[kat] ran into some probs... just like everyone else :)

[Kreator]

Ok, finally started the car today, runs fine, no oil, coolant or fuel leaks (so far). There are 2 things that worry me though:

1. There is a leak at the manifold-turbo connection. i have a turbonetics metal gasket in place, but i don't think its doing its job... think some high temp copper silicon will fix it?

2. My a/f behaves funny... The gauge is autometer and i hooked it up to the white line on the harness itself (there were 3, white, blue and brown.. just checking if its right). The problem is the following: when i start up the car, the gauge reads stoich a little to the left from the center. As the car idles, the reading slowly moves into lean and stays there once it hits the lowest spot. The fuel pressure is a steady 38psi (yes, i know its low, but it doesn't explain why the ratio falls down from stoich to lean and doesnt just show lean all the time). So i'm clueless here. Other than i either hooked up the gauge wrong, or there is something wrong about the way i'm testing the system.

Any help is appreciated.

Thanx

[95Blue240sx]

for the second question...my friend had the same problem on his DSM. he replaced his o2 sensors and now it works fine. so you might want to check yours.

[240racer]

I wouldn't worry too much about the leak between the manifold and the turbo. I don't even have a gasket there. I don't think that a sealant will hold up to the temps. I would try to get a aluminized gasket like the manifold/head gaskets. I haven't looked for one since I don't care. I haven't really had any leaking there, so it hasn't become an issue yet.

[Kreator]

hmmm well, the car sounds like a freakin untuned v8.... as much as i appreciate the actual sound, the fact that it leaks so much doesn't make me happy.... Guess i'll have to look into that. On hte other hand, i used the copper silicon on the wastegate housing and it seems to hold so far...

Damn, i really wish i didn't have to spend the extra $50-$60

[sykikchimp]

have you tried sanding down the surfaces to make them flatter?

[Red]

Kreator - I have the Autometer A/F also. And I ran it to the white wire. Mine also hits the red alot while at idle but jumps back up to orange every little bit...

What does yours do when you give it a little gas? hold it at 2k?

And a question for ya... Does your gauge get all funky when you turn on any high power items like your lights... My a/f leds spred out when my lights are on.. and when I crank the music to 24 of 30.

What power did you tap into for your a/f? I tapped into my sig lighter.

[Kreator]

I tapped my fan power wire, which in turn taps the fuel pump.

i didn't try revving the car yet. just let it idle.... i'll do those things today, and will make a vid of whats going on.

[orion::S14]

Keep in mind that at idle and at WOT the A/F gauge will not do much - It will pick a place and sit there.

Yours sounds fine. If youy drive it, and under part throttle cruising, and light loads, if it goes rich-lean-rich-lean-rich, bouncing back and forth...then it's doing it's job. But the ECU doesn't change the mixture at idle - It has set values.

And try to run a dedicated power and ground to get a good reading - Autometer says that grounding is especially important...

Later - Brian

[Yoshi]

the autometer A/F gauges are only supposed to work at WOT, and everyone agrees that even then they are less than accurate and should NOT be used for tuning

[95Blue240sx]

Originally posted by Yoshi
the autometer A/F gauges are only supposed to work at WOT, and everyone agrees that even then they are less than accurate and should NOT be used for tuning

use a FJO for tuning

[Kreator]

uhhhh, noob question, but whats FJO?

also, i was wondering if anyone knows how much would it cost to tune it at the dyno with the wideband o2 sensor?

[mjbuch3]

If the exhaust ports are warped, it's going to be an expensive fix. If, however, your manifold isn't PERFECTLY flat, its a rather easy fix. If you get a file and slide it around on the "flat" manifold, you will soon see if it scrapes evenly. If it doesn't (meaning it isn't flat) you should get it resurfaced. You can also resurface it yourself by getting a perfectly flat surface (I've used a machine-cut marble slab in the past). Put sandpaper (600 or more) on the surface along with running water (a hose works great for this). Run the manifold back and forth along the sandpaper. Since the sandpaper is on the flat surface, your manifold will eventually flatten. Might take an hour or more, depends on what kind of shape your manifold is in. Personally, I would always use a new gasket. Also, you should be able to see carbon deposits where it is leaking (black ish spilling out where it leaks). Good luck, hope this helps.

[boosteds14]

Ok, YOur A/F Problem was a problem for me also.

This is what we did to fix it and make the car run better. use another o2 sensor just for the a/f gauge. the wire connected to the 02 sensor distorts the signal and gives a slightly wrong reading to the ecu. also get a ground that is the same as the 02 sensor that is dedicated for the a/f gauge. the power can come from anywhere, as long as it is battery power.

In other words, i have now 3 02 sensors: one front for ECU, another front for A/F Gauge, and one rear that with the JWT ECU does not use.

look at your plugs now, 80% chance they are WHITE. which is OK.

[Kreator]

Ok well, after some more tuning, i nailed the leak down to the manifold for sure. As for the a/f gauge, here is what happens at idle: vid (and during a little revving). When i took the car for a spin, the gauge would stay in red but would jump to the border of lean and stoich every second or so.... does that sound fine?

[Kreator]

Ok this is what i saw when i took the turbo off yesterday:



look closely on the longer sides.... see the 2 little slits? There are my leaks. When i was sourcing parts i didn't even think about it and didnt check when putting it on the car.... the turbo is t3, the manifold is t3 and the gasket is t3...

anyways. I just came back from the volvo dealership (the car my turbo is from) and the stock system doesn't use a gasket.... the manifold has a lift so the turbo just sits on top... so i'm stuck with 2 choices:

1. shave the mani so its all single level and get another t3 gasket (ummmm $60?)
2. use copper silicon (<$5 but will it hold?)
3. use gasket material and make a custom gasket out of it(~$15-$20 but who sells them?).

Ofcourse 2 and 3 i like more, even though 1 is the right way to do it.