Running lean when in boost?

[neverbeencaught]

Well I finally got the car running after dropping in the new 7m. We timed it after we gave her a good tune up, and she ran perfectly, until I hit boost. When I hit boost you can tell she wants to go, but basicly falls on her face. We thought it might be a boost leak, checked, it's not. So we hooked up my buddy's Air fuel meter, and I'm running so lean it's not even funny. I need to know what would cause this. All that is done for now is a 3 1/2 exhaust, so I know it's not a modification. Any idea's?

 

[thevork]

did you check for codes yet?

Could be a number of things. Amongst them are a faulty FPR (it's on your fuel rail), clogged fuel filter, failing fuel pump (they do fail after 20 years sometimes...)

Do you know anything about the status of your injectors?

 

[7mgte1988]

How much boost???
And what fuel Octane??

 

[neverbeencaught]

how do I check my codes? and i thought maybe my injectors where clogged so I'm going to take them out and check. Where are the fuel filters on these cars? and for some odd reason I didn't even think about the fuel pump. If it was going out though it wouldn't still run the way it does though would it? I mean I can drive it perfectly, until boost. I'm using the same FPR as I was before, and it was doing good.

Oh stock boost, 87 octane, only because a friend paid for the gas and refused paying more for it.

 

[Poodles]

no vacuum/boost to FPR...

Also, is it a wideband AFR gauge, or is it hooked up to the stock O2 sensor? Is it a GE to GTE swap? What parts where used from the old motor if it was?

 

[neverbeencaught]

it was a wide band. It was a gte gte swap, and I used the throtle body, fuel rail, knock sensors, and uper intake from the old engine.

 

[thevork]

it was a wide band. It was a gte gte swap, and I used the throtle body, fuel rail, knock sensors, and uper intake from the old engine.

As poodles said... Did you connect the vacuum line to the FPR?

Your fuel pressure increases along with your boost on a 1:1 scale.
So if you would be running 5 psi of boost your fuel pressure increases accordingly.

That's why you can idle/cruise just fine and have problems under boost.
Also, just to rule out the 8/12 volt relais to be the problem do the 12v mod. You can find info about that using the search function on this board.

This is hou you check for codes:
http://www.cygnusx1.net/Supra/TechTips/engine_error_codes.aspx

hth

 

[neverbeencaught]

yes the vacuum line is connected, I double checked. I also rechecked my vacuum lines, and I found out that I didn't have two things hooked up, but I dunno if that'd cause teh problem. http://www.supramania.com/forums/attachment.php?attachmentid=11439&d=1163204596

the first thing is circled, the second thing looks like a sensor or something, it's number 17650


also does anyone have a picture of the Cold Start Injector plug and wire? I'm not sure, but I think I may have forgotten to plug it up lol

 

[grimreaper]

egr and the green lines are the fuel pressure vsv. If thats not hooked up but your regulator is hooked up like stock, then no vac to regulator.

 

[7mgte1988]

how do I check my codes? and i thought maybe my injectors where clogged so I'm going to take them out and check. Where are the fuel filters on these cars? and for some odd reason I didn't even think about the fuel pump. If it was going out though it wouldn't still run the way it does though would it? I mean I can drive it perfectly, until boost. I'm using the same FPR as I was before, and it was doing good.

Oh stock boost, 87 octane, only because a friend paid for the gas and refused paying more for it.

If u jack the car up and look up over the rear axle and over the LSD you will see a black canister thing taking it out is another storie but if u change that u might as well look into the fuelpump cuz u might have to drop the tank.

 

[Poodles]

egr and the green lines are the fuel pressure vsv. If thats not hooked up but your regulator is hooked up like stock, then no vac to regulator.

 

[7MGTEsup]

^^^^^ I third that motion.

I hope for your sake you didn't boost to many times, I did it once because I had been doing some work and forgot to hook it back up. Got on it a few miles down the road and the afr was at 16:1 withing a few seconds so I backed out of it in a hurry pulled over and popped it back on. So if you have been doing it and holding it for along time terminal damage my have occured.

 

[neverbeencaught]

OK you're right, I gt my vacuum lines ass backwards some how, and still wound up with out leaks, so thats why I though they were right. only question is, where do these go? they're circled in blue.

http://i61.photobucket.com/albums/h45/Katzuki_Imara/vacdialp0.jpg

 

[grimreaper]

Never have seen a good pic of that vac. piece. Get a mirror and a flashlight and trace the tubing from one end to the other.