i have a gsr and i've been running ngk iridiums for some time now. last weeken i was just checking the plugs and the 4th cylinder plug was melted, only that one the rest is fine. replaced all of them with new iridiums but the 4th cylinder still leans out. the motor runs fine daily driven. when vtec kicks, it smokes but i thought that was normal for some gsr motors. not sure what the problem is cause its only the 4th cylinder thats like this. any thought on this. please help me out. i'll have pics soon

 

The only things I could think of is either a vacuum leak on that cyl's intake or a stuck injector.

Hey, here is another(unlikely but) carbon build up in that cyl only. but that is all I can think of.

Could check compression for c build up. It might show higher that the rest.

 

i looked in through the spark plug hole and it looks wet. it might be oil, but yea i'm going to do a comp test this weeken. how would u check to see of the injector is stuck or not? also, how can there be a vacuum leak for ONLY that cyl?

 

bad injector

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by h22 civic &raquo;</TD></TR><TR><TD CLASS="quote">bad injector</TD></TR></TABLE>

agreed

 

thanks. i'll change the injector this weeken.

off topic. is 310cc injectors enough for a 75shot gsr?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by track_assassin &raquo;</TD></TR><TR><TD CLASS="quote">thanks. i'll change the injector this weeken.

off topic. is 310cc injectors enough for a 75shot gsr?</TD></TR></TABLE>

what dry or wet? I would assume that's ait for a dry shot, as long as it's tuned and you don't have any more stuff on your engine. Wet it doesn't matter how big the injectors are, nitrous kit supplies it's own fuel. You will need a bigger pump though for both kits.

Vaccume leak is possible around the intake runner, you could try to spray some propane around it see if the engine begins to stumble.

Are you spraying on the motor now, or planning too.

 

i plan to use a zex 75 dry. i have a gsr fuel pump and a B&M fpr. will that do? also, i have some z6 injectors around, can i use one of those to replace the bad injector? are D and B series injectors the same?

 

yeah I'm like 100% sure that z6 injectors are the same as gsr. both 240s. ITRs are 280 (I think).

About 75 dry shot, you should prolly invest in walbro 190, and some good tunning.

With that big of the shot I would personally go with dry.

 

alrite, just swapped the injectors. hopes it runs better in a few days.

thanks guys.

 

alrite. its been a few days now and the cylinder still looks like it did from when i started. i will do a compression test this weeken. i know im not going to like it. damm, its 1 week till track day too.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by track_assassin &raquo;</TD></TR><TR><TD CLASS="quote">alrite. its been a few days now and the cylinder still looks like it did from when i started. i will do a compression test this weeken. i know im not going to like it. damm, its 1 week till track day too.</TD></TR></TABLE>

So it still melts the plug?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ABK &raquo;</TD></TR><TR><TD CLASS="quote">yeah I'm like 100% sure that z6 injectors are the same as gsr. both 240s. ITRs are 280 (I think).

About 75 dry shot, you should prolly invest in walbro 190, and some good tunning.

With that big of the shot I would personally go with dry.</TD></TR></TABLE>

ITR is 240

 

the ground is blistering. but i did the compression test and it was good in all 4. but i dont know y the 4th piston still has oily film from what i can see.

 

also check for vacuum leaks. the motor has no leaks. im stump on this problem. may just change rods n pistons.

 

if you got a laser temp gauge try checking the temps at each exhaust runners, see if it's really running lean or is it something ******* with a plug. Possibly even tell at what RPM it starts happening.