Phantomkid

Car: 1988 mazda Rx7 vert
Engine: used t2

Problem: Car idles and runs rough. loss of power

Hey guys im at my moms for the holidays, and get to work on my car. Shes running rough. Smokes from the tailpipe, and does not have power. As for the smoke it does not smell like coolant, and there is not a loss of coolant in the system. I had but mystery oil in leading holes because it sat for awhile, but that was yesterday and ive run the motor a bunch. The engine is pulling about 15in at idle at stayes the same maybe 16in with increased rpm. Out the tailpipe you can feel very strong steady pulses. The engine has good compression about 110 each face. i have set timing to spec. i clamped the timing gun around the 2nd rotor trailing and there is no light. I hooked up a inline spark plug teser light thing haha and it pulsed a steady light. the leading lights the timing gun but is not steady it seems to miss. I may check the CAS to make sure it is aligned correctly. When i pulled the spark plugs i notice the 1st rotor is usually clean and if dirty its caused by flooding. The rear rotor plugs are black, like its running very rich. Im about to hook up my LM1 to see what the fuel ratio is looking like and ill get back to you. The resistor in the engine bay i believe is closer to lean. On all the way lean it pulls more vacuum but the engine does not sound as solid. Any ideas guys...Thanks for all the help
..Brian

Phantomkid

Hey guys.. no ideas???? I was not able to hook up the wideband the sensor does not mount into the stock threads i will need to weld on the additional bung. the vehicle is still smoking seems to have a tint of blue. As mentioned i did put MMO in the leading holes, to help build compresion but dont think thats the cause of the smoke. I changed the oil because the oil was smelling like fuel, i was told if the car floods you should change the oil to help preserve seals... Anyway what ive checked so far that looks good Fuel pressure measurement at idle is 35psi slightly lower the spec. at accel it bumps up to 39 psi with key on engine off its 40psi( i know my maf is slightly open but still checks out to spec) the fuel system holds 30psi of pressure so i dont believe the injectors are leaking. I pulled the spark plugs again the seem to be damp, seems to be fuel. So it seems somehow i am running rich still. I adjusted the tps to spec, im going the check voltages at the ecu pins in a bit, im also going to check for freeplay in the turbo charger, and read fuel pressures and vacuum on a test drive to see if shes making an boost at all. Any ideas guys would be great.. thanks
.Brian

Phantomkid

alright im going to change the problem to:
loss in low end power/ rough idle.

I test drove the vehicle and allowed the rpms to rise to 7k at 4k the engine starts making boost and power is back although i do not know if this is its full power potential. Before 4k no power first gear takes awhile to spool. after the test drive i noticed smoke coming from the area of the turbo looked to be near the mount from the turbo to manifold. Things i have been pondering as possible causes. Maybe the turbo is siezing, could explain the low vacuum readings. possible a problem with the fuel injectors although they were cleaned before install. I have 800cc injectors i will be installing shortly just need to get them cleaned and flow tested. Any other ideas guys once the engine cools im going to pull the plugs and check them also check free play at the turbo. thanks again guys..
.brian

n1ko

I would also say to check the turbo. Do you have a boost gauge? Is it boosting fully at the higher rpm where you said it had power? I can't see the turbo being so sticky or the compressor wheel hitting the inside of the housing so hard to make it idle rough, but if your turbo seals are going then that would probably generate smoke.

Phantomkid

updates...
the car still hates me. I tried switching in my n338 ecu.. no change, no faults codes found from either ecu. I pulled the intake hose off the turbo the turbo feels solid and the compressor fins look good. i pulled the plugs again after the test drive and again the rear plugs are dark in color and the front plugs tailing was wet and leading looked fine. I am starting to think there is a fuel problem. when i pull a vacuum line the engine does not die it actually almost sounds better pulling 9in of vacuum. if i spray starter fluid in the vacuum hose the engine dies right away. So i think im running to rich. I wish i was able to get the wideband in, Im tempted to trim some fuel using the emanage but im afraid without the wideband so i might have to wait.... Any ideas... thanks
.Brian