So I used to run lean all around after a few months from when my build started so I put in Walbro 255 about 2-3 months ago. My idle afr's were right on 14.7 for the first time and I was holding the stock fuel pressure at WOT much better which gave me richer afrs. I was happy. The other day I got some new wheels and just before putting them on I did a little burnout to get celebrate the removal of steelies. Now I'm not saying this was the cause, but I noticed the idle afr's immediately after went to the 16/17 range. It would go to 15 once in a while but would keep going back to 16's. Under load, things seem "okay." The numbers are close to the same for the most part. I noticed though that the fuel pump got a little bit louder when I would do two clicks on the ignition to prime it. Also, I noticed today after driving, 2 clicks would pressurize, and my fans would come on (hopefully, those came on just b/c my car was still hot). Anyways, anyone think the louder fuel pump may be the reason my idle afr's went lean?

 

what kind of injectors? ecu setup?

 

dsm 450cc's and tuned on Crome

 

brunch time bump

 

the walbro is way louder than the stock fuel pump. so there's your answer to that..

and how long have you been using your wideband? have u run any race gas through it? or just pump? was it calibrated before using?..

 

Lol I was waiting for someone to say "walbro's are loud." Yes, I know they're loud, but it has gotten louder. As for my UEGO, from what I understand, they are not able to be re-calibrated. I installed a new sensor as of September b/c my older one got dinged by a good ole rock and it failed.

 

I know the little plastic stud/tab that uses the retaining clip to hold the pump's filter on broke before the install. I asked about it on here and a lot of people said the filter would still hold on there fine. They had the same issues and nothing happened to them. If somehow my filter fell off, do you think that could be my issue? It's still fine during normal driving which is why I assumed that wasn't the reason.

 

very early morning bump

 

clogged up fuel filter?

is the pump only louder on the second prime?

 

fuel filter is nearly brand new.

 

so anyone else thinking if the sock filter fell off the pump, it just wouldn't run?

 

I'm pretty sure the pump would still work if the sock fell off...unless the sock fell off and something from inside the tank (rust) plugged up the pump (doubt it)

how is your fuel pressure? regulator on its way out?