Truck not idling worth a damn...

[neonhomer]

I don't what the issue is, but I think it might have something to do with the P0300 code I keep getting.

When sitting idle, either in Park or Drive, the truck feels like it wants to stall. RPM is around 500 or so.

I changed the plugs and wires, and cleaned the MAF sensor, but still it doesn't idle right.

I tried uninstalling the tune and ran it for a little bit, but it still does it. I don't really think it is the tune.

I am trying to figure this out, as it is driving me nuts.

[CANUCKPREDATOR]

p0300 is a random misfire.
don't know if you Predator will do it, but hook up and monitor for misfires to see which cylinder(s) is doing it. might be distributor cap or coil.

[Yknhotshot]

I had this problem in my 02 silverado and it was the intake gasket leaking after I replaced that it runs just fine

[neonhomer]

The new 7193 does have logging... Regardless, I monitor the misfires and it shows misfires across ALL cylinders.

There is no distributor cap... it's direct ignition. If it's the coils, then it's all eight of them.

I've heard the intake gasket theory, but I really hate to do that. One other thing is that I am loosing coolant... bit by bit. However, from what I read, the gasket leak only affected the front two or rear two cylinders... not all 8.

[CANUCKPREDATOR]

Any sight of coolant leaks on the outside of the block? Pull your plugs to see if they are clean. If you loosing coolant into the cylinders, you'll see it on the plugs.

[neonhomer]

When I changed my plugs, I dont think I saw any traces of coolant on them... I did see some residue from fuel additives (I was using Lucas fuel system treatment in each tank for a while), but no coolant.

I can't see any external leaks, but I was told they did upgrade the water pump gasket, as it was a common leak point. From what I remember, they said the leak is in a spot where it evaporates really quickly, so it doesn't drip on the ground.

Besides, if I pull my intake, I want to change the cam..... and I can't afford that right now!

[pheonix311]

id say check your injectors to make sure they are all spraying at optimum range

[neonhomer]

Please elaborate....

[pheonix311]

if the injectors or your feul rails have a slight clog in there they wont spray consistently. ive had inconsistent feul cause misfires across all cylinders before.

how many miles are on it and do you EVER add feul additives?

[neonhomer]

I used to run Lucas Fuel system treatment all the time. I was getting a little better fuel economy with it. I quit using it because I keep forgetting to go get another gallon to refill my little bottles.

Truck has about 90,000 on it, give or take a few.... mostly highway miles.

That could be possible... as the `04 pickups didn't have fuel filters per se.... they only have the fuel pump sock in the tank.

[mikel]

Are all of the O2s reporting properly?

[neonhomer]

Dunno. I will plug in on my way back from lunch and check it out.

If it's tune related... It's Lew's fault!!! LOL

[06MonteSS]

bastard...


NO IT AIN'T...

hahahahaha

[neonhomer]

LOL...

What am I looking for in the O2 readings? Can't log right now as my computer is on a job site...

[06MonteSS]

make sure they're at least all reporting values, and are not just dead and not showing/reading anything..

and make sure they are fluctating, not just reading a steady number... they should jump around...