What size gap should I put my NGKUR5 at?

[saeedbeck]

I have a rough idle and a dancing tach. I have replaced the sparkplugs, wires, cap, rotor, distributor, cleaned the IAC, changed the fuel filter, changed the fuel pump, checked the timing, replaced the vacuum lines and I still have a crappy idle. I rev the engine and it will vibrate on the way up and almost die on the way down. I don't know what the problem is but I noticed that I have seen posts where the gap for the spark plugs is .35 and also .32. Can some one tell me which one it is so I can ease my troubled mind? Thanks.

 

[MRKING]

Re: What size gap should I put my NGKUR5 at?

Is your truck stock , or modded ?

 

[saeedbeck]

Re: What size gap should I put my NGKUR5 at?

It is a stock motor.

 

[MRKING]

Re: What size gap should I put my NGKUR5 at?

It is a stock motor.

Gap all plugs @ .035". Tighten the gap .032"for higher boost and more Fuel Pressure, or when running alky/water injection.

Thats a copy/paste from sytyauthority.net .

 

[saeedbeck]

Re: What size gap should I put my NGKUR5 at?

Oh well. That's what I have them at now. My problem must be somewhere else. I wish I knew where. I will try checking the grounds at the back of the head and maybe the knock sensor. I am leaning towards a compression check, but I am afraid of the results. I can't imagine that a burnt piston would make my idle fluctuate the way it does though. It is always crappy, but sometimes when it is cold or warm, I will start my truck and it will miss really bad like one piston isn't firing and sometimes it will run pretty smooth except for a slight vibration. I have checked my injectors and had them cleaned so I have ruled them out. I checked them by raising the fuel rail and then disconnecting one at a time to see which one made no difference. It seems a little unconventional to check them this way but I don't know any real tests to do on them otherwise. I checked the egr and it seems to be doing what it is supposed to do. I give it a sqeeze and the engine runs real bad. I have heard on this sight that tach flutter is ignition related, but I have changed everything in the ignition except the computer. I don't know where to go next.

 

[MRKING]

Re: What size gap should I put my NGKUR5 at?

Is your timing at 0* with the tan wire under the pass side dash unplugged ? Did you just buy your truck recently ?

 

[saeedbeck]

Re: What size gap should I put my NGKUR5 at?

Bought my truck in November. Tan wire was disconnected when I set the timing, and when I reconnected it, the timing went up to around 15.

 

[saeedbeck]

Re: What size gap should I put my NGKUR5 at?

The thing is, I have been on this sight for a while. I have been researching this problem for a long time and everytime I try something, I will spend time on it and when I am done the my truck will run the same.

 

[It's just a six]

Re: What size gap should I put my NGKUR5 at?

Hi all,
I was wondering why you guys are running a hotter plug, the NGKUR5.
You guys should go w/a higher number for a colder plug.

 

[MRKING]

Re: What size gap should I put my NGKUR5 at?

Hi all,
I was wondering why you guys are running a hotter plug, the NGKUR5.
You guys should go w/a higher number for a colder plug.

I am running the ngk-tr55's on my vortecs and I agree once modded , you should go colder with the higher boost . There were a couple threads recently by 2 diff members with the same issues. Other than checking your egr , iac , and all ignition components , I havent had that problem with my truck and cant say "for sure" what it is .

 

[gjp]

Re: What size gap should I put my NGKUR5 at?

Sounds like my problem I have been having. Check all the injector plugs and clean them out. Check the injector harness plugs too. How do the plugs look when you pull them?? How many miles on the truck?? I would do a compression test and even a leakdown test. If anything it will rule out most internal problems. Mine only missed when my truck gets hot. I went through and cleaned all the connections, grounds on everything in the engine bay. for the last few runs it has been fine. A slight miss is common at idle. as far as gap.. you should be fine @ 34-35 stock boost. 30-32 with 3 bar and more boost.I am running 32 and my truck likes it. .

 

[2fast4u]

Re: What size gap should I put my NGKUR5 at?

The thing is, I have been on this sight for a while. I have been researching this problem for a long time and everytime I try something, I will spend time on it and when I am done the my truck will run the same.

Ever figure out the problem??

 

[supersports10]

Re: What size gap should I put my NGKUR5 at?

this is like the 4 - 5 truck i have seen on here, where i think it is the reluctor ring in the distributor that is cracked.
try replacing your distributor with a known good one.

 

[AutoVation]

Re: What size gap should I put my NGKUR5 at?

Was this problem ever resolved?

 

[2fast4u]

Re: What size gap should I put my NGKUR5 at?

Was this problem ever resolved?

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