Lack of power past 4500rpm - help please
 

Hial to the Rx7 Massive,

had my 93' 3rd gen for about 2 months now - absolutely love it, or i did when it had power!!!

the problem im having is when i go past 4500rpm the power drops to nothing, i can still hear the wistle (sounds noiser than usual) of the turbo when i have my foot down but when i take my foot off i hear a 2 second 'wherring' noise and all the boost is blown off (it doesnt sound like the normal hisss its more like a wherring noise)

the wierd thing is it works ok when engine is stone cold for about 15 mins and then when warm you can feel the drop in power when you put your foot down all the way. if you start up from warm the problem starts straight away. and if i put my foot down just enough for the turbo to start working there is power but the further down my foot goes the less power there is????

the car is pretty much stock apart from a pair of apexi air filters and an apexi rev/speed meter which is disconnected.

i have replaced the o2 sensor and am using a higher octane fuel which has helped a little but theres still no power above 4500rpm



as this problem only happens when engine reaches norm operating temperature i thought the logical thing to do would be to check the turbo cooling system (the water one)

i put in a new water temp sensor in, level sensor works fine and rad fans come on and off ok. and no visible leaks. hmmm!

so having checked this system (twice) i can only assume that all is working normally and this isnt causing the problem.

-only thing i did notice, which may be normal, is the tank connected to the side of the intercooler with two pipes going to the radiator sometimes boils (no leakage just boils in the tank) when driving for long periods - is this normal??



anyway, on to the turbo and vacuum system it is then!!

i checked all hoses for boost leaks and made sure everything is tight etc, - nothing, all seem ok.

on the vacuum system the egr soleniod and pipes have been disconnected but from what ive read this makes no difference to the car its mearly an emmisions thing. -- does any one know if this is true??

now the the lack of power is when you get to 4500rpm when the boost should start to flow through both turbos but im gessing it doesnt, judging by the way the car performes, so im now thinking that its the actuators or solenoids that arent doing what they should do when i rev past 4500rpm

--as this process (valve opening to allow boost through both turbos) is partially controlled by the ecu will a diagnosis checker reveal the problem??

only thing is im not 100% sure what i should be checking for (still a noob really!!!)

had air filters, pipes (vacuume and boost) in bits several times and looks as though all the 'non moving bits' of the turbo are fine - no crack or visible deteriation etc.

does any one think im on the right track by checking the acuators and solenoids??


this is doing my nut in :wallbash: - any pointers/suggestions are much welcome.

I do not think it is you Turbo. If you read on this site you will see there are a few of us having the same problem. I also have no power over 4000 RPM when engine is at temp. 1984 GSL SE 13B, I have changed the ECU , Throttle sensor, plugs, fuel filter and pump. I still have the problem.

Check it is the Chek engine ligth on , check the intercooler for a leak, I think that you have a problem of waste of boost , ussually the hose that came from the turbo just at the end of the Y pipe get bad , you have to check it cause you not gone see it installed into the car , just take it off and check it.

Yeah interested in whats happening to your car. Do you get full boost in everygear as long as you dont go above 4K rpm?

Works great when cold, but falls flat when warmed up... I'm no expert in fuel injection systems but to me this would suggest a faulty sensor (temp?). When cold, the engine runs on a predetermined setup for fuel/air. When warm, the computer takes over and starts adjusting based on input from various sensors on the engine. Bad info from one of those sensors will result in all kinds of bad running when warm. Just thought I'd throw that out there...

Oh yeah, I see that you replaced the water temp sensor, but there is also (I believe) another temp sensor that is just for the input to the computer.

You probaby have a cracked line/turbo pre-control selonoid. Check in the FD section under the stickies/faq's for how to test the sequential soelnoid's. What do you mean by "using high octane fuel helps"? What octane were you dumping in before? I hope not 87 or 89. If you did dump low-octane regular or mid-grade fuel into the car, or have a clogged fuel filter, you could have a blown motor. Start with the easy stuff first. You can do the poor man's compression check by pulling your fuel pump relay fuse, pull one leading plug, turn the motor over and listen for three even "woosh's". replace the plug and remove the other leading plug. If either has uneven woosh's, or is missing 2/3 woosh's, you're looking at a new motor. Post in the FD section for more help

Damn noob. The -SE and the FD are COMPLETELY different. Please, don't be a troll.

Read the FD FAQ's and Stickies. These will help you IMMENSLEY