eightman1977

Okay, so today I was driving down 695, and I got into it a little bit, about 3/4 throttle and hitting about 10 psi. Well at one point when shifting from 3rd to 4th it let out a cloud of black smoke.

So as soon as I can I pull my RX-7 off to the side of the road. First things first I checked the oil and it was fine. Second I check my temp on my Apex'i FC Commander and it was at about 79 degree C. I took a look at my charge pipes inside the engine bay and they were still connected, however, I can't see behind the bumper.

So I get the car back home, and as I'm driving home it still has plenty of power to move along in traffic, and easily maintianed 60mph. When I parked it, I left it sit to idle and it's putting out a grayish cloud of smoke, and so I went back and sniffed and it has a HEAVY scent of fuel, but my car did run somewhat rich to begin with.

I spoke with my buddy Bill and we came to the conclusion of what it could be. My first thought and what I'm hoping it's not is the Apex Seal. However, I blew an Apex seal once before and the car could barely get out of it's own way. The car still has power to move.

Bill mentioned that it could be a fowled plug. He stated this because of the fact that I mentioned the cloud of black smoke, and the fact that the exhaust note changed from the normal pissed of wasp, to a slow *** supra. So I shut the car down after getting home, and check over things again. Checked the oil, it was fine. Checked the temp it was at 80 degrees C, so that was fine. So I started it up again to confirm the smoke coming from the exhaust, and this time it was having difficulty staying at idle. So I pressed the gas slightly and it took it a second to rev up to 2,000 rpms. I'm leaning toward this situation the most. Because I understand the fact that too much gas may be flowing into the rotor housing and with 1 of the plugs being out it may not be able to ignite the mixture and therefore resulting in my idle issues. The car also boosts just fine, as soon as this happend I shut my boost controller down and prevented the car from boosting anything over 7PSI to lessen any chance of possible further damage.

The third option Bill mentioned was a charge pipe could have blown off behind the bumper and I can't see behind there anyways.

So if anyone can add some information please do so. I'm hoping that it's just a fowled plug and nothing more. Tomorrow Bill will be getting his compression test guage and we'll be doing a compression test one day this week to confirm if the engine still has proper compression in each housing. Also just to be 100% sure, what should the compression be for each rotor housing, and which plug do you remove to install the compression guage?

Thanks for any help people, and hopefully it's option 2 or 3, cause I can't afford option 1 if that's the case, unless people can donate a part here and there. LOL

eightman1977

Bump!

eightman1977

Can anybody please help?

DaveW

1. Please post a list of your modifications, if any.

2. I have never heard that a cloud of black smoke alone would indicate a blown apex seal, so I think the probability of that is low. Since it happened suddenly, and while you were under 10-psi boost, I would suspect that a secondary injector has somehow stuck open. This would cause a fouled plug, but I doubt seriously that a fouled plug would cause the original black smoke.

Do you have any signs of the catalytic converter overheating? This would also be a sign of excess fuel.

Howard Coleman

iTrader: (6)

probably the reason you haven't gotten alot of responses is that it could be a number of things from your description of events. the initial event was black exhaust. that's fuel related. if it was a water O ring it would have been white.

yet at idle you see grey... that could be oil or coolant.

there are a number of possibilities many not fatal. you will just need to work thru them and eliminate each...

keep us posted as to what you find. the more info the more help you'll get.

good luck,

hc

eightman1977

The FD is pretty highly modified. 880cc primary injectors, 1600cc secondaries, 4 inch exhaust all the way back, no cat. PFSupercars Turbonetics package. I'll start inspecting tomorrow after work, especially since I don't have soccer tomorrow. Thanks for some of the info.

The motor is also pretty freshly rebuilt, with only about 5,000 miles on it. Also I'm doubting it's coolant, because the fact that the car didn't over heat.

Oh an important note ****I'm not running a catch can yet**** so the crank case presure is going right back into the turbo and thru the intercooler and back into the engine.

Does anyone think it could be a blown turbo?

eightman1977

So, I installed the new plugs today and still the same results. However, when I first started up the car, it turned over pretty easily and was able to rev relatively easy. So I shut it down, and pulled the intake off to check out the turbo itself, there was no shaft play at all. So I had my girlfriend start the car again, and this time it was hesitant to rev, and there was still an overwhelming scent of unburnt fuel.

Later this week, I'm going to attempt to do a compression test. I'm still hoping for the best, but I'm beginning to think the worst. I seriously hope I'm wrong, because I can't afford to fix the engine this time if it is an apex seal. I guess I could do the simple thing and pull piping off the exhaust side of the turbo and see if there's any damage to the blades.

However, I'll keep everybody updated. If there's any other suggestions from anyone, please feel free to let me know. Thanks