misfires, rough running, cyl7 acck!

[p m]

Search DW for platinum plugs.
Swapping them out for regular, thick-electrode spark plugs would be my first step. The culprit may be different, but you may get some life out of this engine before you need to do something expensive.

Someone please explain to me why solid copper plugs would save my engine from work in the future as opposed to the platinum ones that I just installed (which were the ones in the car for the last 50k miles at least)...

Where does it say using solid copper plugs would save your engine from work in the future?
Some reading comprehension.

Now, old engines tend to foul plugs. Platinum spark plugs have tiny center electrodes that get fouled pretty quickly. Old-school ones fare slightly better - which brings me back to exactly what I said.

 

[helievacpilot]

Don't invest in the coil pack until you get those wires and plugs changed. Eliminate the easy stuff first. A cheap timing light with an induction pick-up is an easy way to check for spark in #7. You haven't said if you have swapped the leads/plugs yet to see if the mis-fire moves with them. This doesn't cost you anything.
- Bill
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[scott seidler]

Where does it say using solid copper plugs would save your engine from work in the future?
Some reading comprehension.

Now, old engines tend to foul plugs. Platinum spark plugs have tiny center electrodes that get fouled pretty quickly. Old-school ones fare slightly better - which brings me back to exactly what I said.

Now that makes more sense - thanks PM....

 

[scott seidler]

Don't invest in the coil pack until you get those wires and plugs changed. Eliminate the easy stuff first. A cheap timing light with an induction pick-up is an easy way to check for spark in #7. You haven't said if you have swapped the leads/plugs yet to see if the mis-fire moves with them. This doesn't cost you anything.
- Bill
P.S. Even if your logged out while typing, just hit submit reply, it will ask you to sign in. Sign in and it will automatically post your message.

I did swap the plugs - well technically I replaced all of them with new. I have not swapped wires yet. Today I will check for spark - and swap wires and will report back.

Thanks,
Scott

 

[scott seidler]

OK so today I finally got my new airfilter and picked up an inline spark tester to be able to check the spark in old #7.
I can definitely report there is megaspark there as the inline tester was lit up like a christmas tree. Higher revs proved even greater spark so I think the cylinder is getting spark for sure. Still no new codes at this point.
I also put in the air filter and at the same time checked all of the hoses and etc from that beyond the MAF looking for airleaks and did not find any. If need be ill check them with a propane cylinder or starting fluid since that should show if any leaks are hiding I cant see.
I also bought a new set of wires and will swap them first (warmer) chance I get as it is looking like snow at the moment and dont want to have the hood off during a snow storm.
Lastly i coated all the wires where I could reach with some silicone as a temporary stop-gap in case of arcing. There was one wire going to number 2 or 4 cylinder that showed some arcing against the valve cover so I payed particular attention to that.
Now I can still have a coil pack issue or wire that might be intermittent - Ill have to swap coil packs when I do the wires to see if then the cylinder misfire changes. Also when I get over to harbor freight Ill get a compression tester and see where the cylinders are compression wise.
So far that is where I am at.
Thanks
Scott

 

[leshassell]

see if you can spray some brake cleaner or starting fluid around the #7 fuel injector; you may be leaking air around the injector o-rings. that would cause a cylinder specific misfire but i'd also think you would be getting some lean codes as well.

 

[scott seidler]

see if you can spray some brake cleaner or starting fluid around the #7 fuel injector; you may be leaking air around the injector o-rings. that would cause a cylinder specific misfire but i'd also think you would be getting some lean codes as well.

Good idea - i can do that and will. Not sure if I can get to it over the next few days however but I will do it and let you know the outcome.
THanks
Scott

 

[scott seidler]

OK I finally got back to this D2 again as my kid had it back at school and I havent wanted to deal with it till now. Today I pulled the codes - only 1 still the cyl 7 misfire - then I replaced all the wires. Started up fine - seemed better, smoother, but still had the light come on - and it even blinked for a little bit once or twice. Its better - but still misfiring on 7. Tomorrow I am going to pick up a pressure tester and do the cylinder tests. If they test ok - Ill get a new coil pack. If Cyl 7 is low Ill try a second dose of sealant as a temporary stop-gap and read up on the head gasket change. I have no idea how hard it is to change a coil pack - napa sells them so its easy enough to get but I had a hell of a time changing the wires (thank god for my daughter and her smaller hands) I can imagine how hard it is to change the coils...........
As always - any suggestion are appreciated....
-Scott

