[mcqueen]

For the past few weeks my detonation issues were mostly resolved. I went from having problems with it every 2-4 start ups to having problems every 15-20 start ups and it was mostly on really cold nights that it happens. Well for the past 2 days I've noticed a huge lack of power right after I start the car and for a few minutes following. From 1300-3000 RPM it feels like detonation, but no where near as bad. Just sluggish. Once it hits 3000 RPM it's like the engine got a swift kick in the ass and I'm off and going. When I shift up, I have the same loss of power until 3000 RPM again.

I've got brand new spark plugs installed and I know people have had issues with NGK, would something like this be a similar problem? (they ran fine until 2 days ago, so I don't think they're the issue) Spark plug wires changed yesterday and didn't help. Found the hose that attaches to the CAI was dry rotted too badly to stay connected, put a new hose on and that didn't help.. I've still got to change the fuel filter and clean the MAF/TB when I can get some time to do it.. I'm at a loss as to what would be causing the problem besides my timing which I need to change a bit (it came a little advanced from AM).

[08v6stang]

maybe vtec is kicking in yo!


.......lol, i have no idea what it could be but i had to say that.

[mcqueen]

If only I was driving a Honda

[b1gdaddy98]

I'm posting because I want to know also, since mine just started to bog down some on start ups...so yeah!

[mcqueen]

Next week when the gears and such go in I'll need to change the tune, so I'm going to reduce my timing a bit and see if that helps at all. I would think the timing on yours (b1gdaddy) would be fine though. May be something else but I still wanna try reducing the timing..

[Rich J]

Sorry for asking but what is "detonation"

[b1gdaddy98]

whew....go to search and type in detonation...u will find so many threads on it...it's not a good thing

[mcqueen]

Detonation Explained

[b1gdaddy98]

^^^^ +1

[Rich J]

So if I read it right, a form of detonation could be like when accelerating slowly the car kind of "kicks" forward quick at low rpm's? or is this something else?

[9986paulk]

Originally Posted by demon_54 So if I read it right, a form of detonation could be like when accelerating slowly the car kind of "kicks" forward quick at low rpm's? or is this something else?

yea, that could be detonation. Or just a misfire, I also have that problem with my old truck. No detonation anymore, but still does those real quick little jumps you can feel while like going up a hill. detonation itself is when the fuel explodes, for some reason or another, before the piston gets to the top of its compression stroke.

[01VBmustang]

Check your plug wires.

My car used to buck/misfire at low RPMs and it was because or a dry rotted wires. I changed my wires and coil pack and the issue went away.

Worth a shot.

[mcqueen]

Originally Posted by 01VBmustang Check your plug wires. My car used to buck/misfire at low RPMs and it was because or a dry rotted wires. I changed my wires and coil pack and the issue went away. Worth a shot.

I just changed the spark plug wires a few days ago. I'll check to be sure the boots are still in place properly. The connectors to the coil pack are bothering me. They're clipped on so when I pull on them they don't budge, but when I push them they slide in ever so slightly.. I might end up changing the coil pack soon. New gears go in Monday so I'll be changing the options on my tuner and I'm going to reduce the timing and pray it helps. Not getting my hopes up though.

[Vapor7]

You have DPRC 'dual plane runner controls' in the manifold. It sounds like both are stuck open which would make it run lean at low RPM = below 3000. The valve may be freeing up as the motor warms. If you are unfamiliar with DPRC it is much like another throttle body inside the manifold. Each cylinder has two runners. One longer and one shorter. The DPRC shuts off the shorter one at low RPM but opens it at higher RPM as needed.
I first ran across this nonsense on a 2002 Cougar and they are a pain BUT it was a good idea for low end torque. Don't ask how to fix them. I just replaced the whole unit. I believe this was a Cosworth idea.

[mcqueen]

When you say manifold, would it happen to be the upper intake manifold you're referring to? So swapping for a new manifold or even a Windstar could possibly resolve the issue?

[mooses]

Originally Posted by mcqueen When you say manifold, would it happen to be the upper intake manifold you're referring to? So swapping for a new manifold or even a Windstar could possibly resolve the issue?

He's talking about the IMRCs, which are in the lower intake. They open up somewhere around 3k I believe. I wouldn't think that they are the problem since people have deleted theirs and don't complain about being sluggish below 3k.