How do I know when my fuel pump is at its limt?

[Kilo_SME]

Hi, I ask because I have a Atx tt and I get a real bad lean missfire at wot when my transmission goes to shift. On the logger my voltage drops to like 12. 5v at wot in the high rpm range. I'm not even sure what the limit is on the na fuel pump but I'm pretty sure that's my problem. I'm going to get a. tt one or something bigger anyway just to throw it out as a problem. Couldn't hurt to upgrade anyway. Also I want to ask, where does the Atx transmission shift because it looks like I'm hitting redline before it shifts.


Thanks

[Kilo_SME]

Maybe it's showing lean because it's misfiring because the plug gaps are to wide?

Steve

Could that be the problem? Because the gaps are to wide. The guy who owed the car before me had some Ford plugs in and I never the chance to change them.

[Kilo_SME]

If I get a video up you think you could listen to the missfire and help me out a lil.

[dpartinvr4]

didn't we decide it was your ECU and you need a wideband in your other thread?

[Kilo_SME]

The wideband is on its way. But a wideband wont fix why the car is missfiring, and its only during shifts which makes me think its a lack of fuel. I was really just trying to figure of out how to know if my fuel pump was maxed out, but he brought out some thing Im looking into. My plugs are the wrong gap I know of for sure and are dirt old. Why I didn't thing of this before idk but why nit just spend a couple of bucks on some plugs and go from there. I just replace all 3 coil packs but at the time didn't have the cash for the plugs so I never ended up getting them. As far as the ecu goes I've been pmingw 11 second fwd and he said he mad over 400hp on his NA ecu. He also started out as a atx tt and I was told that a wideband solid help me get a good tune goin untill I can get a good tt ecu.

[mb3000]

Plugs are dirt cheap if you get copper or non resistors.

[green-lantern]

The NA fuel pump is too small. Get a stock TT or walbro. You will have to mod your hanger to fit the other pump in but it isn't hard to do. As far as gap, I ran around 0.028-0.030 on my 10:1 TT.

[Kilo_SME]

Do I have to modify the stock tt one to? And I see a walbro in the parts for sale section. This might be a noob question but what is the strew on top off the TB. Not the tPS strew on the bottom,but on top. I turned it a lil and my car stared to idel alot better. Like it was getting move air or fuel.

[green-lantern]

Do I have to modify the stock tt one to?

Yep, I think you just have to remove the plastic piece on the bottom of the hanger and bend it out a little. Then just attach it to the hanger with one or two hose clamps. I'll see if I have a pic.

[green-lantern]

http://i61.photobucket.com/albums/h74/DCIV/1118071407.jpg

Well the pic sucks but you can see the bottom.......sort of.

[Kilo_SME]

Well my car never fails me lol. Took off the manifold to notice a big ass crack lol. I don't know if that has anything to do with my problem but that cant be good.

[IPD]

Do I have to modify the stock tt one to? And I see a walbro in the parts for sale section. This might be a noob question but what is the strew on top off the TB. Not the tPS strew on the bottom,but on top. I turned it a lil and my car stared to idel alot better. Like it was getting move air or fuel.

as paul said, the n/a pump isn't up to the task. a stock tt pump would be a MINIMUM upgrade; but i would suggest something like an aeromotive stealth pump; which should run quieter than the walbro while puting out significantly more throughput.

the screw on top of the TB should be the biss (idle set screw). my lack of one was causing me a boost leak--as well as causing the car to kill out all the damn time. :p i set mine by putting my car on a gentle incline, shifting from neutral to drive, and tapping the gas. this causes a momentary rev, and then the idle drops. i turned the screw so the idle will be just slightly above where it could kill out while doing this. (this method causes a sharper idle drop than a "regular stop" on a flat surface at a stoplight or some such). long story short, since i set my idle in this fashion, i won't have to worry about it killing out under any other driving circumstances due to low idle.

again, check the plugs, upgrade your pump, and try again. i've got no blowout on my atx tt.

[green-lantern]

Well my car never fails me lol. Took off the manifold to notice a big ass crack lol. I don't know if that has anything to do with my problem but that cant be good.

Which manifold? Can you post a pic? I'd say it's a problem.

[IPD]

i wish terminology was more specific. here's what i propose:

intake = upper or lower plenum.
exhaust = manifold (if stock) or headers (if aftermarket)

"manifold" says NOTHING in itself.

[Kilo_SME]

Lol sorry I was thinking off intake manifold. Its the upper intake plenum. I will get a pic up here as soon as I take it back off again wasn't planning on something like that and this is also my DD right now. I'm kind scared to drive it now but bird just a couple miles back and fourth and I will just try to stay out of boost. I guess I have s couple of things left for the car and just when I thought I could spend anymore money on this car.

[green-lantern]

Modding a car=expensive!

Yeah I'm pretty sure you're getting an intake leak with a crack so replace it ASAP! Are you using TT or NA plenum?

[Ninja Performance]

To your original question. To test if a fuel setup is out of fuel due to the pump, you need to watch your fuel pressure. Line/head pressure should rise 1psi per 1psi of boost pressure. When your line/head pressure stops increasing with boost or even worse starts to drop as pressure levels off and RPMs rise, your pump has run out of the ability to deliver the volume of fuel needed to keep up with demand. When logging data, your fuel pressure line should mimic the boost curve. If it drops while boost pressure stays constant or is rising, the pump is done.

-Chris

[VR-4 0wnz j00]

Should be the ISS or something. Idle air screw?