Sorry, the site froze up and the original text did not get posted....

O.K. I have done a search, read the Autosport Race tech site and Robinette site. I know there are alot of boost threads and questions. I need the experts to help me with this one!

I just completed the silicone hose job. I 12v tested and replaced every questionable solenoid and check valve. The CCV and it passes the KOKO test, i.e. it pulls in when you switch the ignition on. The Wastegate control and turbo precontrol solenoids work perfectly.

I have replaced the plugs and wires. Injectors were cleaned and balanced by RC engineering. The FPD was replaced. See my sig for mods.

I looked under the car, the rods for the turbo control and turbo pre-control actuators are attached. I am not getting any engine codes.

Here is the question: Now that the car is back together, at WOT the boost starts at 0 psi and slowly climbs up to 12 psi in about 5 seconds. If I rev the engine the go WOT it boosts quicker but still not as fast as when I was stock. Makes me think I have vac leak. The pressure and vacuum chamber both hold without any leaking according to the Mityvac pump. What am I missing?

Anyone got any ideas of the next things to test?

 

At what rpm and gear do you go WOT?

 

Almost any gear. The usual WOT test is in 3rd gear at about the 2-3K rpm range.

 

anyone? - bump

 

check intercooler piping/couplers?

 

Yeah, I replaced them all with new silcone couplers with the PFS IC.

 

I found out that my cats were clogged and replaced the pre cat with a DP and the main cat with a MP.

 

if your in 3rd gear going wot at 2k rpm. its gonna be slow.

 

Did you check the vaccuum box besides the alternator and the check valve? All check valves must be in good condition for the secondary to build boost quickly.

Also, what about the vaccum like to the actuator on the Y-pipe?

I'm also assuming that you hot tested the TC solenoid located under the UIM but above the fuel thermosensor?

 

Thanks guys for the replies!

Batman - I have a DP and put a Gotham High flow main cat on last year. I should be free of any clogs. (see my sig below)

Pomanferrari - I did check the vaccuum box and pressure tank. Both are free of leaks. All check valves were replaced. Vaccum at the actuator is perfect. I did not HOT test the TC solenoid but this occurs whether it is cold or hot.

Keep the ideas coming. This has me stumped

 

what is your sequence of boost? do you get double digits below 4500 rpm? does the boost dip a couple of pounds around 4500? does it recover to over double digits after 4500 and the tail off around 6=6500? if your boost resembles above then it is probably not a turbo/control issue. more like a clogged cat/exhaust.

howard coleman

howard coleman

 

How many miles on the turbos?

When I took my turbo off to replace the engine, the wall divding the wastegate from the exhaust inlet was basically leaking boost past the wall causing slow boost rise.

th

 

I had the same problem before I did the silicone hose job and the problem was that the vacuum lines going to the pressure tank were so hard that the tank wouldn't stay pressurized.
Having the check valve reversed on the pressure tank would probably cause that. If you give it boost and then stop and pull a hose off the pressure tank can you hear it depressurize?

 

mgoddard1 , good thinkin.... props....

 

double check that you reconnected the electrical plugs to the wg and prespool solenoids (the ones facing you in front of the UIM) properly. switch the plugs around to verify.

you should be getting boost very quckly (or at least i do).

also check that none of the vac hoses under the UIM are squished. that happens often.

 

Howard - My boost dips at 4500 to about 6 lbs and stays there. Classic secondary boost problems. That is why I did the hose job to begin with. I guess I did not find the problem. I think maybe my turbo actuator is bad.

Pomanferrari - Wow! This is some picture! I have 68K on the turbos. I am the third owner. As far as I know they are original. I have not taken apart my turbos to know if my manifold is cracked like your photo. That could be the problem. I will not know unless I take it apart. I don't think i have the ability to that. The hose job was a streatch for me do as it was.

mgoddard1 - I think you were RIGHT ON! I did your pressure chamber check and did not hear air coming out. I found a check valve that was reversed! Now boost comes on much quicker. THANKS DUDE!