Got Boost, No Boost, Got Boost, No Boost...WTF?
 

I have a problem with my boost. Sometimes I have boost, sometimes I don't. This morning when I went to work, the first 20 minutes of driving yielded no boost or very little boost, maybe 1 or 2 PSI. And then, like a switch, all of a sudden I have full boost again, up to almost 10 PSI. The car seems very sluggish when I don't have boost, like I am towing something. It will switch off and on throughout my drive. It doesn't switch while I'm driving, it "magically switches" while at a light or a stop sign. Anyone ever have this problem before? There is no smoke, or oil loss in any way. Coolant is fine, the overflow fills when hot and draws back in when it cools. I can get my hands on another turbo, if you guys think I should swap it out to see if it changes at all. This problem along with my idle being all screwed up is giving me a headache. ARGH!!! :mad:

Check the connections at the leading coil pack. I’m not guaranteeing this is the cause, but a loose connection at the leading coil will produce exactly those symptoms. When the leading plugs aren’t firing, it’ll be smooth but with about half the power there should be.

BRB

OK, I checked the connections at the leading coil and the L2 wire was not as seated as the L1, but I wouldn't think it was out far enough to not make a good connection. It was maybe an 1/8th of an inch. I can check it out tomorrow on my way to work. I can't sleep and I thought I ought to ask someone on the forum about it. Thanks, NZ....any other ideas?

Sorry, should've made that clearer. I meant check the little two wire connector that fires the coil. The leading coil is one double ended coil; either both plugs fire at once. If that little plug's loose it'll drop both leading plugs and run smoothly (but very slowly) on the trailing plugs. If just one of the high tension leads is loose, it'll run roughly on one leading plug.

double throttle throttle plates.. check to make sure they are opening.. or wire them open or remove them complete (throttle body mod) .. They are controlled by a checkvalve and diaphram.. the plate is there to limit boost your motor recieves while the motor is still cold.. if the checkvalve or diaphram is faulty, the plates don't work as they should and you will get intermittent power problems..

I've been contemplating doing this for a while. When the J-Spec was installed, most or all unnecessary items were left in the garage, no accell warm-up, twin scroll, rats nest, all solenoids except the one needed for fuel system. So, I don't think the TB mod would affect my idle any more than anything else I have done. Can you give me acrash course on removing the plates? Is it just removing the screws and plates and JB weld the holes from the linkage?

That plug seems to be ok. I can try to pull it apart and clean it up a bit. On my maiden voyage after the J-Spec install, I blew the front oil cooler line at the top of second gear at 7K RPM's. Needless to say, the engine bay is a bit dirty. I've simple greened it a couple of times, but it's still dirty. I lost 5 quarts of oil in a matter of seconds. I didn't have the hood on at the time, and the windshield got completely covered with oil and then the oil buzzer went off. I shut it down immediately and coasted into a gas station to see what the hell I did. Not fun. Luckily, I was at my mechanic's shop and he has quite a few parts lying around.

On my lunch break, I went out to change my boost gauge, since mine is not calibrated and summit sent me a new one. Get everything all done and check the gauge with the key on and the needle stays in the little box like it's supposed to. So I start the car and decide to take a spin around the block. I have no idea if it's just a coincidence, but my boost was working again. I don't understand what's going on. I didn't change the boost line or mess with anything except swap the gauge unit itself. Do you think my boost gauge could have been screwing things up? I wouldn't think so, but right now, I'm thinking this car is the devil.

rx7's are the debil!

It was just a coincidence. Dammit.

My TII had this problem when I bought it; it was a cracked precat that would shift position to become a major exhaust restriction.

I see you have a downpipe, but is it possible you have a broken up main cat? Did you remove airpump and keep the cat?

I still have the main cat in place, but it is gutted.

I'm tearing into it tonight and starting with the injectors, hoping they are not seated properly.

Check your w/g actuator. I guess the diaphram could be dried out. You know that thing sits near 1000 degrees all day. Try applying vaccum or pressure to the w/g and check the entire operation of the things down there.

Do you still have the twin scroll crap on there? Rip that stuff off if you are ever in the area. Also check that actuator to see it thats working right. There a long, hard vac line thats right around there. make sure thats good.

Thanks, Saabguy. I'll check the actuator tonight. The twin scroll stuff is gone.

Saabguy, you are the winner. I went to my mechanics shop tonight and we started searching for problems. We got the pump out and did the test per FSM on the w/g and the linkage didn't move. So we head upstairs to his array of parts on the shelf and find his pile of wastegates and put the pump on it....the linkage started to move. So, back downstairs we go to see why my linkage didn't move when the pressure was applied. We got to looking at the w/g and the damn bracket that the w/g was bolted to was bent just enough so the linkage rod would go out and stay out, thus giving me a huge boost leak into the exhaust. So he bends the bracket back and check the linkage to see if it's straight. I jump in and start it and off I go for a test run. Boost is back and then some. First gear never boosted above 4 PSI and now it goes beyond 5. Third gear gives almost 10 PSI. I'm glad my boost is fixed, but my car still idles like crap. I hopefully figure out that one on Saturday. Happy for now :D