Intake Valves!

[BR1JZL]

Hi all,

Reaching out to the brain trust here, about a month ago I cleaned my intake valves, and today I had to take of the intake to install a JBR TIG, and thought I would check the condition of the valves whilst I'm there. Intake valves for cylinder 2 and 3 are clean (3 is cleaner than 2) but the valves on cylinder 1 and 4 are caked up again. I have tried to take pictures, but to be honest they aren't great. Is this normal or what is the cause for some to be worse than others?

P.S I still have to install an OCC, but have changed the PCV valve last time and blocked off the EGR as well.

[MSMS3]

Is your signature mod list correct? If you are running that 3” catless downpipe (even with the required hpfp upgrade) on stock tune you are likely to soon blow your engine. You are likely getting really high nasty boost spikes and unsafe AFRs. You need a tune compatible with the increased flow on the exhaust side.

You should be a lot more concerned about that than what direct injection does to the back of your intake valves.

Do you have a way to monitor and log engine operation?

[180mph]

Originally Posted by MSMS3 Is your signature mod list correct? If you are running that 3” catless downpipe (even with the required hpfp upgrade) on stock tune you are likely to soon blow your engine. You are likely getting really high nasty boost spikes and unsafe AFRs. You need a tune compatible with the increased flow on the exhaust side. You should be a lot more concerned about that than what direct injection does to the back of your intake valves. Do you have a way to monitor and log engine operation?

I concur with this man. When I was in the early stages of modding my MSP3 my Ebay DP install definitely caused major overboosting. I did one pull (to 4500 RPM in 2nd gear) on a Cobb OTS stage 2 map and immediately got an overboost CEL. Scary moment for me and I have been much more cautious ever since. Get an AP (or tuning software of your choice) and flash an OTS map at the minimum.

As far as the valves... considering that you do have the DP some say that an Oil Catch Can could help with carbon buildup. From chemistry class I learned that the based way to clean carbon is with massive heat. Since Cyl 2 + 3 run the hottest could explain why you see less buildup on those two cylinders. Also if emissions allow it in your state delete that nasty ass EGR too. That shit is dirtier than a coal plant in West Virginia.

[BR1JZL]

Thanks for the response, sig is correct, I have my wedding coming up, so all funds are on hold, but I have been monitoring via Torque and baby the car, until I can afford a Cobb.

AFR goes as low as 13 ish, but generally staying around 14.7.

[Vansquish]

Originally Posted by BR1JZL Thanks for the response, sig is correct, I have my wedding coming up, so all funds are on hold, but I have been monitoring via Torque and baby the car, until I can afford a Cobb. AFR goes as low as 13 ish, but generally staying around 14.7.

Yeah, but under even fairly mild throttle, it should be around 10.5-11.0 on the stock tune. You're really running dangerously uncontrolled right now.

[MSMS3]

Originally Posted by BR1JZL Thanks for the response, sig is correct, I have my wedding coming up, so all funds are on hold, but I have been monitoring via Torque and baby the car, until I can afford a Cobb. AFR goes as low as 13 ish, but generally staying around 14.7.

Way too lean for a direct injection turbo engine under boost. Be careful to avoid even mild boost until it is tuned.

[180mph]

For comparison the ots cobb map will put you around 11.6 @ wot. 13 is good for partial throttle and fuel economy but a big no-no for actual power