go to the motor and plug the leak. You should hear the IAC open up to compensate for the drop in air volume. If you don't, it's probably stuck or broken.
 

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Discussion Starter #5
When I disconnected the brake booster hose the idle increased some. AFter I disconnected the intake to the throttle body and went to reattach the brake booster hose the engine continues to die. It it starting to seem like it is the IAC, I was wondering if there is some way to test it before I spend the $100 on a new one, and the same problem continues.
 

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search for cleaning out the IAC and you can save some money.

then if that does nto help, pull codes and post them up
 

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X2 for Pulling Codes, www.fordfuelinjection.com for FREE code numbers, code explanations and Test Connector location, you will need either an OBD-I or II Ford Code Reader with diagnostic book, costs $29.99 at O'Reillys currently and worth every penny OR there is a "pulsing technique" using a paper clip....lol lol..


Good Luck ~ :thumbup


Hey RickyB, are you back from the family Road Trip....?
 

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Discussion Starter #9
I went and bought a code reader and have come up with codes 31 and 51. Anyone have suggestions on how to remedy these problems?
 

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There are a number of test procedures in the Haynes Manual to get you started and diagnose the problem, ie: wiggle test, multimeter probe etc. etc. it's a PITA but you don't want to just throw money a problem you know...?

Additional Help source: www.broncolinks.com

Good Luck ~ :thumbup
 

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Discussion Starter #12
Figured out the code 51 and fixed the problem. I have been working on code 31. I have been reading other post and searching for info on this and have come across some people calling the 31 code a EVP issue but when I look in the code book it states that this is for cars only, Trucks 31 code is a EVAP control system below minimum. What is the difference between these and what is the EVAP and where is it located?
 

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penis
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Evap is a line that runs from the tank to a plastic canister located under your washer/coolant res. there will also be a line that run from the engine. It could be anything lose clamp, broken line, cracked canister, damaged lines. Look on you vac diagram under the hood.
 
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