2001 Screw running BAD
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New User
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From: Northern California
2001 Screw running BAD
Hello All, First post here. Been reading through this forum all week and trying what I've learned here but now its getting expensive. 2001 F150 Screw 5.4 w/150k (well maintained). Started suddenly missing at idle last weekend. Code P0301, so I changed Autolite Double Platinum plugs. Still P0301, changed COP. Code P0300, P0301, P0307, Cleared codes, cleaned MAF,swapped coils on Cyls. 1&2. Code P0301, new injector Cyl. 1. The reason for changing this injector was -no change in running condition when wiring disconnected. Now Code P0300, P0301, P0306 and barely made it home. It's worse now! Checked all over to see if I knocked something loose but couldn't find anything Today I'm cleaning throttle body & EGR. Sorry about the long post but it's been a long week. What do you guys think? Why is it always Cyl.1. Plugs I removed were not too bad. Thanks for reading.
Lead Driver
Joined: Sep 2006
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IMO, your tip off is the code 300 a random missfire code.
This tells me it's something else involved with all cylinders.
Suspect the crank position sensor, the cam position sensor, fuse seating in the distribtion panels, PCM relay or wire ground out in the harness.
This tells me it's something else involved with all cylinders.
Suspect the crank position sensor, the cam position sensor, fuse seating in the distribtion panels, PCM relay or wire ground out in the harness.
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From: Northern California
Thanks Bluegrass 7, I'm out front now working on it. This is my first issue with this truck, so I don't have a manual yet. Can you direct me to to crank sensor? I found and cleaned the cam sensor. Would these sensor throw a specific code?
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Okay, heres where I'm at. Changed fuel filter & crank sensor, cleaned throttle body and MAF, checked and cleaned all sensor connections, checked for vacuum leaks, reset computer, ran it - still missing, but not nearly as bad as previously. When I changed the filter I tried to pump some gas in a bottle with the key on -no flow at all. It would only pump when cranking. Is this correct ? Seems it should pump with just key on.
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From: Northern California
Test driving, the miss is still there. Engine vacuum is 15 lbs steady. While idling, disconnected and reconnected cam sensor, IAC connector, fuel regulator vacuum line, no change in running condition as I disconnected each. They all returned codes (P0113, P0340, P0172). I think this tells me they are working. I'm ready to change 02 sensors if you guys think I should, but so far everything else I've replaced has had no improvement. Please see my post above about the fuel pump.
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Lead Driver
Joined: Sep 2006
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The fuel pump does not contiiniously run with just the key on. Only a second or two.
When cranking, the crank and cam position sensors are the reference for the ignition timing, injector operation and trigger the fuel pump to run only as long as the engine is running.
Intake vacuum should be at least 18 inches on a gauge. 15 is not normal.
When cranking, the crank and cam position sensors are the reference for the ignition timing, injector operation and trigger the fuel pump to run only as long as the engine is running.
Intake vacuum should be at least 18 inches on a gauge. 15 is not normal.
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New User
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From: Northern California
Thanks Bluegrass, Measured vacuum at the port located on the firewall near the battery and solenoid. Sprayed WD40 around the motor to locate any vacuum leak and found nothing. Went to Autozone to buy 02 sensors and they talked me out of it. Said I should have gotten a code pointing to the 02 sensors. I can't figure this out. Everytime I start this motor it seems to run a little bit different (better or worse). 02 sensors? MAF sensor ? Bad gas ? Please help as I haven't found a suitable manual yet.
Lead Driver
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The only thing now is to look cloesly at all the harness for the injectors and coils etc for a rub thru even out of normal sight.
You did a lot of things and may have introduced a second problem along with the original.
Good luck.
You did a lot of things and may have introduced a second problem along with the original.
Good luck.
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Back to the top- still need help! Per Bluegrass 7 recommendations I visually checked the harness for shorts. Re-checked all I've done sofar. Re-measured vacuum at brake booster port -19 lbs steady. 15 lbs stated in previous post was incorrect. Fuel pressure is steady 30 lbs at all speeds, 40 lbs with disconnected regulator. I'm thinking next step is upstream 02 sensors. Is this sensible? 150k on current sensors. Please help, tools and parts are at $450 and my wife is giving me that look.
Cargo Master
Joined: Dec 2006
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From: Central NY
Originally Posted by baddaddy
Back to the top- still need help! Per Bluegrass 7 recommendations I visually checked the harness for shorts. Re-checked all I've done sofar. Re-measured vacuum at brake booster port -19 lbs steady. 15 lbs stated in previous post was incorrect. Fuel pressure is steady 30 lbs at all speeds, 40 lbs with disconnected regulator. I'm thinking next step is upstream 02 sensors. Is this sensible? 150k on current sensors. Please help, tools and parts are at $450 and my wife is giving me that look.
Lead Driver
Joined: Sep 2006
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I have consulted my Ford disc info for the code 300.
It says the following to check out.
Cam position sensor, low fuel, stuck open EGR, blocked Egr passages, Fuel injectors, EVAP Can purge valve, base engine faults or anything related to each of these areas.
The fault seems to be sleightly changing because the code 300 can't id a peticular cylinder, then you get codes for individual cylinders. This is the part that is changing on you.
What is your current state?
Best I can do from a distance and my poor cheap crystall ball.
Over the years I have often had to begin again at the beginning and look/check more, then usually find the problems.
Always clear codes after dong work so you see the latest code history. This keeps confusion to a min and makes it poosible to see progress or the inadvertant introduction of another fault along with the original.
It says the following to check out.
Cam position sensor, low fuel, stuck open EGR, blocked Egr passages, Fuel injectors, EVAP Can purge valve, base engine faults or anything related to each of these areas.
The fault seems to be sleightly changing because the code 300 can't id a peticular cylinder, then you get codes for individual cylinders. This is the part that is changing on you.
What is your current state?
Best I can do from a distance and my poor cheap crystall ball.
Over the years I have often had to begin again at the beginning and look/check more, then usually find the problems.
Always clear codes after dong work so you see the latest code history. This keeps confusion to a min and makes it poosible to see progress or the inadvertant introduction of another fault along with the original.
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How about the power valve? Something I was told that I had wrong with mine the last trip into the dealer.. I have a 98 w/5.4 and 120000 on it and it was idling rough to where you had to power block it to keep it running... thats what they told me the changed. Hope that helps.
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From: Northern California
Sorry about the delayed response guys. Since my last post I replaced the upstream 02 sensors - no change. Now I'm getting consistent P0301 & P0306 codes. Bluegrass, Thanks for looking that up. It appears I've addressed all those possibilities except the EVAP valve and base engine faults. I'm starting to think maybe something internal broke but I always thought that would show on the vacuum gauge. I'm stumped but not giving up yet. NavyFlyer, I can't find any reference to a power valve in my Chilton book. This thing never stalls, it just won't run like it used to. Thanks to all for the help,
and I'm still open for suggestions. PCM? DPFE? MAF? SOL?
and I'm still open for suggestions. PCM? DPFE? MAF? SOL?