Beretta.net

The car runs okay when cold. Idles fine all the time. It started with a little hesitation when I gave it a little gas at low speeds. It has gotten to the point, I'm cruising at 35mph, I give it a little gas and watch the tach go to 1500 rpm, then it will dip down to 1100 rpm as if I took my foot off but I did not. Then I have to put my foot down more to get it to accelerate. Sometimes, I think I feel a little surging with the stumble.
Sometimes I can pump the gas pedal kinda quick several times, and the car will be fine for a few minutes.
Heavy acceleration seems to be fine.
So I've replaced:
the TPS with an used one as well as a new one.
the MAP with an used one, then a new one.
I cleaned the MAF and then swapped it with one from another car that runs fine and a used one.
another ignition module with coils that I bought off Ebay
New plugs and wires
I checked ohms on the injectors, they are all equal.
I bought a new knock sensor and it seemed to work for a couple weeks.
It does seem to run better if I disconnect the knock sensor but I think I heard a little
clatter during moderate acceleration so I hooked it back up but I backed the sensor out a bit
because I heard if it is too tight it can be reading normal noise as knock.
There is no SES light on
I even put in a spare ECM that was the original.
I put in a new oxygen sensor and then another used one.
I tested fuel pressure and it's about 40 at idle and 45 if I pull off the vacuum line.
Just for grins I swapped the pressure regulator with another used one I had lying around.
I replaced the coolant temp sensor and the IAT as well.
I've checked all vacuum lines for leaks and found only a minor one on the charcoal canister.

I'm wondering if my EGR is bad. Somewhere I read low flow in the egr can cause stumble.
I'm not losing coolant and I think the LIMG were changed by the previous owner.
Anybody got any ideas?

Bang on the converter to see if you can hear loose media. Also it could be just clogged.

Nope, I kick it and I heard no rattling inside. I did have one on another car go one time and I know the
catalyst pieces can clog the tailpipe and choke the engine. Besides, the cars runs fine when I floor it.
The one that clogged wouldn't go more than 20 mph.
To me it seems like it gets air and fuel but after a half second it goes lean.

Not sure what else to check. Did you try some Heet in the gas? Good flow at the tail pipe?
Leaking fuel filler cap or filler neck(they sometimes rust out)? Sure seems like you are losing pressure. Only getting it back after you have built up enough to cover the loss. Or in the case of WOT, getting the pressure back and over powering the leak.

No Heet, we have 10 Ethanol in our gas. I ran injector cleaner through, I have good flow out the exhaust.
I blocked off the intake side of the EGR with some shimstock. It seems to have eliminated the problem.
So maybe the EGR position sensor is off, hence I need a new EGR.
I'll drive it again a few times before I invest in a new valve.

Hear you on that, those things are not cheap!