monzue

So, I was walking through the forest one day, and stumbled on a turbo rx-8 with the keys in it. What was I to do? What would you do? Take it for myself of course! The catch happened to be though, that it was flooded and I didn’t have my daily supply of washer fluid on me.
Description of car:
Manual
Remanufactured 13B Renesis with 3mm apex seals
Interceptor-X
Greddy T618Z Turbo
Greddy Profec B Spec II Boost Controller

This turbo Rx-8 was purchased in the for sale section of this forum from epitrochoid Kudos to epitrochoid for helping me through my first de-flooding procedure. He kept the car Clean!

This is my first post in here. This is going to be some serious rambling. Bear with me, I have some questions. This is my current situation: My car will not stay running. The car is very, very difficult to start. I may have to go through the de-flooding procedure 2-3 times in order to get the car to start. What is this de-flooding procedure, you ask? I’ll tell you at the end. So I get my car started. I’ll keep my foot on the accelerator and keep the rpms at around 2000-3000 until the car warms up. ~ 6-7 min. Then I’ll give ramp the rpms up and down, fast and slow. Car runs smooth at 3-6000 rpms. Try to give it gas to make it go above 7000 rpms and the car will not let it. Almost as if it is throttle limited. Not warmed up enough? Next, I notice that below 2000 rpms the motor shudders and seems to shake. No flashing cel light though. Oops, the car drops below 1500 rpms and promptly dies. Will not start. I was watching the greddy boost controller during this and noticed that when I would ramp up the rpms, the peak boost seemed to be around 4psi with some peaks reaching 13 psi! Does this make sense?


I have successfully de-flooded more than 8 times in the month which I have had the car. So I put in new spark plugs, I thought it would help, but now the car is acting very different. The only change I have made is I have put in the Mazda factory plugs (Mazda Part no. N3Y3-18-S30. Set of 4 NGK Iridium Plugs: 2 leading-RE7C and 2 trailing-RE9B.) Note: I found out today that having this configuration of spark plugs is not good for a turbo. All the plugs should be trailing. Not 2 leading and 2 trailing. These plugs replaced NGK spark plugs (model: 5255 BUR9EQP). The obvious difference: When driving hard and having a slow shift, the car used to backfire loudly and shoot flames. With the new plugs, the car will no longer do this, or it is a much smaller backfire. I had the plugs in for a week… Two days ago I was driving hard and then came to a stop sign. I stopped, was idling, then the car died. I had to do the 1st step in the de-flooding procedure to get the car started again. The car died again in a parking lot. Later I got the car started again and was idling fine for 10 min, then I touched the gas and the car died. Now I’m in my present state. Note, the car battery is not a factor here, because it has 640 CCA and I had a battery charger hooked up most of the time I was cranking. I’m at a loss now, because I have gotten my car running 2 times in the past two days, and both times the car died idling after the engine had gotten hot. Then the engine would not start. Note: The engine would not start, but seemed to spin much, much faster than when cold starting it. I cranked for some time with the fuel plug disconnected just to make sure no fuel was getting in to the engine.
I think that I should switch back to some new 5255 plugs.

One thing that I am not 100% sure of…. Does the Interceptor-X stop fuel flow into the engine when the accelerator is to the floor? My current belief is that it doesn’t. So in order to stop fuel flow I have taken up the rear driver seat (just yanked on it). I removed a metal plate with four screws holding it down. Under the plate is the fuel line, fuel filter?, and the wiring harness for the fuel pump. In order to stop fuel, I have been pulling the plug. When I want fuel to start flowing, I will reconnect the fuel pump harness, sometimes while cranking.

MazdaManiac

iTrader: (3)

Compression check?

Blown apex seals make the motor hard to start and idle.
Could just be a change-of-season issue with the Int-X, though.

Dookie_Rx-8

retune the int-x? i only say that because i heard few turbo rx7s having similar problems then having a tuning guro only to fix all their problems just by tuning.But then i wouldnt really know anything bout stuff like that..has the past owner always say the car acted like that?

monzue

Ok, The tune on the car should be fine. The car was last tuned at the end of December, with a conservative tune. I believe that the previous owner had no trouble of this sort. However, ever since I have had the car, starting performance has degraded over time. I have taken the Inteceptor and factory computer out of the car once, because I dropped a screw below the battery container. I put everything back and the car ran fine. I think that the tune should be retained in the inteceptor even after disconnecting power, correct?

