NEED HELP!!! ANYONE???
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NEED HELP!!! ANYONE???
I'll try this again....got no replies last time. '94 F-150, 302: Starts great 1st thing in the morning, takes 5-10 secs. to fire up the rest of the day. Runs great otherwise. I've ran a few tests: Fuel pressure w/key on/engine off is 40 (spec. is 35-45), fuel pressure with engine at idle is 30 (spec. is 35-45). Turn off truck (and remove key) and pressure climbs to 40 and stays there for quite some time. This holds true for both tanks. Just replaced the fuel pressure regulator yesterday and no change. Replaced filter a week ago. Apparently, Ford had issues with dual tank models for a while. I dunno if mine was one of those. I want this problem fixed...it's a nice truck, but people look at you funny when it doesn't want to start (don't really care about them as much...I just like things to be right!) Help, please, anyone??? Subford, you seem to know your ****...any ideas?
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From: Easton,Ks
Heat from engine is raising the fuel pressure. No vacuum with the engine off so the FPR will not bypass any fuel back to the tank until it reaches 45 PSI.
May have a bad ECT or ACT sensor causing it to crank longer to start.
Have you pull the codes to see what they say?
May have a bad ECT or ACT sensor causing it to crank longer to start.
Have you pull the codes to see what they say?
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ECT is good...tested a couple days ago (resistance high when cold, lower when warm) What/where is the ACT? Had it plugged in a couple days ago and got no codes-
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Yes, dual tanks. Mileage is about 15. Weird, I know! It just runs too good once it's fired up for it to be anything major. I'm hoping that it's nothing to do with fuel pumps. I don't really wanna pull the tanks. That wouldn't make sense to me either because has the same symptoms on both tanks-
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From: Easton,Ks
The fuel system sounds like it is OK.
The ACT (Air Charge Temp) or IAT (Intake Air Temp.) sensor is located as in the photo below.
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The ACT (Air Charge Temp) or IAT (Intake Air Temp.) sensor is located as in the photo below.
/
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Subford, first off, thanks for your help so far...this is all new to me. I know I said that I got no codes, but I think the Auto Zone guy just didn't know what he was doing (he didn't wait long enough for the continuous codes to come up). I did a self test yesterday with a multimeter and jumper wire per Haynes. It was a bit confusing to me, and I'm not 100% that the results are correct. Here's what I found tho...got code 542 (should be sumthin with the fuel pump. I see you've dealt with this one before...read an old thread). Wierd tho, code 54 is for the ACT/IAT. Maybe I read it wrong? Haven't done a running test yet either. Also, parts store had the ACT in stock, but they showed me the one that screws into the intake, not the snap in one like you show (and like I have). Should I just change the friggen thing for 20 bucks? Still doesn't explain low fuel pressure either (30 psi when running and 40 with key on...spec. is 35-45 either way).
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From: Easton,Ks
The 542 code is normal if you grounded pin #6 of the EEC Self-Test connector to do a fuel system pressure check.
Moving the key on and off will not tell you much on a fuel pressure test.
With the engine not running and pin #6 grounded with the key on you should get about 45 PSI.
Idle should be from about 32-34 PSI and WOT should go to 40-42 PSI.
Your fuel pressure gauge may be off a little but with 30 PSI at idle you know you have great vacuum anyway.
All of your codes will have three numbers in them, unless you have a manual transmission.
More information on self-test go to:
Ford Fuel Injection How To Run a Self-Test
The older trucks used a screw in ACT in the intake but 1994 used the IAT in the filter box.
The auto parts store should have the IAT for your truck but if they do not list it for a 1994 try one for a 1995, they are the same.
/
Moving the key on and off will not tell you much on a fuel pressure test.
With the engine not running and pin #6 grounded with the key on you should get about 45 PSI.
Idle should be from about 32-34 PSI and WOT should go to 40-42 PSI.
Your fuel pressure gauge may be off a little but with 30 PSI at idle you know you have great vacuum anyway.
All of your codes will have three numbers in them, unless you have a manual transmission.
More information on self-test go to:
Ford Fuel Injection How To Run a Self-Test
The older trucks used a screw in ACT in the intake but 1994 used the IAT in the filter box.
The auto parts store should have the IAT for your truck but if they do not list it for a 1994 try one for a 1995, they are the same.
/
Thread Starter
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The 542 code is normal if you grounded pin #6 of the EEC Self-Test connector to do a fuel system pressure check.
Moving the key on and off will not tell you much on a fuel pressure test.
With the engine not running and pin #6 grounded with the key on you should get about 45 PSI.
Idle should be from about 32-34 PSI and WOT should go to 40-42 PSI.
Your fuel pressure gauge may be off a little but with 30 PSI at idle you know you have great vacuum anyway.
All of your codes will have three numbers in them, unless you have a manual transmission.
More information on self-test go to:
Ford Fuel Injection How To Run a Self-Test
The older trucks used a screw in ACT in the intake but 1994 used the IAT in the filter box.
The auto parts store should have the IAT for your truck but if they do not list it for a 1994 try one for a 1995, they are the same.
/
Moving the key on and off will not tell you much on a fuel pressure test.
With the engine not running and pin #6 grounded with the key on you should get about 45 PSI.
Idle should be from about 32-34 PSI and WOT should go to 40-42 PSI.
Your fuel pressure gauge may be off a little but with 30 PSI at idle you know you have great vacuum anyway.
All of your codes will have three numbers in them, unless you have a manual transmission.
More information on self-test go to:
Ford Fuel Injection How To Run a Self-Test
The older trucks used a screw in ACT in the intake but 1994 used the IAT in the filter box.
The auto parts store should have the IAT for your truck but if they do not list it for a 1994 try one for a 1995, they are the same.
/
Last edited by sslick; Apr 19, 2010 at 10:18 AM. Reason: add info
Thread Starter
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Freshman User
Joined: Apr 2010
Posts: 32
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The 542 code is normal if you grounded pin #6 of the EEC Self-Test connector to do a fuel system pressure check.
Moving the key on and off will not tell you much on a fuel pressure test.
With the engine not running and pin #6 grounded with the key on you should get about 45 PSI.
Idle should be from about 32-34 PSI and WOT should go to 40-42 PSI.
Your fuel pressure gauge may be off a little but with 30 PSI at idle you know you have great vacuum anyway.
All of your codes will have three numbers in them, unless you have a manual transmission.
More information on self-test go to:
Ford Fuel Injection How To Run a Self-Test
The older trucks used a screw in ACT in the intake but 1994 used the IAT in the filter box.
The auto parts store should have the IAT for your truck but if they do not list it for a 1994 try one for a 1995, they are the same.
/
Moving the key on and off will not tell you much on a fuel pressure test.
With the engine not running and pin #6 grounded with the key on you should get about 45 PSI.
Idle should be from about 32-34 PSI and WOT should go to 40-42 PSI.
Your fuel pressure gauge may be off a little but with 30 PSI at idle you know you have great vacuum anyway.
All of your codes will have three numbers in them, unless you have a manual transmission.
More information on self-test go to:
Ford Fuel Injection How To Run a Self-Test
The older trucks used a screw in ACT in the intake but 1994 used the IAT in the filter box.
The auto parts store should have the IAT for your truck but if they do not list it for a 1994 try one for a 1995, they are the same.
/
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