Hi,

I was having intermittent boost problems (sometimes going as low as 0 psi) on the secondary turbo. Sometimes full boost is achieved. I have removed the intake manifold, tested the CRV and the BOV and found no problems, and would like to know what to look for under the intake manifold. None of the vacuum hoses appear to be disconnected. What else is there to look for?

Thanks,

Andrew Wojteczko

 

Hey,

anyone? please help as I need this car back and running for a race this weekend.
thanks again
andrew

 

Also look for any broken or cracked hoses. You might as well replace your rubber hoses with silcone ones. Did you check your y-pipe coupler and the intercooler couplers/hoses?

 

Also, verify the check valves are still functioning correctly.

 

I will take a close look at the y pipe and intercooler couplers/hoses, thanks for the tip.

 

yup, since you have it open, try and get all the check valves replaced. if possible, test all the solenoids, and replace the vacuum hoses with silicone ones. (be careful though, you need to be very cautious when testing the solenoids and changing the vacuum hoses- solenoids retail for around 50 dollars each). bad solenoid could be the cause of low secondary turbo boost (find out if the secondary turbo depends on any of the solenoids for functionality).

might i suggest replace/upgrade the spark wires (if you havent done so recently).

 

i just replaced the plugs and wires(original NGK) last night, much easier while everything is off.
if a solenoid is malfunctioning will it work occasionally or totally fail, is it possible for them to produce full boost some times and not others?
Also, how should I check the check valves for leaks? should i just put a vacuum pump on and see if any air will blow through in the wrong direction?

Thanks again,

Andrew Wojteczko

 

Most of the check valves you can just test by blowing through them, you shouldn't need a vacuum unless you want to make sure they open at the right pressure.

 

ok, i checked all 5 check valves, they are all working correctly, the pressure tank holds vacuum, and the y pipe coupler appears to be fine. I'm running out of ideas here, I am going to start checking solenoids but asides from that, what else is there? I'm running out of time, need to be at the track friday night.

Thanks again for the help,

Andrew Wojteczko

 

What exactly is your problem?

You "sometimes" loose boost? Is it on the primary or secondary turbo?

Does it happen every time after the car heats up?

What mods are you currently running?

 

ok, i'll start with mods
stock box ducted between rad and frame rail, blocked in front with K and N panel
Mazda comp downpipe
greddy Power Extreme Cat Back
Home Depot Boost controller (2 needle vaves on prespool and wastegate, used to work fine)
koyo rad
original vacuum lines,
93 R1 with 87000 kms.

ok, now the problem, I always have boost on my first turbo, however after 4500 rpm, boost will sometimes fall off to 4 or even 0, and sometimes will pull hard at 11 like it used too. Operating temperature has no effect, it has this symptom all the time. It also seems to happen more often in first and second gear, third seems to pull propperly more often than first or second, but is not consistent.

Thanks Again, if you need any more info, let me know.

Andrew

 

oh, and a pettit unlimited ECU, I think that is all of the major mods

 

How old is the main cat? (I'm assuming you are using the stock main cat as you didn't list a high-flo cat or midpipe).

 

yeah it's a stock main cat, however i can't see how that would account for perfect boost on the first turbo, and random boost patterns on the second???

 

Usually most people will point the finger at the cat when there are inconsistant boost problems. If it were a vacuum hose, valve or something else, your boost would either work fine or not at all.

 

See if you have any hoses (small or large) that are collapsing under vacuum. Those can cause intermittent boost problems that can be really hard to find.

Wade

 

I will take a look at the cat, maybe remove it and take the car for a spin and see if anything improves, i'll watch for boost creep. thanks for the help

andrew

 

you may need to replace your gasket now that you've taken the manifold off..

 

thanks, i'm picking one up tonight, i'd hate to have to do this all over again because the gasket didn't seal propperly.