rich idle ka24de shortly after walbro and megan fpr install

[erollinc]

ok guys i searched for about an hour about this and i just really need a hand here.

i recently upgraded to a walbro and megan fpr after having some fuel pump issues, after setting the fuel pressure to 34 w/ vac and driving it and playing around with the pressure to see what changes it would make, ( 25psi to 50psi, just for curiousity) i discovered that 40-42 psi was by far the most optimal for hp, (butt dyno) so im having no idle issues at all and my plugs look great (a lil lean maybe)

so about a week later im driving north to waimea ( i live on big island hawaii) the elevation increases dramatically.... and the car starts to dip idle from 850 to basically nothig and recover And die and recover and so on..... so i check out the plugs and they a fouled with fuel.... but i i go drive the car hard and come back, they will show lean..... even with the fp at 28-30psi its doing this, at sealevel

i did also notice that im only getting a 5 psi difference in pressure from vac to no vac
i was thinking that maybe the megan fpr is junk and im getting too much pressure at idle and not enough at full throttle.

regardless i ran 40+ psi for a week with no idle issues.....so its kind of baffling.... all i know is i want 34 psi at idle and 44 at wot....

thanks for any help! the car is stock with the walbro and fpr

[erollinc]

bump.... im thinking maybe my maf was freaking out.... i unplugged it and plugged it back in and its running fine now... we will see if it keeps up

[compactfean]

This is why I don't buy cheap tuning parts. I run a tomei type L fuel pressure regulator with no problems... sard, tomei, nismo, and aramotive (or whatever that company is) have all been proven to be solid units. If you have your fp set at 34 and and gain 5psi your still 4 psi short which would cause a lean condition at. Wot. That's why your plugs are inconsistent. With that setup you have perfect idle and Lean wot. If you turn the fp up than you have a rich idle and good wot. Maybe its not that big of a deal though. I would check the connections. At the maf plug. See if there is any corrosion

[erollinc]

ima check the connections to the maf tomorrow... but on the way yo work today it started idleing reallllly bad and i pulled over, played with the maf connection and it idled and ran great

so you think its the cheap fpr causing the 5 psi difference?

[compactfean]

If you can wiggle the maf plug to get it to run better than there is more of an issue there than your fuel pressure. But yes ...5psi off on fuel pressure is huge.

[erollinc]

i know this is late but i thought id finish for searching reasons....

i bent the contacts in the maf connector just enough to keep it really snug and i havent had any issues since....

[sabretooth91]

Thanks for finishing up with what worked. I have also been told it is a good idea to use a speed density sensor instead of a maf. Can anyone explain the pros and cons of each. I'm new to turbos.

[airman86]

Thanks for finishing up with what worked. I have also been told it is a good idea to use a speed density sensor instead of a maf. Can anyone explain the pros and cons of each. I'm new to turbos.

A speed density sensor? Never heard of that. A MAP can be used but you'll probably need standalone/emanage for something like that. Most praises go towards the MAP if you can run it. Pretty sure the speed density sensor you speak of is synonymous with a MAP though.

[moso]

speed density is a way of defining the operation of map based cars. ie speed density = map sensor. the only way i know to get a map sensor on a 240sx is by changing to megasquirt, although im sure there are others.

[sabretooth91]

speed density is a way of defining the operation of map based cars. ie speed density = map sensor. the only way i know to get a map sensor on a 240sx is by changing to megasquirt, although im sure there are others.

What's megasquirt?

[airman86]

What's megasquirt?

http://lmgtfy.com/?q=what+is+megasquirt+240sx

[moso]

What's megasquirt?

http://lmgtfy.com/?q=what+is+megasquirt+240sx

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