Compression check is forthcoming. I have looked around for a compression meter, and the one that seems to be recommended is the meter from Pep-boys. Not having a Pep-boys close, I called them and got a meter part #. (Actron CP7821). Not sure if this is the meter talked about on the forum. This particular meter has a black rubber boot at the end and is meant to just press into the spark plug hole. I called around and no one has this particular meter, however some ppl do carry the CP7827 and the CP7828. Maybe the CP7827 will work, since it has a pressure release stem valve button on the side of the hose.

Side Note: after pulling out the spark plugs after a few days of driving, they turned black and had a black carbon ring around the edge of the plug. Some of this residue was hard to remove, and some seemed to flake off.

StealthTL

iTrader: (1)

I am certainly not qualified to advise on an FI setup, but this is what I would do;

- first you got to get it running - something is VERY wrong.
The black fluffy plugs indicate WAY too much gas, check the vacuum connection is intact ALL the way to the Int-X. Disconnecting the fuel pump harness can still let in enough gas to flood the plugs, there is a LOT of gas under pressure in the system, even with the pump off, you need to disable the injectors like the ECU does.

Remove the Int-X, then try and deflood/start. I would also put the proper plugs back in, I've never heard of using 4 trailers.....
Until you get it idling you are going nowhere.

S

monzue

literally. Ok, I checked the compression with a Actron CP2827 guage. I took out the valve stem. Now, when I tried to crank, I got a bouncing needle. On the front rotor, the needle would bounce to 60 PSI. On the rear rotor, the needle would bounce to 35 PSI. I am currently trying to increase the compression on the rear rotor by the black art of fluid injection in the motor. Haven't managed to start today. Also, I noticed that with the factory spark plugs, the plugs have a small piece of metal that hangs out and above the spark plug positive stem. However, the spark is not made between this overhang and the stem, rather the spark is made to the inside wall of the plug. Not sure if this is by design or not.

HMMM. THIS IS NOT GOOD... I just checked what it should be, and I am getting that I should see ~120 psi?????? at at 10:1 compression ratio? is this correct?

When I measured Compression, I had a foot long hose going to the guage. I'm sure this would bring down the measured psi, but I don't know how much.

monzue

Ok, I have been able to start my car. I let the car run at 3000 RPMS for 10 min and then let it run at 4000 rpms for several minutes. Then I let it run at 1500 rpms for 5 min. At the 1500 RPM range, the car runs rough, like the engine is spurting. I try to get the car to idle, but no luck. It promptly dies. Next I took out the Inteceptor-X. Now the car will start quickly. But it will not idle. Anything below 1200 RPMS and the engine struggles to stay alive. If I release the gas completely, the engine promptly dies. About 2500 RPM the engine runs fairly smooth, but anything above 3000RPM seems to really make the engine sputter. I was trying to hit 3500 RPMS, but never hit it.

I don't seem to have an obvious vaccum leak. My MAF is really really dirty though. I have the greddy turbo intake with the blue air filter, and it is dirty with oil on the bottom. Do you think a dirty MAF would cause this type of problem?

mysql101

He has Epi's car, his engine blew up, so it now has a replacement engine + 3 MM seals.. I think he also has the mazsport return fuel pump too.



What I would recommend doing is unplugging the int-x completely. Your car does not need it to start up and idle.

So pull the int-x and see how things run. If it starts up normally, then you know what the problem is. As long as you aren't boosting, you should be able to drive around and see if there's any improvement. That said, I suspect you'll find the car is still a pain even without the int-x in use.

Next thing is to check your coils. My car used to bog down a lot at low rpms and die. The coils were shot. They're just as easy to replace as it is to unplug the int-x. Takes less than 10 minutes. Unplug them and see if the bottoms are burned. You can buy new coils for about $20 each.


I thought the car was given to you with a really rich int-x map for break-in. Are you still running that map, or a normal one?

mysql101

If you removed the int-x, a dirty maf will cause idle problems since your pcm will make use of it.

the int-x controls fuel when it's plugged in, and does not use the maf, so it wouldn't effect it.


get some good maf cleaner from your local auto store, spray the crap out of it, and try again..



far as boost leak, what does your boost gauge read when you are idling? should be -18 to -20 area. if your boost gauge doesn't say, your int-x software will tell you.

swoope

iTrader: (5)

and as always check all you rubber connections in the turbo loop.

right jason?

beers

nycgps

iTrader: (1)

I've had no experience with Turbo, so Im not sure what the problem is.

but yes MAF cleaners are cheap, I just got mine for what 3.99 or something couple days ago. So give it a shot. it doesnt hurt to try.

monzue

I replaced my coils with new ones. That didn't help.

