bad fuel injector after fuel filter change

Drcoffee

Senior Member
Maybe its a coincidence but I changed out the original fuel filter with a new OEM fuel filter on Saturday and on sunday while test driving it after changing the steering rack guide the truck started running rough. When I got back home and popped the hood, sure enough the engine was shaking. I goosed the throttle a couple of times and then WOT a couple of times and it smoothed out again. I pulled the codes and nothing recorded. This morning I started it up and now I have a check engine light on. It still runs smooth so I checked the codes and now I get a P0302 #2 cylinder misfire. I cleared the codes and my daughter drove to school (15 minutes) and the check engine light stayed off. I'll keep an eye on it but I have to assume that something lodged in the #2 injector from the new filter. When I replaced the filter, the gas flowed back out of both lines when the old filter was removed flushing out any local crud. So that leads me to think something was in the new filter.

Anyway, does a bad injector work intermittantly or do you think whatever it was has cleared the injector?

Has anyone heard of this before?

I did a search but nothing came up linkng a new filter with a misfire.
 
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Sounds like something got lodged in the injector like you think. I've never heard of it happening but I think its not coincidence that it happened the day after you replaced the filter. Something was knocked loose either by the new or old one. Hope it passed through the injector, and wont have any problems.
 
So I really need help now. The check engine began flashing and the engine started shaking again. I limped it home for a looksee. I pulled the #2 plug wire while it ws running and it had no affect on the idle, still rough. I could hear the spark jumping in the tube so I know its getting spark. It has to be the injector. What I don't understand is why when I check the codes, nothing is recorded and the check engine light is off. Yet it still isn't running smooth.

Is there anyway to get it working without replacing it? If not, do I need to replace all or just the bad one? Who makes a good remanufactured injector?
 
Personally, Id buy the strongest injector cleaner you can find. Obviously you've narrowed it down to #2 injector. If that doesn't work, Id replace the injector with an OEM.
 
Never heard of that happening before but it certainly is an odd coincidence at best. However, if what you guys are saying happened, happened, pull the fuel rail first. I would think there is at least a chance something is stuck in the rail at the injector. Probably a lot easier and cheaper to clean the fuel rail than to replace the injector.
 
Its still bugs me how this happened. I primed the fuel rail4 times, key on and off to presurize the fuel rails. If it was starved for gas, even for a moment, would that cause an old injector to fail?

If I have to remove the intake, I might as well replace the valve cover gaskets (leaking badly) and replace all 3 injectors. How long of a job is that to DIY it? Is it as tough as it looks?

I keep thinking back to removing the fuel filter. When I dumped out the gas from the filter, the gas coming out of the outlet side(engine side) wasn't clean like you would think but dirty, muddy colored. The only other thing I had done differently was filling up at the local Sam's Club gas station last week. I guess I could have gotten bad gas, maybe water in it.?

Update: This morning I started the truck to move it into the garage and it runs smooth but the P0302 code came up again. Can an injector work when cold but fail when hot? Is this a common symptom?
 
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If it was the original filter, the gas will look awful. Mine was no better, it looked like three day old Folgers in the pot.

Instead of replacing three, I'd send the working five to witchhunter.com and get them cleaned and bench tested. My friend used them to clean his injectors in his Mustang back in 08 and had no problems with them since.

Injectors can go bad for a myriad of reasons. It may have been on its last leg before the filter change.
 
If it was the original filter, the gas will look awful. Mine was no better, it looked like three day old Folgers in the pot.

Instead of replacing three, I'd send the working five to witchhunter.com and get them cleaned and bench tested. My friend used them to clean his injectors in his Mustang back in 08 and had no problems with them since.

Injectors can go bad for a myriad of reasons. It may have been on its last leg before the filter change.

The core fee is only $10 so I'm going to keep the old ones and send them to Witchhunter for a rebuild and then replace 1,3 & 5 when I get ambitious. I just want this thing back on the road already.
What happens if its just broken/DOA? Does witchhunter rebuild it or notify you its dead? I guess I'm concerned I'll send them out to find out they aren't rebuildable and need new injectors anyway. Also, if they clean them for $30 what's to say they won't fail in a month? They are 12 years old, right.
 
Drop WH an email and see what they say.

Who is to say they won't fail in a week, month, semi year? Only with new ones do you take that risk out of the equation.

I have seen 20 year old Motorcraft injectors rebuilt and work just fine.

Knock on wood, with twenty years of driving under my belt, I never have had an injector go south on me.
 
