mudvayne1

I am doing my best to learn how my engine works, but everyday I find something new that I don't know. I've posted questions on here before about my car and I still haven't figured out the problem. I've heard it was the computer or the cam, or even a bad performance chip from a previous owner.

I'm looking at it like this. In my opinion it can either be the fuel, fire, or air. I've ruled out the fuel cause I'm getting 35-40 lbs pressure. I checked my spark plugs after a month's wear and they still look brand new. The distributer plug wires and ignition coil have all been changed and I seen no improvement.

I notice that sometimes my car runs better though. Normally I can never go wide open throttle or even half throttle without it bucking like its starving or flooding. I can't get it to go over 3000 rpms. Everytime I get at the 3k line its like it is governed and won't go higher. But when it is cool outside or wet it seems to run better. I can get it to 4500 rpms in first, but it is real slow with steady throttle.

I stopped up at a chevy dealership to see if they knew where a ford garage was and I talked to them about my problems. They said they wouldn't work on it but they thought it was the cats. I told them I had my cats cut off. They then said it could be 2 things. A bad mass air flow meter or EGR valve. I know what a mass air flow meter is but I have no idea what it does. What does the EGR valve do and where is it at?

What do you think the problems could be? Thanks for the help.

mudvayne1

My check engine light only comes on every now and then and goes right back off so I can't get codes off it. It normally comes on for a few miles while cruising on the highway and it will go back off and continue this.

aode08

when did it start this, and what are all you mods, mechanical and electrical

mudvayne1

It has done it as long as I've had it which is around 3 months. The kid that owned it before me said it started around 5 months ago from right now. He said he was giving it hell one day on the highway and it all of a sudden started doing that. It really sucks because I haven't gotten to open it up yet.

The only mods that have been done to it is exhaust. offroad x pipe and flowmaster mufflers. Other than that it is bone stock.

Cobra77

Also, the check engine light doesn't have to be on for codes to appear. Never hurts to try it.

mudvayne1

I already have. I tried the hand held one they have that hooks under the drivers side dash at quick lube. Wouldn't read the codes.

Joel5.0

DIY KOEO/KOER/Cylinder Balance Self-Test Procedure ....any code registered will be stored in the computer even if the CEL/MIL is off.

mudvayne1

What is the EGR valve's purpose? what does it do?

Cobra77

And throwing some stuff out there....what do you guys think about the engine temp sensor?

And possibly an oddball one, is the spout connector plugged in/there on your car? I'd guess that with that thing not there, it would run a whole lot worse sinse there's no advance.

moterhead

Your last question was about the egr. It's an old tech emission control device. It actually bleeds small amounts of (E)xhaust (G)as into your intake manifold. The (R) is recirculation. An exhaust source for the EGR is not the only function of the crossover in your intake manifold. It also warms your intake system to keep it from icing up in cold weather.

Does the engine have lots of miles on it? If so the timing chain maybe stretched enough to allow it to jump a tooth. You mentioned the previous owner said he was hammering on it whenthe performance went away. This says it was a specific event that caused this condition, not a slow degradation of some part. When a timing chain jumps a tooth, this causes timing to be retarded and will cause lack of performance . Usually also caused the engine to run hot.