My problem: In order to start the car, I have to put 10-20 cc's of oil into the engine. Once started, The car will run fine, but will not idle. If I take my foot off the gas, the car dies. Once the car dies, it will not start again, and I have to put more oil in to get it started. Maybe my MOP is bad? I do have an aftermarket MOP. Maybe I have carbon buildup? Bad gas? Bad apex seal?

So now, I am stuck, and may have to take the 8 to a shop. Anyone know a good shop in Tennesse, Alabama?

olddragger

iTrader: (3)

got your pm.
Please see mine.
If injecting oil into the chamber makes for easier starting--thats an indicator of compression problems. It doesnt sound good to me. The compresson checker you bought--it is for a rotary engine--correct? You also have to make sure you have spun it to 200-250rpms before the check is good.
Aftermarket mop? Do you mean Racing beats mod for the mop or the differant oil source for the mop mod?
olddragger

monzue

Thanks olddragger.

I'm sure the compression checker is not necessarily made for the rotary engine. However, there was a valve stem at the end, which I removed. Now the needle would bounce. one bounce for every compression pulse. Could have easily been 4 bounces / second which would equal 250 RPMs. all the bounces were even. Just low at around 60 PSI.

I don't know about the MOP. I'm going to have to ask Mazsport about that when I am down there, since I have decided to trailer my car to Orlando from here.

Yes, I have the upgraded fuel system. I have had my car tuned by Mazsport.
I have my boost controller set limiter setting to 8 PSI. I have no Idea of the cause of this. Will update later.

MazdaManiac

iTrader: (3)

From what I've seen, a conventional compression gauge with the schrader valve removed will show exactly what you describe on a good motor.
That is, 60 PSI "bumps" for each chamber. The low number is due to the slowness of the gauge and the pressure seeping out before the needle goes to full deflection.

rkostolni

Actually, this is an odd coincidence. A friend with a turbo'd 8 just left my house with this exact problem. The car starts hard and won't idle. You have to hold the rpm's over 1500 to keep it running. I did a compression check and it showed around 60psi, which led me to believe it had a blown motor. However, after taking it for a drive it definitely has as much power under boost as mine. I was skeptical about how a car with half its compression would still have power.

I checked for spark on all 4 plugs, and checked the AFR. Both were good. We also ran it with no exhaust just to make sure it wasn't a clogged exhaust. We ran it with the Intx and then from the factory computer. Not much change. No significant CEL's were stored either.

Any idea's from anyone. I'm baffled!

swoope

iTrader: (5)

i would run about 6 oz of premix in it and see if it changes...

my guess is damage from before the turbo with the old flash is starting to rear its ugly head..

beers

monzue

Swoope, I don't believe that this could be the problem in my case, because my motor is newly remanufactured. Granted, I don't know what the motor went through though, before the rebuild.

I know that My exaust is not the problem also, because I had my cat replaced with the RB midpipe. Something funny is though...... When I looked at my cat, someone had already completely gutted it!!! I could find no trace of any cat element. Wat a waste of $240...

Now, I also did get a reccommendation on this board to swap out the Int-X and go directly to the OEM computer. I tried this, and the engine started fine, but ran completely rough /w vibration. The reason for this is that I have the upgraded larger capacity fuel injectors. I didn't think that was the best for it, so I didn't continue with the OEM computer.

and THANKS MM for the HOPE that my engine MIGHT not be the problem!

dannobre

iTrader: (3)

Sounds like a tuning issue. Are you sure the correct map is loaded in the IntX??

dastallion951

either someone didnt tune the idle at all on the interceptor x................. or check for vacuum leaks, check all clamps and hoses on vacuum ports..... or u know what it might be check ur injectors............one might be stuck open........... check that if u got access to a scanner that can open n close actuators...........

dastallion951

no its just why type extra if u dont have too.............n whats the big deal anyway abbid just tryin to help a car enthusiast thats havin a problem, what r u the english n punctuation teacher on the rx8 forum.........

MazdaManiac

iTrader: (3)

I love bad advice.

swoope

iTrader: (5)

true, but it depends on the flash in the ecu.. or if you have been running premix.

beers

MazdaManiac

iTrader: (3)

Look for a collapsed, pinched or otherwise inhibited vac line to the Int-X.

MazdaManiac

iTrader: (3)

Nice. I'm still there. I go home in the morning.
I met up with RG and Brillo last night. I wanted to go to a beer tour today, but I got tied up with my client for way too much time.