naviadvi

Hello all..I have a 98 Navigator that I had to put an insert in on the #3 plug position(blew). So I decided to change the plugs since it was due for a tune-up. When I was done and started it up, it idles fine. But when I drive, its misfiring and bucking(especially when it shifts to 3rd gear). Engine code pointed to #4 coil so I replaced it again, then #1 coil went so I bought 4 new coils for the infamous left side of the Triton. Replaced the MAF and cleaned the IAC with cleaner. Still idles fine but drives bad. Any further suggestions anyone? Btw this site is the reason I've tried all that I have so far. Thanks.

Bert

Are you still getting codes? Have you changed the fuel filter?

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Bert

naviadvi

The code is for the #4 bank. Its the same as it was because it hasnt been cleared yet. I haven't changed the fuel filter yet. It was fine before the tune-up, would the fuel filter be causing it at this point?

Bert

The filter will cause acceleration problems but not a misfire. They should be replaced periodically though. Recheck the spark plug and move the coil to another easy loaction and see if the problem follows. Also, make sure the injector wire didn't get disconnected.

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Bert

naviadvi

All injector connections are fine. Took them off one by one and while idling and the engine gets that stumble, so I think they're ok. That is the 2nd coil that I've replaced on that cylinder and the same symptoms remain. Highly doubtful that I would get 2 brand new coils that are bad. Even when in park and I raise the idle, I can feel the misfire. But when I get off the pedal it's fine.

Bert

Did you swap coils with another cylinder?

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Bert

naviadvi

No I haven't swapped coil packs yet. I believe the coil I took off the #4 cylinder is still good being that I"m having the same symptoms. I'll use it to swap coils. Let you know in a few.

naviadvi

Ok I swapped around coils to rule out that problem. Coils are fine and I'm still misfiring. Put on a new fuel filter too. I went thru the injectors one by one and the engine stumbles when I pull the harness off so I believe they're fine. Also put on a new fuel pressure regulator. If anyone has another suggestion I'm all ears because I don't know where else to go. I do not want to give Ford $100 for a diagnostic.

naviadvi

I've tried everything i can think of to solve this shudder that the truck is doing. After research i came across a posting that talks about the pcv elbow behind the intake on the firewall that gets worn and breaks which causes a vaccum and creates symptoms that my truck is having. Its supposed to be hard to get to already but mine seems to have a different design from what i've seen in photos. One of my hoses coming from the pcv valve goes behind the intake and disappears into the firewall.I was also asked if mine was heated or not and maybe thats why I cant find it. I can hear what I believe is a vacuum but cannot find the source of it. Any help is greatly appreciated. Btw it is a 98 Navi 5.4L FightinTriton. Fighting me that is .

naviadvi

I've tried everything i can think of to solve this shudder that the truck is doing. After research i came across a posting that talks about the pcv elbow behind the intake on the firewall that gets worn and breaks which causes a vaccum and creates symptoms that my truck is having. Its supposed to be hard to get to already but mine seems to have a different design from what i've seen in photos. One of my hoses coming from the pcv valve goes behind the intake and disappears into the firewall.I was also asked if mine was heated or not and maybe thats why I cant find it. I can hear what I believe is a vacuum but cannot find the source of it. Any help is greatly appreciated. Btw it is a 98 Navi 5.4L FightinTriton. Fighting me that is .