Two other thoughts - I still have never done a top end clean with the seafoam stuff - not sure how either but wondering if that might help. The other thing is just how do i check the injectors? anyone have a link on that?
-Thanks

 

[Ed Z]

If you don't have anyway of checking the #7 injector, then you could just swap it out with one of the other injectors and see if the misfire follows... Be sure to have a complete set of replacement injector o-rings first (need 16 of em)...

 

[scott seidler]

If you don't have anyway of checking the #7 injector, then you could just swap it out with one of the other injectors and see if the misfire follows... Be sure to have a complete set of replacement injector o-rings first (need 16 of em)...

Thats a good idea and I will do that if it comes to it.
Thanks
-Scott

 

[scott seidler]

OK update!
I did a pressure test on cylinder 7 and did 5, 3 and even 8 just for comparison.
7 came up to almost 175lb. All others were around there within say 10 lbs. I also waiting 30secs or so to see if the pressure bled out - it did not.
I checked the spark plugs that were out - all had a tan color to them but #7 was a little darker than tan with a bit more black on the thread ends. The gaps were about 42-43 - so i shut them down to 40. I also switched the #7 plug with #3.
Lastly - I took out the MAF and used MAF cleaner to clean it out well. Unfortunately I snapped the plastic radiator return line in the process right on the bend! Ill have to rig up something temporarily on that to be able to test drive it...............
Ill report back in later on when I get to test drive... Though I dont think I accomplished much....
-Scott

 

[scott seidler]

Update #2!
This morning I fixed the broken radiator bleed hose with some tubing, added some water, and started her up.
Ran fine.
I drove it on backroads and the highway for about 12-15miles with no codes and no rough running or pops.
So I think the re-clean of the MAF (MUCH more thoroughly than the first time along with the contacts and etc) may have been the final answer... I doubt the plugs being at 42 instead of 40 would do it but feel free to chime in.
The only thing that gets me is why would I have a misfire on 7 with a dirty MAF. I would think if have more codes and not have one cylinder misfiring all the time.
I am taking it for a much longer run tomorrow morning and should know for sure the issue is fixed.
Ill check in after that.
-Scott

 

[scott seidler]

OK sorry for not getting back to this sooner - but things are not all well with the Disco.......
Took it for another ride that next morning - it was ok. Felt a little rough on the backroads going slow but other than that no issues. That afternoon took it for a short trip (weekend away) and at 40 miles I got stuck in traffic. Within 10 mins the light was blinking and on again. It flashed a second time while still in traffic - and then stayed lit through the rest of the trip. I pulled the code over the weekend (nice friendly parts place lent me a code reader - Thank you Beach Haven Auto Parts on LBI NJ!) and it was another P0307 cylinder 7 misfire. I recleaned the MAF, Gapped all the plugs, etc and took it home Sunday night and the truck still had issues.
Car is with my son at school for the next couple of weeks so I wont get it back until then. Ill swap to a new coil pack at that point and then see what happens.
I Havent touched the injectors cause Id have to take the intake manifold off as it appears and Im trying hard to avoid that as it looks intimidating. I did add injector cleaner.
I suppose if the coil pack doesnt work Ill try a new MAF - after that I will have to consider taking off the intake and swapping the injectors..........

Unless someone has some suggestions?

Thanks
Scott

 

[scott seidler]

Update
Today I changed the coil pack out for a new one. Took quite a bit of time and I did have to remove the plenum...............
However its done now.... Drove the car a couple of miles and it seems fine. However I have been fooled before. Ill drive it more this weekend including a 100+ mile trip home so Ill know for sure if this is the issue or not...
Thanks
Scott

 

[scott seidler]

OK - I am hoping this is the LAST update on this!
Drove the truck probably about 150 miles in total. About 100 or more on the highway.
No misfires!
Seems the coil pack was bad and it only affected ONE cylinder.
Next I need to fix the faulty brake wiring but at least the car is finally running right.
Thanks for all the help and suggestions.
-Scott