OK, I have a lean/flat spot/skipping problem on what I would like to call project 002. Car is equipped with Acell DFI and JE pistons and crower rods. Car is also equipped with standard msd dis-2. At 5K, the car seems to hit a bad spot (pegs lean and looses power). after 5k, it pulls again without a problem. The car has standard sized spark plug wires. The problem isn't fuel map related (it happens a tall different boost levels), and I seriously doubt it is fuel pump or regulator related (it still has a good A/F ratio from 6 to 15 psi). Has anybody ever had this kind of situation, and was it the spark plug wires. this car is also equiped with new ngk plugs.

bring it on............

Have you datalogged your sensors?

I've heard of similar stuff with the 4g63 crowd at a certain RPM point feeling that "dead spot," as it was datalogged and revealed.

I didn't stick around to see what the causes and solutions were, but as you may guess, it probably was fuel, spark, or air related.(IIRC, there was even a yahoo group that was created to dsicuss it) I would work from those basics, and try and get some datalogs comparing your timing and O2 along a graph and see what it look likes.

Personally, I haven't heard of any such problem being 420a-universal.

I had the same problem last week.It turned out to be lean at a certain rpm/s where I was getting the "dead spot",although egt's where cool and a/f was alright.Same thing,power from 1000-3500 rpm,dies from 3500-4500,4500+ goes back to full power.I richened it out and it got rid of it.

It could also be too rich. I've had that before. Mine was always at 4k.

also check your map sensor voltage. What fuel cut bypass method do you have installed? HRC FCD? VC-1/2?

How is your timing? The timing may be getting pulled and that flat spot is the short time before being fixed by the DFI.

This was sort of my thinking as well.. datalog it, and see what the timing advance is doing.

Things to note:

002 runs an accel DFI. It does not need any help with the stock map sensor since it uses its own 3-bar. No fuel cut issues.

Timing is handled by a DIS-2 retard set to 6deg at 7k, NGK BKR6E gapped to .030 (unless that has changed recently - Armond?), NGK wires.

plugs gapped to .035 currently. I didn't feel the gap would have to be closed very much at a low boost setting especially with the msd ignition. I will try a new set of spark plugs this weekend, and if that fails, I will have to purchase a cheap laptop and datalog it to check the ignition timing. Thanks for the responces.

bring it on............

i had same exact problem. turned out, plugs were screwed.

I think .035 would be too much. I consider .030 already pushing it. It would be nice if that is all it is. I wish I could send you one of my laptops considering I have two. :(

With the MSD, shouldn't you be able to actually gap your plugs a little higher? No experience here, but I thought w/ a more powerful ignition, logically you should be able to make the gap larger...basically saying that .035 should be fine since that's what's recommended w/ the stock ignition system and the same plugs.

A .030 gap is already larger than I would recommmend without an ignition. I would gap to .025-.028 without one. I think that at the high end .035 is still too much. It could just be my wires though. I am still using the stock 7mm sized NGK wires. I felt they are enough, but maybe I need something larger?

You "can" still send me one of your laptops ;). (as long as it has an rs-232 port ;))

A.D.P.
bring it on............