Idle problems, also think im burning oil. Need a little guidance.

[Womb Raider]

So I got my MSP a couple months ago, been doing a lot of work on it and im pretty content with the car itself. After a big project; gt35 turbo, '3 pipings, obx exhaust manifold, coil kit,mishimoto radiator, precision wastegtate and a couple other maintenance work like water pump, motor mounts, timing belt, I noticed that when i would come up to a traffic light my rmps would drop to like 400- 500 then pick back up to like 900-1000 sometimes the car would just die on me. I thinking its my iac, just ordered a new one a couple days ago. While i was checking fluids in the car i noticed my oil was low, I changed it a couple weeks back. Could that have anything to do with it? I'm also running a little lean since i only have one o2 sensor on my exhaust side at the moment.

Here's some of my build pic's. Lost most of them

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[hornsfan10609]

Is that correct a GT35 turbo? Did you build the motor? Only the bottom pics work, try a website like photobucket to more easily post pictures. The idle issue sounds like a vacuum leak, dirty maf, clogged IAC or MAF sensor or a combination of those things. O2 sensor should not cause you to run lean, only the ECU will unless you have aftermarket EMS or a piggyback. Considering how rich these cars run, even with a turbo that large the car should not be running lean.


Burning or leaking oil is normal and is not affecting the idle.

 

[Ractive]

Do you have an aftermarket blow off valve venting to the atmosphere on the stock ECU? This will cause the RPM to drop when coming to a stop and back up. Reason is there is no circulation going back to the turbo(stock bypass valve). I believe the engine runs a bit rich when coming to a stop with the stock ecu. If you light tap the gas pedal right before coming to a stop it would actually help. Looks like you have a big project but these engine and trans can't handle much hp. Good luck with the build.

 

[Womb Raider]

Thank you. Here's some more pictures










Yes it is a GT35.
No all my internals are stock.
I just changed my iac and found a lot of carbon build up and a crack on my old one. I can feel it running better but it still drops rpms real low and picks it back up once i throw it into nuetral when coming to a stop

 

[Womb Raider]

Thank you ractive. Yes i do have an aftermarket greddy bov. Is there anything i can do to prevent that from happening, besides having to remove the bov?

 

[Womb Raider]

Bump

 

[hornsfan10609]

Good luck bud, these motors can only handle about 10-12psi on the stock T25. A T35 running anywhere near 8-10psi is going to annihilate the connecting rods and give you a couple nice holes in the block. Before you blow it up and blame the platform and go around bad mouthing proteges the next few years you should rebuild the motor with forged internals. The trans is another story

 

[Womb Raider]

hahaha great.

 

[njintau_fsd]

Looks good man! I've got to ask, do you have enough space to fit the radiator now? The clearance between the turbo and the radiator is so tight, I'd be legitimately surprised if you were able to fit the radiator and keep the stock fans.

Are you still running the stock ECU? That might be your first problem and yeah the lack of an O2 sensor may actually be a reason for your car leaning out. The ECU uses the upstream O2 sensor to meter the amount of fuel and without it, the ECU basically goes into open loop, blindly dumping fuel. So now, you'll lean out when you step on the gas or idling and run super rich when you slow down (this happened to me when my O2 sensor gave up the ghost.) I'd start with adding an upstream O2 sensor then look for vac leaks if that doesn't fix the issue. Eventually though, I'd go for a piggyback or aftermarket ECU, especially if you want to run high boost.

Btw, you're running a GT35 using the stock engine?! Oooh that's not a good idea mainly cuz the FS was never meant for boost and, like hornsfan said, you'd more than likely throw a rod if you run 8 psi or higher. I highly recommend you invest in forged rods and pistons and stick to low boost until you do, otherwise you will need a new engine.

Edit: Looks like I double posted here (crappy internet lol), any mods want to remove the previous post, I'd appreciate it...

 

[hornsfan10609]

You can delete your own posts, hit 'edit post' and click 'delete'.

 

[Womb Raider]

Appreciate it man! Yup, it all fits. Yeah im running stock boost at the moment. Guess i should start looking into getting a smaller turbo haha. Thanks for the advice Nij

 

[hornsfan10609]

Smaller turbo or forged internals, that thing won't hit full boost until over 3krpm with a little 2.0L trying to push it.

 

[OThree.5]

Appreciate it man! Yup, it all fits. Yeah im running stock boost at the moment. Guess i should start looking into getting a smaller turbo haha. Thanks for the advice Nij

What part of NC are you in? The MSP in NC seems rare.. so far I only know of myself and 1 other

 

[Womb Raider]

Baha i get turbo lag like a mf. Been looking at a garret t25 dual ball bearing with internal wastegate. Prolly just end up selling my t35 and percision wastegate

 

[Womb Raider]

What part of NC are you in? The MSP in NC seems rare.. so far I only know of myself and 1 other

Jacksonville man

 

[Womb Raider]

Bump