car bucking inbetween 3-5rpm and lumpy idle (more)>>>>>

[Nismo_180sx]

SR doesnt want to hold an Idle revs up and drops and dies. black smoke out of the exhaust. I checked all hoses for vacume leak but didnt find any. fuelpump is clicking and fuel isgetting to the rail. coil packs are tight and secure. checked MAFS plug for corrosion along with injector connectors. I'm stumped! any ideas or things to check would be greatly appreciated.

Thanks..........Jeremy

[jdm_master_X]

maybe u might have oil leaking into the cylinders. u should do a cylinder leakdown test and a compression test. those two tests will tell you everything.

black smoke huh? u sure ur not leaking boost via intercooler or turbo? maybe ur turbo ingested something nasty. thats what happened to me anyway.

[9240sx]

Sounds like a Boost leak and or Vaccum leak.Did you check all the hose coulpers and the intercooler,And what kind of BOV you running??

[Nismo_180sx]

yeah, to be safe I'm going to replace all the vacume lines even though I went through the engine and checked them for cracks and loose clamps. as far as BOV goes i'm usning a HKS Super sequential. and I've got a cap on the GReddy intecooler piping and is sealed pretty good down where the factory BOV recerculates.

[Nismo_180sx]

the nightmare that is my engine bay>>>

[9240sx]

You sould also try to recircluate that Bov.it will help alot with you idle and backfiring,And pretty much makes the car run alot better..I know HKS sells the fitting for it..

[travisn]

i will bet 50 bucks that if your car bucks in the 3-5 grand range your plugs are bad. happened on my escort and my buddies blazer. restored a lot of power and made gas mileage about 5 mpg better after i fixed it.

[Nismo_180sx]

I hope not I just replaced them this past weekend with NGK R iridiums.

That would totally suck! $60 gone that quick.

[travisn]

well black smoke means running rich, and too much fuel will hurt performance, so maybe leaky injector. my car ran fine until i got on it then the black smoke would appear and it was bc i had a rip/burn through in the first coupler comming out of the turbo. took me a while to find bc you have to look up and over/around to see the back side of that coupler. but if it does it when cruising under no load or boost then its a fuel/spark problem.

[sr_powered]

try recirculate ur BOV. mine was having the same problem, and after the recirculating hose was connected to the BOV, my engine ran perfect, has better gas mileage, and no more back fire!

[Nismo_180sx]

was running fine before. and I didnt have the BOV recurculated. Like I said I was on my way to work on the interstate and then all of a sudden the car was jerking above 5krpm and at lower rpms in lower gears. and it was smoking bad and popping. its deffinately an air/fuel problem I've got SRtalk and when I get a chance I'll hookup my laptop to the 240 and see if it throws any codes and check sensor readings.

"crosses fingers"

thanks for all the input.........Jeremy

[Nismo_180sx]

performance isn't what I'm worried about. I'm just trying to get the damn thing to hold an idle and run right. not lumpy and dieing. I'll also check the plugs to make sure they aren't damaged. damn iridium tips are so fragile one of them could have been chipped and broke off after firing.

[travisn]

off topic but whats SRtalk and where do i get it??

[Nismo_180sx]

SRtalk is a diagnostic software that plugs into your car like the nissan consult system that they use at the dealership except you use your laptop or palm pilot (my case laptop). you have to get a special cable that connects from the port on your car to a converter connector cable that connects to the end of the your laptop. its a good software cause if your car is throwing codes it will tell you the code and what it means. (beats trying to read flashing lights and then looking the code up in your manuel or online. and it also tells you output readings of all your sensors and a lot of other stuff. Its free too! I used to use a similar program on my 300zx twinturbo called Ztalk and also Conzult.

SRTalk software>>>http://www.zcontrol.net/downloads.asp

converter cable>>> RS232 Cable (searh on yahoo or google)

laptop to car port consult cable (PLMS cable)>>>>http://www.plmsdevelopments.com/consult_if.shtml

PLMS I believe also sells the converter cable. It has to be a certain one cause I found out the hard way after trying different cables from bestbuy and circuit city.


Modified by Nismo_180sx at 7:33 PM 3/29/2006

[Nismo_180sx]

Travis,

looks like I mite owe you $50 man. LOL!

after reading your post and all I was like well maybe I gapped them wrong...... So I called Enjuku racing where I got them and asked Teddy, what are these plugs supposed to be gapped at man. He replys...they come pregapped and you're not supposed to gap them cause you could break the fragile iridium tip. I reply "FU*K" thanks buddy.

I pulled the plugs when I got home tonight from work and sure enough #1 cylinder tip is shorter than the other three and black as night from running rich in that cylinder.

"dumbass"

hard lesson learned here folks.......Iridium plugs....."pregapped"

I'm gonna go a head and replace all 4 since they are nasty from running rich and just clean the salvaged ones up for emergency spares if needed later.

Thanks for the input Travis. Thats why I like forums like this....it allows you to have multiple people help trouble shoot with you. Or someone else has had happened what you are experiencing and can give you a quick answer and what you need to do to fix the problem and save you a lot of time.

Thanks again......Jeremy Heath

Modified by Nismo_180sx at 7:56 PM 3/29/2006

Modified by Nismo_180sx at 7:57 PM 3/29/2006
Modified by Nismo_180sx at 7:58 PM 3/29/2006

[Nismo_180sx]

picture of the bad plug compared to one of the three good plugs. notice the gap and tip difference.

[travisn]

thats awsome man, glad i can help. lemme know how it works out...

[Nismo_180sx]

Travis,

I installed the new plugs on Friday and the 240 runs like a champ again. I went with a 6 heat range this time instead of 7 like I had in there before.

Thanks again bud.....Jeremy