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P0300, PO303, MAF sensor

Daisywheels

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Hi, I've been posting questions regarding the same problem, and I'm not sure if I should start a new thread each time or not? Can someone please advise?

The definite common denominator for my problem from all you guys is a vacuum leak. Obviously I have been unable to find it!

I had P0300, and P030X codes, so far I replaced plugs, wires, and coil pack. I had already replaced the MAF sensor back in August. Now my codes are P0300 and P0303

I tried to test the cylinders by removing one of the wires from the coil pack back in the Summer while running. Not a good idea - ZAP. So I finally decided to pull the plug wires from the plugs themselves yesterday. Good news is I did not get zapped, but there was no change in idle while pulling wires on the ENTIRE BANK 1. There WAS spark getting to the wires as it bounced off the heads with wires in hand. Bank 2 wires pulled did what they were supposed to do - lowered idle noticeably.

I'm still at a total loss as to why this truck won't cooperate. One last piece of information is on my OLD MAF sensor, I was getting P0174 (lean code), and with the new MAF sensor, the scanner was reporting P0102 Mass or Volume Air Flow Circuit Low Input. Basically the PO174 went away and was replaced with P0102 with the new MAF sensor.

BOTH banks LTFTs read 25, which just tells me the computer can't calculate it properly due to the motor not running properly.

ANY help would be greatly appreciated, and if I left anything out please ask!

[EDIT] Yes, I do have a flashing CEL.

Thanks - DW
 


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morbid81

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the intake gaskets upper and lower can cause this issue as well. also a bad injector. these are notorious on the SOHC v6.
 




boominXplorer

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What spark plugs are you using?
 




Daisywheels

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the intake gaskets upper and lower can cause this issue as well. also a bad injector. these are notorious on the SOHC v6.

Yeah, forgot to mention both the upper and lower gaskets were replaced also - after the problem first began. My mechanic did it, so I don't know if he knocked an injector loose or what. I'd have to take at least the upper intake manifold off to get to the injectors right?

Thanks for your help! - DW
 




Daisywheels

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What spark plugs are you using?

I'm using the same brand/type that I pulled out - Motorcraft AGSF 22FM single platinum gapped to .054. The plugs that came out didn't look that bad. Even the wires looked fairly new. -DW
 




boominXplorer

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Can you confirm the spark plug wires are ran to the correct cylinders? The coil pack is numbered on the white area on the top of it and passenger front cylinder is #1
 




Daisywheels

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Can you confirm the spark plug wires are ran to the correct cylinders? The coil pack is numbered on the white area on the top of it and passenger front cylinder is #1

Yes, I double/triple checked that. I numbered the new wires for each cylinder number, then put them on the new coil pack (no numbers on new coil pack). Coil pack wired from front to back:

5-6-4
1-2-3

Would anyone recommend removing the wires from the coil pack one at a time while the engine is running? I got zapped pretty good the first time I tried it, so that's why I went to the actual plug area. But some are so freaking hard to get to. Thanks! -DW
 




Daisywheels

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Coil pack resistance

I also tested the resistance of my old coil pack towers, and compared them to the new coil pack. This was off the truck.

Old coil pack "towers:"

3-4 = 12.70
2-6 = 12.85
1-5 = 12.62

I saw somewhere that these are a little high from the normal range, but I wasn't sure if the test was supposed to be with the coil pack on the truck.

The new coil pack numbers were all a bit higher, all hovering a bit above 13.00. I found that disconcerting. Should I?

Thanks again! -DW
 




boominXplorer

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Yes, I double/triple checked that. I numbered the new wires for each cylinder number, then put them on the new coil pack (no numbers on new coil pack). Coil pack wired from front to back:

5-6-4
1-2-3

Would anyone recommend removing the wires from the coil pack one at a time while the engine is running? I got zapped pretty good the first time I tried it, so that's why I went to the actual plug area. But some are so freaking hard to get to. Thanks! -DW

Its not the best idea to pull them off the coil pack, that spark will want to jump anywhere and you will get zapped. You can do it but its a last resort idea and MIGHT damage the coil pack.

