My truck has developed a miss at wide open throttle. i changed the fuel filter and it didnt help. The weird part is that i can roll in the gas slowly till WOT and it runs fine but if i punch it really quick it shifts down and starts missing. Could this be a fuel pressure or lack of. Also could it be the hi-lo relay on the pumps? Im open to any suggestions. I have plugs on the way so ill have them out to check tommorow. It almost acts like there is a dead cylinder or two

 

Change the relays and try again, that's a good place to start.

 

I'm betting you will find a toasted plug in there.

Is there a slow RPM miss too ??? MAybe just every once
in a while? That's what mine acts like when I toast 'em ...

 

I swaped the relay. It helped but it still acted up right at the top of third gear. Im 99% sure it is fuel related do to the fact that it starts leaning out when it acts up.

 

that's what mine's doing too, I think

it started several weeks back--sometimes when I floor it it makes a weird "gurgling" noise, and you can feel the loss of power.

...weird thing is it doesn't always do that. I just don't have time to do anything about it right now... but I need to get it figured out soon as well.


-Mike

 

I had the exact same thing a couple of weeks back myself
"gurgling" noise and all.

PLUGS


You'd be amazed on how good the truck can run,
even with numerous bad plugs
As long as something is left, it'll still spark and fire at idle and light throttle quite well, it's only when you stomp it that it'll have Spark Blow Out and miss fires.

In my case we believe we lost one or two @ a month ago on the orig Dyno, (AF was a dangerous 13.8 on the first pull and we heard a stumble) after that I would ocassionally hear a slight miss at WOT, but other than that the truck ran strong as schitt and actually quite well and powerful. Then I threw over 600 HP at it on the street last week, the tires broke loose, it over reved BIG TIME, and I finished um off.

Now that I have new Pumps, new Filter, new Plugs, and a new Tune, I need to get it back on the Dyno



(BTW, first time ever I didn't lose #7 and or #8)

Back to normal now...... WOO HOO

 

Mine also only does it occationally. It worked fine last night



ROB was yours a hit and miss loss of power like mine and red's?

 

Strange enough YES up to when that last one must have melted a lot of the tip off, then I was getting a miss all the time at WOT.

I would imagine Cylinder Temp, Cylinder Pressure, when and how you get on it (from a stop, down shift, from a roll, etc...) would all play a part on how bad you would get spark blow out and or missing when you have just a slightly damaged plug.

AMOF mine idled perfect, and even felt fine when preloaded or power braked, it was only at WOT you would feel it stumble once in a while (AT FIRST, as said once too many go bad, you will know)

Cant say for sure it's your prob, but it's not the first time I drove around quite a while with a bad plug and really didn't know till I changed them.

 

i have some new ones on the way so we'll see monday

 

Mine pulls perfect on the dyno, and perfect on the street, but if you try to run it down the 1/4 on pump gas it studders at the top of 2nd, or 3rd. No idea what is causing it.

I put race gas in and it goes away. I'm not running much timing. Starting to think it could be a valve or a coilpack.

Your problem doesn't sound like plugs, but hopefully it is.

 

i dont either but these have about 10k miles on them along with 4 bottles of juice so new wont hurt


it has ran fine everytime I WOT it today so i dunno

 

Mine does fine on WOT.

But it's when you stay in it for a while, and the loads go up that it does it. My AF is PERFECT when it happens too.

Also, I had to replace my fuel pump relay recently.