VERY Hard Misfire! Cant Find The Problem..

[BoostFiend510]

Hi forum im new here and i have a problem i cant find anywhere on here... So i just bought a 240sx with sr20det redtop. Everything was fine untill i had a turbo sputter and ended up changing the spark plugs ( which all but 1 were FRIED ) which cleared thing up and was running like a beast.. Then after a ride i came back and was parked and i was hearing a bad backfire so i waited a minute and turned it off. Checked the spark plugs which were BRAND NEW, and one was FRIED again! i changed it out and now its just misfiring very bad and running very rough and also dumping gas running rich ... We checked the coil packs and it seems cyl. #1 isnt working but still has spark? when the car is running and you take off the coil plug on cyl #1 nothing happens, but all others will change the idle. Im very confused and needs some help. Anyone have some advise????

P.S I will also post some pics and some videos if i can get some help here.. Thanks guys

[mytagsucks]

Does it sound fine at idle for a little then start misfiring and bogging down?
I've pretty much had the same problem with mine. You need to doublecheck your coils first. Then I'd start looking at sensors.
I have a hunch it could be your coolant temp sensor because suprisingly this can cause your sr to run like complete crap. Check your MAF, CAS, IAVC, and for any vaccum leaks too.

[BoostFiend510]

Heres a video of the start up... I'm going to check all that and get back to you and see give an update on how its going... If anyone else has some suggestions please let me know! Thanks

-------> YouTube - Sr20det (http://www.youtube.com/watch?v=LVguq5j5S4M) <------------

[Okinawandrifter87]

Have you checked your O2 sensor? jw

[DailyDrivenS14]

thats a hard miss on one cylinder lol, Check compression on the one that doesnt respond to pulling the coilpack... what does the plug look like on that cylinder?

[BoostFiend510]

Alright im pretty much a noob on cars but i got friends who are pros at this that are helping me out but they dont know alot about the sr ... Im going to check it the o2 sensor and try and get a compression check in a minute and get back to you on that... When change around the coil pack it does the same thing so i dont think thats the problem. Im thinking the ecu could be fried so im picking up one right now and see how that works. Ill give an update in a few

[BoostFiend510]

i have 240 sx sr20 det motor swap.i just bough the car (http://www.240sxforums.com/forums/#)!and im having problems with it that i cant figure out.it has 3 inch dp,boost controller,full coil overs,air filter,boost gauge.
i just changed all four spark plugs and 3 of them at the electrode was melted and gone ? and the last one was perfectly fine.
i installed the new spark plugs the car was running perfect.spooling fine at 9 lbs.it was puurrriinnggg http://www.240sxforums.com/forums/images/smilies/smile.gif
then 20 miinutes later i go home turn her off.and i head out bout 20 minutes later and the car from idle was just misfiring a little bit.didnt think much of it.go down the road a little bit more and it got worst and worst till i had to pull over and it was just misfiring like crazy.i go tthe car home took off all the spark plugs and 3 of them was fine # 1 was melted on the electrode?and full of gas.i put another one in that was good from the last set of spark plugs.started her up and still missing.engine shaking smells like gas rough idle and driving.i test the spark at the coilpack has blue spark.i swapped coilpack from #1 to #2 and #2 to#1 nothing changed.so i kno it not the coilpack.then i let the engine idle with it missing and unplug the coilpack connecter to #1 thats missing and nothing changed in the idle hmmmm weird..i unplug #2 #3 and #4 and all of them changed the idle so i thought hmm short in the wiring for #1.i test the ground power and signal wire and got readying on all of them.im lost and need suggestions.its just drench in gas in #1 and its misfiring and have no idea what to try next,.i went through the process of elimination.so to sum it up.
new spark plugs.
#1 electrode was melted and flooded
#1tested for spark with coil pack.
un plug #1 connecter to coil pack and nothing changes in idle.

[BoostFiend510]

i have 240 sx sr20 det motor swap.i just bough the car (http://www.240sxforums.com/forums/#)!and im having problems with it that i cant figure out.it has 3 inch dp,boost controller,full coil overs,air filter,boost gauge.
i just changed all four spark plugs and 3 of them at the electrode was melted and gone ? and the last one was perfectly fine.
i installed the new spark plugs the car was running perfect.spooling fine at 9 lbs.it was puurrriinnggg http://www.240sxforums.com/forums/images/smilies/smile.gif
then 20 miinutes later i go home turn her off.and i head out bout 20 minutes later and the car from idle was just misfiring a little bit.didnt think much of it.go down the road a little bit more and it got worst and worst till i had to pull over and it was just misfiring like crazy.i go tthe car home took off all the spark plugs and 3 of them was fine # 1 was melted on the electrode?and full of gas.i put another one in that was good from the last set of spark plugs.started her up and still missing.engine shaking smells like gas rough idle and driving.i test the spark at the coilpack has blue spark.i swapped coilpack from #1 to #2 and #2 to#1 nothing changed.so i kno it not the coilpack.then i let the engine idle with it missing and unplug the coilpack connecter to #1 thats missing and nothing changed in the idle hmmmm weird..i unplug #2 #3 and #4 and all of them changed the idle so i thought hmm short in the wiring for #1.i test the ground power and signal wire and got readying on all of them.im lost and need suggestions.its just drench in gas in #1 and its misfiring and have no idea what to try next,.i went through the process of elimination.so to sum it up.
new spark plugs.
#1 electrode was melted and flooded
#1tested for spark with coil pack.
un plug #1 connecter to coil pack and nothing changes in idle.

just tryed what u sayed.spark is consistent...
i swap fuel injectors from #1 # 2 nothing diff.i check the power on number one and ground everything is ok?
only #1 when u un plug it does nothing changed to the idle.this is annoying and car is flooding with gas in #1 cylinder.so any more help.ecu could be bad?

[fcdrifter20]

Was your idle always high like that? If not you mite have a leaky injector. Check resistance on the injector, if its wiith in specs, pull it and check to see if you got a busted o-ring

[DailyDrivenS14]

dont have to be a pro on an sr to narrow the problem down bro! you've found which cylinder it is, then you said that it was getting spark... if its getting spark, check for fuel... swap the injector to another location and see if the problem moves with it. That will either eliminate the injector or tell you that the injector is the problem. But do a compression test too if you have the tester!

[Hashiriya415]

I can help you diagnose if you want to come to SF. PM me

[BoostFiend510]

dont have to be a pro on an sr to narrow the problem down bro! you've found which cylinder it is, then you said that it was getting spark... if its getting spark, check for fuel... swap the injector to another location and see if the problem moves with it. That will either eliminate the injector or tell you that the injector is the problem. But do a compression test too if you have the tester!

I dont have a compression tester so i havent done that yet... BUT i did switch the injectors and now the injector that was in cylinder 1 is leaking crazy. So i guess the O ring is done? Its late so im going to work on it when i have light and see what happens next

[fcdrifter20]

I dont have a compression tester so i havent done that yet... BUT i did switch the injectors and now the injector that was in cylinder 1 is leaking crazy. So i guess the O ring is done? Its late so im going to work on it when i have light and see what happens next


make sure you lube those things up good before you put them back in

[BoostFiend510]

:rant2:
Alright.... Sooo today i finally got a hold of a compression tester and guess what i find??? A big 0 in cylinder 1! Yea... Everything else was fine. But i guess the seals are fuked. Which really pisses me off because i was told that this car was just rebuilt and had 4000 on it as of the rebuild. And when i pull off the valve cover it doesn't look like he did shiiiiet. Barely 3 weeks and the car is done..

[DailyDrivenS14]

sorry to hear that bro! i had a bad feeling that it was the problem...