I have also personally installed a set of ford spark plugs in an explorer directly from the dealer and immediately it had multiple misfires. They were the exact ones it called for and I triple checked it. I swapped in some autolite double platinums I had laying around and it purred like a kitten. Here's a diagram again for a 4th check if your interested.

attachment.php
 








Daisywheels

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Idle problems

Another tidbit I may not have mentioned is that the truck idles high 1,800-2,000 RPMs) - even at normal operating temp, but put it in any gear, the motor will really sputter and run at about 500 RPMs. This is just about a lost cause.
 




Daisywheels

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More symptoms I should add:

Upon startup, there is a sputtering sound coming from the back side of the engine. This goes away after just a few minutes. However, when putting it in gear, and driving it, this sound returns. It's even much more pronounced and rapid under load (accelerating). I'm wondering what could be back there that the noise is coming from? I'm not giving up! -DW
 




Daisywheels

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Long term fuel trims

One last note - checked my LTFTs at idle and both banks were running about 19+. I increased RPMs to 3,000 and watched both my LTFTs go to 0. That's a good thing right? Absent the high readings at idle. Thanks! -DW
 




morbid81

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sputtering under load sounds like a exhaust leak to me. Does it resemble a Valve tick? Yes to your earlier response you have to take the manifold off to get at the injectors. Have you tried cleaning the IAC to resolve your high idle issue? Possible it could be bad as well.
 




Daisywheels

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Exhaust leak

sputtering under load sounds like a exhaust leak to me. Does it resemble a Valve tick? Yes to your earlier response you have to take the manifold off to get at the injectors. Have you tried cleaning the IAC to resolve your high idle issue? Possible it could be bad as well.

Sorry Morbid, I did not receive a notification of your post. YES, I do have an exhaust leak. I always had it even when it ran fine. However, I would not think that would cause the entire bank 1 not to fire, or would it? The exhaust leak is also on bank 1.

IAC valve was cleaned and appears to be working properly. I unplugged it, idle dropped, and even got a DTC, but that DTC related code went away upon plugging the IAC back in. I am going to get a noid light to see if the injectors are getting current and pulse. I tested the resistance of the 3 injectors on bank one, and all were spot on at 16.0 exactly. I'm aware that doesn't mean the injectors are spraying fuel.

Right now, the upper plenum is off, andI was wondering if I could releive the fuel pressure, unplug the coil pack, and turn the motor over for the noid light test without the upper plenum attached? Those injectors are a bitch to get to. Thanks for replying! - DW
 




morbid81

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Bank 1 is the passenger side and the manifolds are known for cracking causing the leak and a check engine light, vac leaks can also cause a misfire along with injectors, does the ticking noise go away after the engine warms up? i have the same leak and ticking noise because of it, gasket is barely left over, and im sure manifold is cracked.
 




Daisywheels

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ticking noise

Bank 1 is the passenger side and the manifolds are known for cracking causing the leak and a check engine light, vac leaks can also cause a misfire along with injectors, does the ticking noise go away after the engine warms up? i have the same leak and ticking noise because of it, gasket is barely left over, and im sure manifold is cracked.

I've developed a ticking noise INSIDE the motor that does not go away. The sputtering sound is different and will always be there under load. I will hear it for the first 60 seconds or so, but won't hear it again until I drive it. I think I know where you are going - that heat expands the gaskets and manifold, but I'm not sure that is the reason my entire bank 1 won't fire. My mechanic thinks the exhaust leak is downstream of the manifold - loose bolts somewhere on the cat back. Mechanic has been sick for months now, so I am on my own.

So can I turn the motor over without the upper manifold attached, or bad idea? I may as well check fuel pressure before I relieve it. Thanks! DW
 




morbid81

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This ticking noise is it on cold start? or does it sound more like a rattle?
 






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morbid81

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Im still leaning toward exhaust leak, you probably got a hole somewhere and your hearing the exhaust escaping through it, this is what is probably setting off the lean code because it can calculate the air fuel mixture properly. High idle I couldn't tell ya on that. when you changed the plugs you didn't drop any into the wells did you? if you did you could have bent the electrode that will cause a misfire. that is probably the ticking noise your hearing as well is the exhaust leak. i would test your injectors and keep searching for a vacuum leak for the mis fire code. are you wires fully seated on the plugs and distributor? you can try a compression test as well i hear this will set a mis fire code. check the injectors on the affected cylinders as well.
 




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