I'm certainly not an expert on the subject but given the fact the injector is really an electrical component, it's not out of the question that they would work when cold but not when they get hot. Probably worth a call to Witch Hunter anyway to look into it.
 
I called WH and had a good conversation with them. What I did was order 3 GB Reman injectors from rockauto and when I get these installed, I will send the old ones to WH to clean and test. That way I can switch the pasenger side out later and have all 6 running like new. Then either sell the old working injectors or keep them as spares but I doubt I will ever need them. Another Saturday working on this truck. It might be ambitious but I want to get the new injectors in, new valve cover gasket in and the Tundra brake swap. The brakes should be a 1/2 job. The strategy will be install the injectors and pressurize them to check for leaks. Once that's done, then clean the valve covers and paint them blue and while they dry, do the brakes. The paint is duplicolor brake caliper paint which is fast drying.
 
You're having the same issues I had, and it was a bad injector. I did a lot of useless work to finally get mine running. In the end, I left 5 old injectors in there, and simply replaced the bad one with a remanufactured unit.

For what it's worth... buy them locally! At least you have a face to put with any issues you may have. (my 2 cents)

Good luck with the repair.... BTW, it's not that hard of a job, just make sure you keep all your nuts and bolts in order. I separated everything in containers.

Top plenum hardware....

bottom plenum hardware....

Fuel system hardware.....


The vacuum lines, throttle, transmission, cruise control cables and electrical connectors are all pretty easy....... :)
 
Is the CELL still flashing or did it go back to solid?

The CEL had come on flashing, then went solid. Then it turned off completely but still ran very rough. I couldn't pull a code until the next morning with the CEL off is when I pulled the P0302.
 
You're having the same issues I had, and it was a bad injector. I did a lot of useless work to finally get mine running. In the end, I left 5 old injectors in there, and simply replaced the bad one with a remanufactured unit.

Fightman80, Was there a special way you had to lift the fuel rail off the injectors. I see there is a hard line connecting the left and right rail in the front. Do I need to remove the banjo bolts or anything else other than the 3 hold down bolts? I'm a little concerned I will cause the other side to start leaking. How did you do yours?

Thanks
 
If you only plan on lifting 1 side, you have to disconnect the two, by taking out the end bolt on one side. The hard line runs from one side to the other, and can be detached by unbolting the end of the fuel rail. Be sure not to lose the little copper washer that is in that location, as it acts like a seal.

Aside from that, when lifting the rail off, do one injector at a time, and twist the injector while doing so. You should replace all of the O-rings on the one side, to avoid leaks, and should buy enough for both sides (just in case). You can return the one's you don't use after the job is done.

If you have any other questions, send me a PM, and I'll do my best to answer accordingly. :)

Good luck man!
 
hey DR coffee, i also just finished dealing with an injector problem, its not to hard to tackle, but dont buy ****ty ebay injectors like i did lol. anyways itd be good to replace your gaskets while your in there. Im not sure if the code told you what cylinder was misfiring, but mine was number 4. anywho theres only a few tricky bolts and isnt that tough, if you have some mechanical knowledge it shouldnt be a problem ( i wasnt that confident with the injector change at first, but my dad showed me how to do it, I had to replace the injectors a couple of times lol)

good luck let us know how its going

ps i am also a coffee dr! Im a supervisor at starbucks lol
 
if you have some mechanical knowledge it shouldnt be a problem ( i wasnt that confident with the injector change at first, but my dad showed me how to do it, I had to replace the injectors a couple of times lol)

I changed out the injectors on my 99 corvette once or twice so I'm okay with that part of the job. Its just getting down to them I'm not looking forward to. Back then I forgot to buy vaseline to do the install, so I had to go to my neighbor and ask for some vaseline. LOL In hindsight I should have waited for my wife to come home so I could drive to the store.

I can just imagine what they said when the door closed. "Oh sure you need it for the car." wink wink.
 
Update:

The install went okay. #3's plastic base broke when the rail lifted and #5's bottom o-ring was missing. The new injectors went in #2,4,6 and the now working old ones went into #1,3,5. She fired up and purred like at kitten. After 100 miles, no problems and no codes.

I sent the 3 old injectors to Witchhunter for repair. I found out last night that #2 had an intermittent coil and was DOA. So it wasn't the Sam's gas or fuel filter that caused the P0302 code. Just coincidence and bad luck.

On the good side, I replaced the leaking valve cover gaskets so that's one job I can remove from the long list of maitenance items.

Thanks for eveyones input.
 
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