280 with Drag Electronis, will not pull past 6000rpm if throttle mashed from takeoff

[Mike Nass]

I have a customer who has just installed a clean, used 280SS, with Drag Electronics on a Cougar Omega... If you accelerate gradually, it will pull all the way up to over 9000rpm with a 26 Yamaha, he's swapping to a larger prop to bring it down a bit... however, if he punches it from about 3000rpm or less it hits a wall at about 6000-6300 and will not run up any higher, it sort of surges like it wants to go but just won't go... if he lets off the throttle lets it come back down to 3000rpm or so and roll into it slowly, its pulls all way up and over 9000rpm... OK guys... what do you all think is going on?

[patchesII]

What ecu? That's an odd problem

[bigbluechevy454]

I would think the ecu maybe the problem

[Mike Nass]

A6 ECU... Also, they checked fuel pressure and it stayed right solid at 56...

[patchesII]

Do you have anyone up there that can check the curve in that ecu or put another one in it. I'm thinking out loud here and maybe RBT will get in here but under full throttle you are operating on the top line or two of the fuel curve. If the box is corrupt sometimes a random number or a few may have some really odd numbers, sometimes may be a 0 where there should be a 145 or could be a 255 where there should be a 145(just using 145 as an example). When you ease into it the motor is still pulling some vacuum so you aren't running off that top load value line. I know it sounds Greek if you haven't seen a fuel curve but there's a chance that could be the issue. I'd try another ecu

[Mike Nass]

That does make some sense for sure... I don't have anyone near who can check the curve or install another one... we'll have to ship it off... RBT, I would be interested in your thoughts?

Do you have anyone up there that can check the curve in that ecu or put another one in it. I'm thinking out loud here and maybe RBT will get in here but under full throttle you are operating on the top line or two of the fuel curve. If the box is corrupt sometimes a random number or a few may have some really odd numbers, sometimes may be a 0 where there should be a 145 or could be a 255 where there should be a 145(just using 145 as an example). When you ease into it the motor is still pulling some vacuum so you aren't running off that top load value line. I know it sounds Greek if you haven't seen a fuel curve but there's a chance that could be the issue. I'd try another ecu

[patchesII]

Is your customer in the States or Canada

[Mike Nass]

he's in Canada... West Coast...

[RBT]

Weird, mike check your pm's

[KEVIN P]

Defineatly an odd problem to have . Can't wait to hear the outcome. This will help in the future I'm sure.

[bigbluechevy454]

I had a brucato acu lose half of the fuel curve. And ran fine but only to like 3000

[Mike Nass]

Thanks guys, Erik I think you hit the nail on the head... we sent ECU off today... we'll see how things are when it returns...

cheers,

Mike

[malexie]

How big is the "larger" prop he put on?

[Mike Nass]

Just to close the Loop, Erik, you were right on the money, corrupt fuel map... not sure how it happened, but sent to Tony Brucato and they found it was corrupt with zero values in much of the map.... he reflashed it and it runs great!

cheers

[RBT]

If it is a Woodward box, they don't seem to like magnets...... Like flywheels