Is the slow car slow through the entire rpm band? My car was dead, badly, right in the middle of the power band like 2000-3500 RPM. If the slow car is dead all the way through matters. Below 2000, from what I have read, the ALDA will help. My crack was nearly invisible, and made no noise per say. Only way I found it was I noticed soot and investigated. Now the car feels like a gasser and pulls hills without downshifting.

crack in what was barely visible?

My sluggishness is not at its most noticeable from a dead stop. It's most obvious when I'm traveling at highway speeds and then accelerate. Again, I ultimately have no difficulty accelerating....it's just that the pedal has to be depressed further for the acceleration to kick in. As compared to my 92, this is what creates the impression of a lack of responsiveness.

I started this thread http://www.peachparts.com/shopforum/diesel-discussion/297342-300sdl-gets-stuck-60mph-2.html because at about 60mph the car was gutless and smoked a bit. would not pull hills unless I floored it then it would go. Above 3500 rpm it felt fine. below 2000 it seemed normal. Mine has the two piece exhaust manifold with the expansion connector. It was extremely difficult finding the crack.

Replaced your fuel filter lately?

Yes....although I realize they can clog at any time. My thought is that, if my problem were a clogged fuel filter, I wouldn't have good acceleration regardless of pedal depression.

.... your still discussing this? adjust your alda or forget about the issue. the alda DIRECTLY effects pedal throw to rack throw, that is how it accomplishes it's job. so if they run different pre boost but the same under boost just adjust it.

Percieved Acceleration
 

1.Perform The GSXR Pressure Activated Wastgate Upgrade/Conversion.
2.Get yourself a Boost Gauge and a Stopwatch.
3.Clean out ALL the Tubing to/from the ALDA and Blue Saucer.
4.Clean the Intake
5.Block the EGR ,for testing purposes (Nod,Nod Wink,Wink)
6.Clean and Lubricate Everything in the Accelerator System.

What section of the FSM?

I my experience, a clogged filter is much more of a factor at the higher end, however counterintuitive that might be.

I bet anyone a dollar he has the same crack i had. My symptoms were almost identical and everyone said ALDA. I had to remove the two clamps before I could see the crack. The difference is night and day driving on the highway is now a joy instead of having to push hard on the pedal for every stinkin tiny hill

Can you explain more precisely where the crack was? I'd be glad to take a look. Thanks.

you have a 603 correct? mine has a two piece exhaust manifold. There is a stainless corrugated, flexible coupler between them with two clamps. that is the best way I can describe it. Under one of my clamps was a small hairline crack. I guess under load exhaust would leak from this crack but barely enough to notice at idle. So there was no additional noise. I did a temporary patch and took it for a drive. It was night and day.

No...602. But perhaps similar configuration.

You mean the coupler behind the turbo, toward the down pipe?