Alright I have a 95 Z28 with a cc306 cam and supporting mods and a mail order tune from MadZ28. The car ran great all summer no issues, now last week I decided to install a Racetronix pump and hotwire kit since I am almost finished with the nitrous kit. After install it smelled rich/felt rich so I pulled the plugs and they were way rich, to the point that fuel was still on them. Do I just need a retune???? I really don't have enough time for a dyno session this season being in Minnesota so I would like a quick bandaid fix so I don't break anything. (car is sitting until this is solved) Also will add I did read the plugs before the install and they looked normal.


Thanks for the help

Just checked madtuner.com also they no longer do lt1 stuff

 

Yea my last high-flow pump lasted less than a month. Just too much fuel recirculation through the return line. Had that gas smell too many times - usually when parking. Went back to stock capacity/style pump.

I suspect hi-flow pumps are tough on entire fuel sys - evap controls, regulator. And i dont need a highflow for my combo. If i did then i would consider dedicated fuel supply and return lines - but i still dont know what to do with the additional vapor produced.

Nothing wrong with the hotwire kit as that will help any pump.

 

If you had it dyno tuned based off of a crappy dead stock pump, then perhaps. But, regardless, the fuel reg should maintain the same pressure regardless of flow at idle. So I would look elsewhere before saying the added fuel flow is causing any of this.

My current pump is roughly 115 gph, compared to a 255lph which is 35gph area, and I have no issues with fuel smells, stock hard lines under car and stock fuel filter etc. Not sure I would chase down that avenue of thought.

 

OP, check your fuel pressure to confirm it is within spec

FWIW I have run a 255 for at least 10 years on a mail order tune. Tuner assumes my FP is in spec and it is

you can get a adjustable FPR...but a functioning stock one should maintain the correct FP

 

Stock pump only had 24k on it, I did a fuel pressure check on the new pump and it reads 48psi idle and around 45 when I rev it up. Could my stock fpr have gone bad?

Also noticed the gas tank holds a lot more pressure than it used to. Evap is deleted and I have a filter on the line.

 

Evap was plugged shut just removed the jam idles around 45 psi now no less than 44 when I rev it up. Think I'm good to go, going to drive it around and read the plugs again.