99 Explorer firing issues, I think

[M1299M]

Here is the down low on my issue:
I have a 99 Explorer XLT AWD, 142,000 with a 5.0L 302, awesome PONIES!!!! A week ago on my way to work my check engine light starting blinking but not staying on. I researched online and everything pointed to bad plugs and misfire. So knowing plugs haven't been changed since I have owned it I started there. Now my idiot light was blinking on and off more frequent. I stopped at the auto parts store and they plug in the OBD II and it said misfire #1 or O2 sensor upper bank. Now the guy asked me about using Seafoam, never have until that day. Ran it through it puttered a little for a few days and then quit, but then the idiot light came on and stayed on. A buddy at work brought his code reader and it said misfire. He said bad coil or wires. He suggested that I switch #3 and #1 wires around to see if the misfire follows to rule out the wires. Ran fine for 4 days and then started acting up. So I thought plugs were dirty from the treatment, cleaned plugs and switched wires back on Monday. Yesterday going to work, when pushing gas to go up a hill it felt like it was not getting enough spark and was struggling for power. So today I switched the wires again to see if that is the issue. It helped a little but still struggles. I am trying to figure out if this is a problem with the plugs, wires, coils, or something that I haven't looked at or thought of yet.
Any thoughts would be very helpful before I spend money I don't have on parts that I don't need!!!
Thanks all in advance!!!!

 

[koda2000]

you should have changed the plug wires when you changed the plugs and you should have done both at around 90k. what brand a type of plugs did you put in?

 

[M1299M]

I know the wires need replaced, but on limited funds I have to start where I can. Could the wires be the problem and not the coil? Electrical issues are not cheap but I am trying to be thrifty on this one! Thanks koda2000

 

[koda2000]

I know the wires need replaced, but on limited funds I have to start where I can. Could the wires be the problem and not the coil? Electrical issues are not cheap but I am trying to be thrifty on this one! Thanks koda2000

i would start with the plug wires. they're not designed to last 150k. again, what brand/type of plugs did you install? if you put in anything less than a Motorcraft or Autolite double platinum you can have problems and/or short plug life. Bosch plugs are terrible in these engines.

 

[M1299M]

New plugs, wires, and driver side coil. Still acting up, should I go for the o2 sensor now?

 

[koda2000]

New plugs, wires, and driver side coil. Still acting up, should I go for the o2 sensor now?

for the third time, what brand and type of plugs did you install?

 

[pbnj22]

New plugs, wires, and driver side coil. Still acting up, should I go for the o2 sensor now?

Yeah what koda said.. What brand? I replaced plugs and wires with a brand new Bosch set and still had your symptoms and had to redo everything with motor craft parts to get it go away.. You could have switched wires around then cleared the codes and rechecked which specific cylinder was misfiring and if the misfire followed the cylinder that had the wire switched out then you can tell if it was the wire or something else.. I believe you can do the same with the coil as well but my bet is you just need to buy the correct plugs and plug wires then reset the computer and you'll be good to go.. These engines are finicky about their plugs and wires !!

 

[drdoom]

If you are on limited funds you can test those components before replacing them. You can test the oxygen sensor too. A manual would help you should get or borrow one.

 

[Bandit Customs]

Can you give us the exact codes the pcm had stored? i too am curious about what exactly "02 sensor" code you got - there are several.. Depending on how long the engine was ran with misfires and what codes you are getting, the misfires could have fried the cat convertor. Please tell us the codes you have recorded since this has happened. Also, i agree with the motorcraft suggestion - these engines are picky about plugs/wires - motor craft in this instance is the way to go. That's what parts we install on all of our customer vehicles

 

[M1299M]

Napa wires
Bdm ignition coil
Auto lite platinum spark plugs

I will post the codes tomorrow evening as I forgot to write them down. Someone mentioned to me that it could be the crank position sensor going bad since it keeps throwing the #1 misfire. Sorry for the delay in response guys, working everyday!

 

[Turdle]

ok, for the most frugal type of troubleshooting on a #1 misfire (p0301 code) when the spark plug wire is suspect, swap the #1 and #2 spark plug wires around, you should now get a p0302 code if the wire is bad.

If the code p0301 persists, the new spark plug could be bad, or, the #1 fuel injector could be faulty.

 

[M1299M]

Turdle, it is the p0301 trouble code. I swapped the wires and still same things. So thinking the plug could be bad I put the wires back to original positions, and swapped two plugs. Still the same code. Would this be the fuel injector for #1 cylinder now? Also, should I be worried about a burnt cat? This issue has been up and down for about two weeks and I am expecting the worse on the cat issue and hope I am wrong!!!!

Thank you!!

 

[Turdle]

Yes. You have done a pretty good job of narrowing it down. I would bet the problem is a faulty fuel injector.

 

[biff9703]

M1299M, I just took the 5.0 out of my ex and put a 347 in. I have a set of good used injectors. You can have one of them if you want it. Send me a pm with your address, and I will send it your way.

 

[Turdle]

M1299M, I just took the 5.0 out of my ex and put a 347 in. I have a set of good used injectors. You can have one of them if you want it. Send me a pm with your address, and I will send it your way.

I am impressed by your offer! That is what we are all about here

The 97 injector may not work for him though. I assume his truck has a returnless type fuel system which uses different injectors.

I am pretty sure he needs a light gray (white) one, 98 and down are orange. The electrical connection looks very similar, but they will not connect properly. It is possible he has a late 98 build (early 99) which may have orange injectors.

 

[biff9703]

You're right, mine are orange. Just trying to help out if I can. I don't have much else left except the long block. I used all my external stuff on the 347, so the pickings are pretty slim! If anyone else needs orange injectors, I would rather they went to good use instead of taking up room in my toolbox!

 

[M1299M]

Biff9703,
Thank you for the offer, but turdle is correct I have the light grey whitish injectors. I am going to have to try the used parts store junk yard tomorrow to see if they have any. I hope that fixes my issue I'm tired of the loud like I have a constant card in my bicycle noise when I drive!!!

 

[Turdle]

This very same issue is happening with my truck,however it is worse. I suggest you check the compression on cylinder 1 before anything else.

 

[M1299M]

Blown head!!!!
Everyone I appreciate you assistance in troubleshooting my issue. I went to the garage after work today and some poor performance of my truck, 70 at the bottom of the hill and topping it at just over 45 is not good with 8 cylinders.
After the diagnostic test the following codes were revealed:
Misfires on 1-3-4
P1131 (O2 sensor bank 1 sensor 1)
PO 301B |
PO 303 |= All three mean plugs and wires
PO 304B |
PO 136 (O2 sensor bank 1 sensor 2)

After listening to when started he instantly heard the valves knocking and said the passenger side head is shot!!!

Great more money that I don't have to spend. Anyone have a good used cheap motor close to PA or know where I can get a head assembly at a good price???

 

[field]

Turdle's advice is good.

ok, for the most frugal type of troubleshooting on a #1 misfire (p0301 code) when the spark plug wire is suspect, swap the #1 and #2 spark plug wires around, you should now get a p0302 code if the wire is bad.

If the code p0301 persists, the new spark plug could be bad, or, the #1 fuel injector could be faulty.