Basically, with the stock pills, I get 10psi on the 1st turbo, 6 psi at transition, back to 10psi at 4500rpm and a sudden drop to 8psi at 4800rpm. Sometimes, when I'm in a higher gear, the boost will build back up to 9psi but most of the time it just stays at 8psi.

I've tee'd into all actuators (except Charge Control) and the wastegate/prespool solenoids. I did the FSM test on the CCA (key on) and the rod pulls into the actuator. Everything seems to be working ok but the prespool solenoid valve (on the actuator side) goes from 6psi to 4psi durring transition then shoots up to 13psi when the 2nd turbo is online. Is this drop to 4psi normal?

Today I tee'd into the nipple behind the CRV which is getting boost from the 2nd turbo. The boost pattern I got from this was:

0-3500rpm 0psi
3800-4500rpm 3-4psi (durring prespool)
4500- ~5000rpm 12+psi
5000+ drop to 10 psi.

Any ideas??

 

I dont' think it's normal that you see a drop to 4psi. I think it should be at 6psi (this pressure is actually an average pressure created by the duty control), then shoot straight to full pressure at 4500rpm, when the precontrol door gets slammed wide open.

Also, during the KOKO test, what did the turbo control actuator do? It should cycle also, but it frequently sticks.

Dave

 

The TCA does cycle in and out with the KOKO test. I tee'd into both sides and got -15inHg on the vaccum side (at 4500rpm) and 10psi on the pressure side (also at 4500rpm).

I'm guessing the problem has to be somewhere in the precontrol circuit since only 3psi from the secondary turbo durring prespool could only be caused by the precontrol door not being open enough or a defective CRV. The CRV checks out so...

I'm going to T into the line going to the precontrol solenoid (before going through the solenoid). If I dont see a drop there, I guess it's safe to say that the solenoid is defective.

 

Try unhooking the precontrol rod and see how much pretension is there. It shouldn't be more than 2mm worth of stretch to fit over the pin.

Dave

 

I checked the adjustment of the rod... it's right on.

Does anyone know if the wastegate solenoid valve can be interchanged with the prespool valve? I'd like to swap to the lines/connectors to troubleshoot.

 

Do you happen to still have your stock DP or a stock main-cat?

 

The lines and the connectors? I believe it should work no problem then.

Dave

 

DP, highflow cat and catback. I still have the stock airbox.

I'll try swapping connections to the wastegate/prespool solenoids... hopefully its just a faulty solenoid and not a defective actuator :S

 

your high rpm boost drop off might be caused by a clogged cat.

 

Just watch that boost level - going over 12psi is right near kaboom-land. Maybe it's worth having someone ride along so they can stare right at the gauge for you.

Dave

 

I dont see 12psi... my pattern at the intake manifold is 10-6-10-8.

I've tried flipping the wastegate/prespool solenoid valves but that didnt do anything, so that rules out a defective valve. I still havent checked the prespool actuator. I'm running out of ideas and patience .

 

Hmm, I should read more carefully. The 12+ I saw was on your CRV input line.

Dave

 

wanted to follow up with some more info. it's probably a clogged cat. to check it remove the bolts at the front of the cat to the downpipe and shine a light in there while you peak in. if the cat is not clogged, it will look like a fine mesh. if it's clogged, you will see parts of mesh that are melted and will look like a shower drain clogged with hair.

 

The clogged cat would explain the 10-8 drop at high rpm, but not the low transition. Can changing the cats change the transition too?

Dave