very rich at idle but super lean at WOT

[silverex]

I just got a brand new plx m-300 wideband and installed it yesterday. At idle my a/f was in the 11s, so i lean it out with the afc 35% and now it hovers around 14.5-15 and idles much better. After that i took it for a rip around the block and noticed that my a/f was in the high 12s and 13s I added a bunch of fuel and it was still in the 12s and i called it a day. My mods are
built motor 8:5:1
web cams
20g @ 18psi
supra fp without rewire
pte 680s
afc/vpc w/ 550 chip
keydiver chip for everything,
The super weird thing about it was i never saw any knock on my boost gauge and i def did some pulls with a logger when i first got the keydiver chip and i got NO knock. I'am thinkng it might be a fuel problem and wanted to know how i could check a couple of things.
My fuel pump isnt rewired so how can a see if thats getting enough power?
I have a aftermarket fpr...can they go bad or do anything like i'am describing?
Any help would be great
Paul

 

[TwoLiterLaser]

Have knowledgeable shop give you a good tune and be done with it.

 

[silverex]

I belive its a part problem and not tune related. With my keydiver chip i shouldnt have to make such big adjustments with the afc. Taking it to a shop to get tuned only to relized that my fuel pump is dieing or something else would be a waste $ which i dont have.

 

[andymoraitis]

Let's start with the simple stuff and work forward. What I'd like to know is what your base fuel pressure is with the vacuum line off? Also what kind of FPR is it?

You can check fuel pump voltage with a meter. Optimally, you want to make sure you're getting at least 12.5 volts and a re-wire should push you around 14 volts or so. Here's a link to a fuel pump flow sheet for stock and re-wired pumps.

http://www.roadraceengineering.com/fuelpumpflowrates.htm

Your pump should be more than good enough for your setup even without a re-wire. In that light, I'd check the voltage and possibly replace the pump if it's getting old to eliminate that as a potential problem. Look for any leaks or tears in the o-ring setup or clogs in the filter sock if the Supra pump has one.

I'd also consider a potential issue with the fuel filter as a possibility. From what you describe, this doesn't sound like a tuning issue, but more like a bit of fuel starvation up top.

Let us know,

Andy

 

[silverex]

fp is 37.5 w/ line off.
aeromotive afpr
i'll check the pumps voltage and see if the o-ring is riped or anything.
I ordered a new fuel filter and that should be here anyday. I also agree and think its not tune related but wouldnt i see knock with low 13 afr at wot with 18psi?

 

[andymoraitis]

How much knock you'd have at that boost and AFR is more dependent on how much timing you're running that the actual AFR (to a point). It's pretty obvious that combustion temps may not have been high enough to trigger knock, but with a few more psi you would likely have seen some.

While I don't use a wideband, I know some need to be calibrated. have you calibrated yours recently? Also what brand of wideband is it.

P.S. Try increasing fuel pressure to 40 and see if A/F is affected. If not, it's most likely the pump dying or the filter starving the rail.

 

[silverex]

i have a brand new plx m-300 wideband and i'am pretty sure this one never needs to be calibrated.

If the fp has good voltage i'll bump the fp up and give that a try tomorrow. When i check the fp will i see a ground and a red wire right there to test on the top of the pump?

 

[andymoraitis]

Search is definitely your friend:

http://www.dsmtuners.com/forums/showthread.php?t=33933&highlight=check+pump+voltage

 

[silverex]

I'am thinking it could be my afpr is there anyway to check it?

P.S. Try increasing fuel pressure to 40 and see if A/F is affected. If not, it's most likely the pump dying or the filter starving the rail.

I bumped it upto 39 and it ran richer and better on tip in. I doubt its the pump or the filter but i'am still going to replace the filter.

Search is definitely your friend:

http://www.dsmtuners.com/forums/showthread.php?t=33933&highlight=check+pump+voltage

Yea, that didnt help at all and a search didnt bring anything i'am looking for. If you can tell me where to put the 2 leads from my volt meter for my galant, that would be great.

 

[andymoraitis]

If you want help with a GVR4, you can PM Quasimondo or GVR4592. I'm sure both of them will be able to guide you in the right direction.