car running lean under boost

[Clark6]

I may be wrong but maaayyybbeee you need just a little wee bit more injector. like 60s or 65s?? pending the pump checks out fine. But what do I know?

 

[big reazon]

My car had the same symptoms when my ignition module was going out changed it out along with new plugs problem went away.

 

[Ttype6]

at 6pm I went out and flipped the key on to pressurize the fuel system. Got back about 10 minutes ago and had just over 15 psi still reading on the guage.

This means nothing. What is your fuel pressure at 17 lbs of boost? What is your fuel pressure at 21 lbs of boost?

 

[bison]

I may be wrong but maaayyybbeee you need just a little wee bit more injector. like 60s or 65s?? pending the pump checks out fine. But what do I know?

Not unless he's making about 675hp and no alky.

 

[usetaboost]

This means nothing. What is your fuel pressure at 17 lbs of boost? What is your fuel pressure at 21 lbs of boost?

I posted that information so everyone knew it held pressure and wasn't leaking past an injector or leaking internally inside the tank. Fuel pressure is around 65 at 17

 

[usetaboost]

I don't know exact numbers. Not trying to get in a head on collision on the highway, the fuel pressure is rising and keeping pressure

 

[jdpolzin]

Jessie, do you run a volt booster?

 

[usetaboost]

Not unless he's making about 675hp and no alky.

I wish my car made that much

 

[usetaboost]

Jessie, do you run a volt booster?

No volt booster. Heard they fuck up the progressive controller ramps or somethin like that

 

[usetaboost]

Trying to find something that shows the layout of the harness so I can verify the harness and see if it's getting the same voltage as what the scanmaster says

 

[jdpolzin]

Well, I'm not sure on the alky system if they do that or not. But, I have heard of that issue so I figured I'd ask. I have seen a few failures on the bulk head connector on the fuel hanger and loose connections. I know its a pain the butt, but that may be a place too check. Chuck's car just burned one up a few weeks ago. Just an idea.

 

[bison]

Trying to find something that shows the layout of the harness so I can verify the harness and see if it's getting the same voltage as what the scanmaster says

Forget the factory harness. Its crap. Run your own wires. The vendors sell a harness/relay made for this. The voltage the scanmaster reads means little also.

 

[Ttype6]

I don't know exact numbers.

You have to have 63 steady pounds of fuel pressure at 21 lbs of boost if you have 42 at idle (line off). If you do,you don't have a fuel delivery problem and you can look elsewhere. If you don't, you have to fix your fuel delivery problem. This number is the only thing that matters and must be ascertained to know what your next step should be. Have someone watch your gauge to see if the rise matches your boost. I would turn the alky off and the boost down to 17 first,then proceed from there.

 

[usetaboost]

I got the fuel psi under boost. No dips or fluctuation that I saw

 

[Ttype6]

I got the fuel psi under boost. No dips or fluctuation that I saw

What number did you see at what boost?

 

[usetaboost]

65 at 17, guage held steady. Was not wot, can't get the boost under 20psi but I don't think this matters much since I know there is a true lean condition since it back fired and 02 read .580 when this happened. I know this isn't a true wot 3rd gear pull but the car does the same thing, leans out and starts getting kr.

The other day when I took it out to see what the scan numbers were I maxed wot fuel and 02s went from .680-.720 Don't know if this helps but figured I'd throw it out there

 

[usetaboost]

Forget the factory harness. Its crap. Run your own wires. The vendors sell a harness/relay made for this. The voltage the scanmaster reads means little also.

I got a hotwire kit on it, you talking about the wiring coming off the sender?

 

[usetaboost]

Looking at the TT order sheet he has my injectors listed as 55lb msd's. DOn't know if he forgot to change it when I emailed him back or if it even makes a difference but they are actually 57lb siemens low imp injectors 3102's

 

[Ttype6]

65 at 17, guage held steady.

At 17 lbs of boost you should see 59 lbs of fuel pressure. What is your base fuel pressure (line off)?

The other day when I took it out to see what the scan numbers were I maxed wot fuel and 02s went from .680-.720 Don't know if this helps but figured I'd throw it out there

It shows that the motor gets more fuel when the injectors are turned on for a longer period of time. This is a good thing.

 

[usetaboost]

45 line off, operating temp