ralphenn

Recently I bought a european Turbo II Convertible(89) with a jumping idle issue (jumping between 1300-1500rpm), because i thought it wouldnt be somithing major. I readjusted the TPS, replaced some broken vacuum lines, fixed O2 wiring (code from ecu), which made it a lot better, it started hot or cold(10°celsius) without giving any throttle, just the juming idle remained(only when ut to temperature). I also tried to unplug the BAC, the AWS and air supply valve without any difference. So i started searching some more leaks, i read here that sometimes the pipe to the turbo can crack sothat there will be unmetered air sucked in, i removed the airbox, the afm, the bov and that pipe with the result that there where no leaks, then put it back together und changed the spark plugs.
Now comes the real problem, I started the car, fired right up, but without the cold start of 3000rpm just 2000, after 2min the rpm goes to 2500(stayed there) and another 2 min later i saw the turbo and downpipe glowing tike a light bulb and maybe 3 sec later oil down there catched on fire, I immediately i shout off the car and took a fire extinguisher. I was really shocked, something like hat never happend to me. The next day i removed all the extinguisher powder and started looking for the fault. I check the spark--> all 4 working, checked the knock sonsor cable (touched it a lot when chaning the spark plugs) because i read it can cause retarded timing, checked everything i have touched and tried it with the old spark plugs, its still doing the same thing (i shut down the enigne when I see the turbo starts glowing a bit). The ecu also has no fault codes stored. i read that retarded timing can cause that, but can the timing just change from 1 hour to the other? i dint even touched the cas cable.
Please help me i have no idea what i should do or what else could cause this and i really dont want to destroy the car or burn down my house. (This is my first post ever on a forum) im from Germany so hopfully you can understand me
Thank you

FrankV702

iTrader: (14)

Did you check timing with a timing light?

What exhaust system is on the car? Did you check to see if your cat is clogged if you’re running one?

FührerTüner

iTrader: (5)

All the stuff Frank asked^^^^^^^ and

What are your AFRs? Are you sure you dont have a misfire? Stock ECU?

ralphenn

Sry forgot to metion, the car is completely stock, i thought about the cat, but the problem came within an hour, could it happen this fast? Im readjusting the timing right now and checking it with a timing light after that, lets see if that helps.

FührerTüner

iTrader: (5)

Pull your plugs while your at it and post pics.

ralphenn

I set the front leading spark to 5° atdc, results:
started right up and hold 3000rpm for about 20sec then down to 2000rpm, and after maybe a minute it went up to 2500rpm (like before), i think whatever causes this is also responsible for the glowing.
I post pics later (i have guest now)

insightful

sounds like your thermowax is stuck, however you cant set timing properly with your idle that high anyways which is one part of your problem, but it still sounds like you have a blockage in the exhaust.

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iTrader: (5)

Also besides the idle speed, you need to ground the green check connector.

ralphenn

Leading spark front rotor
Trailing spark front rotor
Leading spark rear rotor
Trailing spark rear rotor
It looks like they all fired, but they didnt really run much

FührerTüner

iTrader: (5)

Those are clean as ****. They must be new right? Were any of them wet?

ralphenn

Thank you for your fast replys
ok im going to look after the thermowax
But any ideas why the rpm rises after a while?
Even when I unplug the aws and bac

ralphenn

Strange that i could dive it 300km home without any problems besides the jumping idle on Saturday. I will try to get a look in the cat tomorrow

ralphenn

yes they ran maybe 12mins, on the leading plug front rotor there was a minimal amount of oil, rest were dry
​​​​

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iTrader: (5)

Just a hunch, but check your secondary throttle plates, and make sure theyre not stuck open.

Also try unplugging the TPS and see what happens.

Also spray some brake cleaner or carb cleaner around the engine bay with it running. If the idle changes you have a vacuum leak.

ralphenn

ralphenn

Ok blocked off the thermowax and disconnected the tps
It started normal with 3000rpm dropped then down to 1200rpm and after 1 minute it went up again as before, after i shout it off the exhaust direktly made a loud tiking sound.. the car ran maybe 1.5min
​​

ralphenn

I already tried the brake cleaner, but didnt made any differences.
could it be something with the afm? because i had removed it before the problem occurred

FührerTüner

iTrader: (5)

Yeah that was my next guess, AFM. Either that, a stuck injector, or a clogged exhaust like insightful said. But if it was running fine before, its probably the AFM, or the wiring to it.

Youre running rich and your idle is high.

ralphenn

Ok I remove it again maybe I see something strange, but I dont get a afm fault code, now just the tps after I unplug it.
It seems to be the original cat(70k miles on the clock), so i dont think its pretty inside there

FührerTüner

iTrader: (5)

ralphenn

ok i removed everything and checked the turbo,
​​​​​it has a ton of radial play and doesn't spins that well, so it seems that i destroyed ist, could this be the cause? On may drive with the car it produced boost so didnt thought of that.
the wiring to afm has noch cracks or something like that, afm also seems fine

FührerTüner

iTrader: (5)

Thats a problem, but its probably not your issue.

If you had any vacuum leaks, your car would be running lean. Your glowing exhaust tells us its running rich.

FührerTüner

iTrader: (5)

Um by chance, did you make sure your plug wires went back on right?

Ill bet you put the trailing on the leading and vice versa

ralphenn

Ok measured the afm, everything how it should be.
When i drove it the turbo doesnt seemed to broken
but I never drove a rx7 turbo before, so i dont know how it should feel. Maybe it went worse with the high heat but then it cant be the problem.
what you suggest to check next?

ralphenn

Yes checked that, i also have blue wirers for trailing and black for leading, upper ones Trailing and bottom ones Leading, right?