I need ya'lls help to find this problem. While the truck is in park and you run the rpm's up to 1500-2000 rpm, the engine starts missing and the tach will loose and gain rpms(moves back and forth and you can hear the engine miss). Above 2000 its fine and below 1500 its fine. WTF? Truck seems to run good while in gear though, but if its missing out of gear, I must be loosing power while driving but just cant feel it. What gives? Could this be spark plug related? All replies appreciated!

 

Are you running a chip? What all do you have on it for mods?

 

Start with the basics. Pull chip and test again. Then plugs. If I were to guess, you might have a bad plug. If your holding idle at a cetain RPM, and you feel a miss every so often, its more than likely plug related. Now wouldbe a good time to upgrade to better plugs if your still running the crappy stock PLATINUM plugs. Hope this helps

 

Madhouse-I have the JDM warm weather program,K&N panel filter, and upper pulley.
Spiro-Thanks for the info. didnt think to remove the chip and test first. Your right, it will not hold a steady rpm between 1500-2000!
Yeah, Im still running the crappy stock platinums! Their fixing to come out though!!

 

Did you notice this after a day at the races?? or after beating on the truck onthe road?? Does it feel fine at cruising speeds above 50 mph??
The only reason I ask is, after beating on the truck for some time, those plugs could melt the tip away in a hurry.

 

Ok, went out and removed the chip,reset computer, the miss is still there, its just more pronounced with the chip. Doesnt miss as noticeable without the chip. But when its installed its alot more obvious!WTF?

 

Spiro-YES!! I made two passes at the track and noticed when I tried to start it for the second pass,the engine wanted to stumble around and acted like it was gonna die! It seems to run fine while driving at any speed,thats what gets me, because in park its missing pretty bad starting @ 1500 rpm up to 2000, but it smooths out after that. It also has a rough idle at times but not always.

 

It sounds like one of those crappy A$$ spark plugs to me!!!!

 

Hopefully the plug is still seated in the head at least...

 

Change those plugs ASAP. It's a burned plug for sure. Be sure to keep track of the plugs so you know what cylinder it is, more than likely #5.
The problem is with the heat range and or A/F ratio. After "beating" on a truck, the plugs generate tons of heat.. A little on the lean side will only emphasize the problem.

Worse case scenerio is that the plug tip could have actually got caught up in the exhaust valve. After installing new plugs and you still have that "miss", it's probably a little worse than just a bad plug Good luck


Here's the only plug problem I have had. This was done after back to back runs, and a chip in the high 12.7:1 A/F ratio.



THE GREEK

 

I have experienced the same phenomenon....twice. Both times it was the intercooler leaking the coolant onto the plugs, which,apparently, coats the plug and makes it miss. Both times I had the i/c repaired,plugs changed, and......... poof problem gone. At one time mine got so bad it would hardly run at all, (especially seems to be enhanced by the chip, and believe it or not, rain.)

Tim

 

Thanks for the help fellas!!

Spiro- Thanks a million!!! I went to sears and bought all the tools to change out those plugs. I had a local parts store order the plugs because no one around here carried the NGK's! They will be here in the morning. I ordered the TR6's part #4177. Hope these are the correct one's. I havent had good experience's with the split fires in my other truck-always had rough idles-but they did help with acceleration.

Thanks again everyone,Ill let ya know how this plug change works out.

 

I'll be very curious if the plugs help. I have a similar problem, doesn't quite sound as bad, but similar. Plugs didn't help. Chip removal helped most of it.

Let us know what happens.

Good luck. Just let the engine cool overnite. Strongly suggest getting a 3" locking extension so that your plug socket doesn't fall off. If you don't get one, remember my words when you're changing the rear plug on the passenger side!!

 

Just take your time the first time out changing the plugs. Remember......our heads have only a few threads that hold these plugs in, and their ALUMINUM to make it worse. With all EGR equipment in the way, it will be a pain in the A S S , but it needs to be done.
Here's something.... Ask your TUNER if they have the EGR system off. If so, you could remove all that plumbing out of the way for the next time around.
I know for a fact that most tuners do this because I have requested it since 1999, and it helps with keeping the heat down to a minimum. Chances are with your JDM "warm" chip, it has this done.

 

Be sure to use electrical tape on the spark plug socket to the extension. It will make pulling the socket off the plug alot easier when they are installed.