#1 cylinder, spark plug killer

[biglipzit]

Ok here is the problem. Couple months ago after running on the track i developed a bad miss and when i got around to removing the spark plugs the number 1 cylinder plug which was a champion platinum had the whole centre electrode burnt out. I replaced the plugs with more heat resistant ngk iridiums and today after running on the track it developed the miss again and upon removing the number 1 plug it was immediately noticeable that the ceramic protector around the centre elctrode was burnt off and the end electrode was melted out of shape. Why is it this cylinder that destroys spark plugs? I think it is running lean for some reason and developing too much heat but wouldnt this damage the piston before the plugs? I am a bit lost when it comes to rectifying the problem.

[Carl H]

that looks more like detonation or possible piston contact.what plugs are you running?heat range?

[biglipzit]

How could it be piston contact if the end electrodes do not bend in and the lower center electrode only gets most of the damage and how can detonation occur in only 1 cylinder? The chances of it occuring and damaging 2 spark plugs on the same piston are very slim.

[Joe]

no possible way thats piston contact

thats SEVERE detonation, move the injector to another cylinder and see if it keeps happening to that cylinder.

[biglipzit]

Why would that injector cause severe detonation? Running to lean? Maybe that cylinder has a clogged injector. How can i check for this and how do i clean it if it is blocked?

[Joe]

Why would that injector cause severe detonation? Running to lean? Maybe that cylinder has a clogged injector. How can i check for this and how do i clean it if it is blocked?

exactally, if its a clogged injector or one that is sticking it can cause this. the TRUE way to clean an injector is to send them somewhere like RC engineering and they will clean and flow it.

i reccomend just switching the injector to another cylinder and while doing so, look at the injector. look at the nose and pintle (needle in the center) look for deposits or damage. do not apply voltage to the injector to check it. it could fry it.

[BoostFab]

that's straight up detonation. are you using the right heat range? i'm not a big fan of those iridium plugs when boost is involved. NGK 3330 all the way.

[Nameless EJ6]

Get them injectors cleaned up.

[biglipzit]

How does switching the injector to another cylinder help and i live in the caribbean, it aint worth sending the injector up to america to get cleaned... Is there no way to clean it myself? If not what is a good upgrade for the rb20? 550cc from an rx7?

[goofynick6]

Switching it to another cylinder will show if the injector is in fact the problem. If you move it to cylinder 2 and #2 plug looks like that after running at the track, then the injector is at fault. 550's are a god upgrade if you're wanting 400whp, otherwise some 440's would be a very nice upgrade.

Nick

[Joe]

Switching it to another cylinder will show if the injector is in fact the problem. If you move it to cylinder 2 and #2 plug looks like that after running at the track, then the injector is at fault. 550's are a god upgrade if you're wanting 400whp, otherwise some 440's would be a very nice upgrade.

Nick

ding ding ding

it will show you the exact problem, think of it as a troubleshooting method.

[biglipzit]

lol spark plugs aint cheap here!!! Well i guess i have no choice but to do that. Thanks for all the help guys. I guess that is the new plan.

[Joe]

stop running those fancy iridiums, a 2$ NGK copper plug runs better on RB's anyway

[biglipzit]

ngk coppers still cost in the range of $4.50 - $5.00US here...

[Joe]

still a buttload cheaper than the 20+ dollar iridiums then huh?

[Nameless EJ6]

If you don't want to send them off, do run some injector cleaner through your fuel.

[biglipzit]

that crap doesnt work in the fuel, i am using octane boost with injector cleaner plus i ran injector cleaner through it last week. I am gonna remove that one and apply the voltage to force the solenoid open and use a spray bottle to pump injector cleaner directly through the injector and see if that helps...

[Joe]

DO NOT APPLY VOLTAGE TO THE INJECTOR you WILL destroy it.

injectors work off very very short electrical pulses, im sure you have heard the term duty cycle, applying straight voltage holds the needle open wich frys it.

napa here in the US sells a special injector cleaner, it actually hooks to the fuel rail and runs in with your fuel. it works very well.

[biglipzit]

Can you link me to a pic of it so that i can check napa here for it and see if they might even order it from america for me.

[Slo_240sx]

Don't switch the injector to another cylinder. Okay so hes running lean and detonating, no need to switch it to another cylinder and grenade that cylinder also. First thing you need to do is to check to see if your injectors are getting the ground pulse from the ECU. Goto a parts store and ask for NOID lights. They are little lights that hook up to the injector harness and light when they are pulsing off of the ECU. take the injector plug off put the noid like in and crank it. If it pulses the next thing to do is to pull the injectors with the rail still connected. Check what wire is ignition power and which is the ECU ground. Then you can quickly TAP that wire to ground and the injector will pulse with the key on. Make sure you have the right wire! Check for 12v power on one of the wires and the other wire will be the ground. After you tap that wire to ground with quick taps look at the spray pattern. If you do not like that method you can have someone lightly tap the key instead, not starting the engine, and look at the spray pattern then. If it does not spray then you have an open in your injector. Take an ohmmeter and ohm the injector out. It should read continuity. If it doesn't the injector is bad.

DO NOT APPLY VOLTAGE TO THE INJECTOR you WILL destroy it.

injectors work off very very short electrical pulses, im sure you have heard the term duty cycle, applying straight voltage holds the needle open which frys it.

Injectors do work off of electrical pulses (Duty Cycle) but 12v Ignition power is given to them with the key-on. That does not hurt the injector. It is the GROUND pulse from the ECU that opens them. Grounding them will not hurt them unless you hold it for more than 5 seconds. The timing of the injector is known as "pulse Width" which is how LONG the injector stays open not how much the injectors open. Injectors always open the same amount its the time they stay open that determines how much fuel is given. The injectors practically stay constantly open under WOT, so holding them open won't hurt but I recommend you don't do that anyway.

Try all of that first then get back with us.-Alex

[Joe]

5 seconds is a lifetime when you are dealing with something that opens and closes in a milisecond based timeframe. even at WOT an injector is never always "on", theres a specific word for that when you go above 85% duty cycle that i cant remember for the life of me. its very bad to have happen.

[Slo_240sx]

Of course I agree I wouldn't hold it for me than 1 second. I'd just tap it to ground real quick it see if it were firing. I was just giving him a ball park to diagnose with.-Alex

[goofynick6]

The 85% duty is the limit because MOST injector's spray pattern goes crazy over that percentage, plus you are nearing the limit of your fueling and don't want to lean out with a boost spike or something.

I have a set of stock rb20 injectors lying around in a box collecting dust if you want to pay for shipping you can have them.

Nick

[Wulfgang]

Injectors are simple solenoids. Like relays. Hooking them up to a battery and leaving them there all night will only make them warm. Would you expect your car's relays to all "burn out" if you leave your car running for more than 5 seconds? No. They simply do not pull enough current.

Try it and see.