My never ending problem

[kkushner4474]

Check engine light
Codes read misfire in cylinders 3 and 4

if this is in the wrong area please let me know.

First got the codes with original spark plugs so I changed them and cleared the codes and received the same codes again so I got new wires and again the codes are back so i cleared the codes again and again they came back

Every time it happend is when I am in 5th gear 70 mphs and about 3000 rpms


I have spark plugs that are about 1 month old, spark plug wires that are 2 weeks old

I have tested my coil pack jsut as it were to be serviced and everything checks out

i was thinking faulty fuel injector

So what’s wrong???

Any way to test a fuel injector or any other tests i could do to figure
ths out???

Thank you
Kyle

http://legacygt.com/forums/older-legacy ... -help.html (http://legacygt.com/forums/older-legacy-performance/37352-help.html)

[sheepdog]

You could check the voltage for each injector, that will tell you whether they are getting a signal or not. Then you kinda have to replace the injectors, and if the problem goes away, that was the cause. Persnoally I don't hink that would be it if both 3 and 4 are misfiring, it sounds like some kind of electrical problem somwehwere along the line......

[AussieDan]

I am/was having a similar problem.

I have a set of iridium plugs with ~1500 miles on them, and was running 8.5mm wires with the stock (118k) coil.

When cruising in 5th around 75-80 after about 20 minutes it would start throwing misfire cyl 1 and 2 cels.

I changed the coil yesterday and haven't had another cel so far (driven about 60 miles), going to give it a more thorough shakedown on the highway this weekend and see if it comes back.

My FSM also seems to indicate that this can be caused by a clogged fuel filter (mine is new) or a failing fuel pump causing low fuel pressure and resulting in a lean condition.

[kkushner4474]

I drove my car down to the shore

I held the speedometer at 60, 63, 65, 67, 70, 73, 75, 77, 80 and took it up to 90 for a bit
NO Check engine light and it passed that special number of 70 mph and 3000 rpms in 5th

After about hour and a half of driving at various speeds from 60 to 85 the check engine light comes on at 70mphs 3000 rpms 5th gear and flashes for 10 secs then goes solid

then on the way home from the shore its solid the whole way till about an hour in the light flashes fro another 10 secs and goes back to solid driving in a range of 60 to 70 mphs

[ivwarrior]

Out of curiosity, what brand of plugs and wires are you using?

A flashing check engine light isn't good. It means something's going on (generally bad misfire) that has potential to cause worse problems.

[kkushner4474]

bosh wires and spark plugs im not sure about

[strat81]

when you get the code, does the car start running like it's on 2-3 cylinders instead of all 4?

i've been having a similar problem with my car (although i haven't found it's at a specific speed or rpm)

changed: plugs, wires, coil pack, fuel filter... next up for me is cleaning the maf... after that probably injector replacement...

[kkushner4474]

After the codes show up the car still feels like it is running on all 4 cylinders

Every once in a while I will feel a lag but it will pick back up soon after

[kkushner4474]

ran codes today at autozone before trying anything else and now im down to just cylinder 3 misfireing

so i have another bottle of fuel injector cleaner and going to see how that works out

leaning towards a faulty fuel injector

[strat81]

if it feels like it's running on all 4 cylinders though when it's throwing the codes, it sounds more like a faulty code than anything.

mine is noticeably different. if you drop a fuel injector, you SHOULD be able to feel a difference...

[kkushner4474]

So I cleared my codes after putting in a new fuel filter and drive my car about 2 miles and got a new code

Drove up to AutoZone today and have p0507 and p0303

Idle higher than normal and misfire in cylinder 3

[white96gt]

injector sticking open? (higher idle due to more fuel... misfire due to too much fuel)
just an idea... maybe swap injectors to other side, see if the code changes?
Don

[AJM]

Idle higher than normal and misfire in cylinder 3

Wow, that is exactly what is wrong with my car currently. I have to get this fixed before I sell it...grr...