Fuel issue
 

I just installed 1680cc with a rail in my secondaries with a aeromotive fpr I left the primaries stock. I was only getting 20psi fuel pressure so I re-wired my fuel pump and that fixed my fuel pressure. While trying to tune it on the dyno I drop to about 10psi fuel pressure at 6k rpm. I have a wal boro 255 fuel pump, think its bad? What else would cause this??

Anyone?

Is the vac line connected to the FPR loose? Where is it tapped also. Could be the pump also, if you have another known working one to swap I'd try that.

Side note, who's tuning it? Ziptied?

Yeah the vacuum line is tight and I used the nipple that you use for the stock fpr. Ziptie is the shop tuning it, I bought a data loggit and gave it to them so they can tune power fc's now.

Shouldn't be a issue with the FPR then. What's your base fuel pressure at idle? Was the FP ebay Walbro? I've heard bad experiences with those.

That's awesome of you to buy them DL. I have DL but lack the time and the advance skills to do the job; so I've been debating on taking my FD to them. I know they've done only a few rotaries but Christian@COBB trusts them.

My brother gave me the walboro so I'm thinking that's the culprit. My fuel pressure couldn't be adjusted and was stuck at 20psi no matter what I did, so I rewired my pump and that fixed it. Hopefully it's just my pump an not a restriction in the line.

Yeah they're pretty good with tuning

Is your FPR adjustable? I'd assume even with a failing/low volume pump you should be able to fluctuate the pressure some.

Yes it is adjustable, but how am I going to adjust it when I'm loosing it at 6k rpm? Unless at idle I jump it up to like 60psi

I misunderstood your last post, thought you meant it's stuck 20psi regardless. Honestly sounds like pump issue then. I'm not aware of your setup but you can get supra pumps for cheap.

Stock simplified sequentials, 1680cc sec and stock primary. I want to try and hit 300hp. I might not make that but I'll be happy with what I get once its tuned.