PFC, Pettit intake, PF sidemount hks bov and downpipe. I run pre-mix and occational octane booster from local solvent plant. I recently steam cleaned both rotors.42k original miles.

I have noticed in the last couple of runs that I have made in my the fd that my car has suddenly been making less power under boost. This is troubling to me because i had just fixed the first boost leak i have experienced with the car about a month ago (coupler from y-pipe to IC pipe). The car seems to boost fine (9-10lbs.) but im not getting the peppy surge from the stockers. The transition to the secondary is felt and seems theres no problem there. My knock levels run from 35-55, under vacuum it has gone higher. At first I just figured it had something to do with the air charge temp but I have reuled that possibilty out. I guess my next step would be to check for more vacuum leaks, compression test change plugs and wires. Is there anything else i should be checking? Voltage readouts? Please tell me someone else has the same problem?? Any help or guesses is appreciated.

Thank you,

Elliot

 

hello, so whats the problem then? maby your butt dyno is getting used to the power?
either way, check for other boost leaks. you fixed the weakest link, now perhaps the next weakest link is leaking.

 

I'll check my *** dyno to see it its working properly. The problem is a drop in the cars power not boost. When i let off the thoddle and get back on it the car is very slow to pick up again. Im pulling the plugs and wires along with fuel filter, compression test tomorrow. hopfully something pops up.
Thanks.

 

clogged main cat? boost leak?

 

Not sure what it is yet. I completed a compression test with both rotor hitting over 100psi. I changed the plugs and wire... a real PITA, ripping the thoddle body gasket in the process. I made sure the charge relief valve hose thats connected to both turbo outlets was tight. Next will be the fuel filter. Power from the turbos still isnt crisp. fells like it could be some sort of restriction in the exhaust. I'll check the cat to see if there's anything blocking flow. One thing i did notice is that when i walked by my rear driver tire i smelled gas and it wasnt coming from my gas cap area. weird.

The electrode from one of the leading plugs was burnt down to a nub.

 

Clogged cat will cause drop in power. I would pull the main cat out, and shake it. If you hear loose pieces rattling around, the cat may be clogged. You can likely shake most of the loose pieces out the cat, and clear it. It does take some time and patience to get them all out.

 

Reviving an old thread, I have the same issue you describe and is not my *** dyno as was suggested. I feel a power lose when boost comes on with an exhaust note change and lift throttle until off boost and the power comes back. I've check a lot of turbo controls and the only thing I've found is both the CRV and ABV only hold about 5psi with out vacuum applied to port A. Boost gauge reads boost on primary 5-7 psi and secondary 8-12 but it take a long time to get the secondary due to lack of power. Engine was rebuilt about 7k kms ago and has run strong ever since.
So my question is what pressure should the CRV and ABV hold on port C?

 

Took apart the ABV housing and found the charge side rubber seal is dried out and had some oil on it. Cleaned everything and used rubber renue on the seal, will test if it holds boost from passing before vacuum is applied. Have also seen a post where a stiffer spring is installed to improve low end response https://www.rx7club.com/3rd-generati...ck-bov-276067/ Just going to use a clamp to hold it together for testing.

 

So I'm about $10k into this issue, new SP turbos, fuel filter, plugs, wires, ABV, CRV, re-did all vacuum hoses again and bench tested all remaining solenoids (also tested by grounding ECU connector pins to hear click), new stock fuel injectors, solid IC pipes, full emissions delete with block of plates and Pineapple pulley kit...etc. Car has stock intake, exhaust is Feed downpipe, Bonez high flow cat, and RB cat back. All managed with a Power FC. Issue was intermittent and did not happen during a dyno tune until primary turbo failure (thus the new turbos) ended the session. After all parts installed issue is still happening under any acceleration to boost, light acceleration with out boost is fine but as soon as boost kicks in, power loss. Any ideas, going to pull cat back next and check if it's plugged.

 

Never had issues with one, but what would the symptoms be of a bad boost sensor?

 

So checked the boost sensor using mityvac and both boost and vacuum match PFC reading as well as mechanical gauge. Remove RB cat back and same issue (loud exhaust), removed Bonez high flow main cat (very loud exhaust) same issue, Feed down pipe is fully open, so I don't think it's an exhaust restriction.
I have unplugged the wastegate and turbo precontrol solenoids as well as tie wrapping the charge control actuator closed, this is to test the primary turbo boost only. The issue occurs as the car switches to boost, exhaust sound changes and power drops off, it recovers once you lift throttle.

 

Secondary charge valve or the solenoid that controls it opening too early or staying open. Or the exhaust flapper for the secondary turbo opening too early(assume solenoid fault).

If you find someone experienced with these they will likely fix it in an hour with a solenoid or two.

 

I have tie wrapped the charge control valve closed so there should be no secondary boost even at high rpm. I'm leaning towards LIM gasket or fuel issue (completely stock fuel system)

 

I have tie wrapped the charge control valve closed so there should be no secondary boost even at high rpm. I'm leaning towards LIM gasket or fuel issue (completely stock fuel system)