2nd Generation Specific (1986-1992) 1986-1992 Discussion including performance modifications and technical support sections.

Repairing a mess of an engine

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Old 05-23-10 | 12:51 AM
  #1  
Chris Boots's Avatar
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I blame the TPS
 
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From: MT
Repairing a mess of an engine

Newest car in the shop is an 88 TII with a ported engine with 3mm apex seals and a bunch of other valuable internals that I'm hoping aren't harmed.

Engine has 80 psi and 6K miles on the engine. A little low yes, but we're at 3500 feet so thats acceptable in turbo rotary engine terms I guess. Engine hadn't been ran in 2 years but fired right up when we first cranked it to get it on the trailer. Before it was parked it was smoking really bad.

Well, the lines off the oil filler tube were capped and the one at the tube's base was melted off and created a rubberish cap there too. I put the line closest to the cap to an oil bottle, and the other one hooked back up to the charcoal canister line (which was also plugged but it was no match for the air nozzle). So now the car only smokes for a few seconds on startup but no big deal. Though I had the problem fixed but no.

Retarded the timing a bunch to make it drivable and got it to the shop and by that time the Rtek 2.1 PDA was charged up and I downloaded the map in the ECU to it. The car dyno'd once before it was parked at 300whp so the map is fine I'm sure and I'll just leave it alone. Ran horrible the way home though, my FB could have put this car to shame. So it had 30+ oil psi on the way home says the gauge and by the time it got home it was running worse and the gauge read 0. Tested the gauge and it works fine. sender? I don't know yet. I have a spare sender and I'll be putting a reliable mechanical gauge on it soon. I seriously hope it doesn't have 0 but I'll pull the CAS and look down inside to see if anything that has to do with the oil pump chain and gears. Would make sense though. Can't hardly give more that 30% tps/thottle and it knocks and sounds like it detonates. Oh joy, another rx resurrection. Ran like a bat out off hell when parked but smoked, now won't get out of its own way.
Some specs for thought,
full streetported engine w/3mm apex seals, S5 milled rotors
Fidanza lightweight flywheel
Mazdaspeed 3 puck clutch
720/720 injectors
Rtek 2.1 management N332 ecu (s4)
S5 lower intake manifold no emissions
S6 upper intake
Knightsports RF320 turbocharger (comparable to a BNR stage 3 or4) wasted at 10psi
FMIC
walbro 255
Racing Beat 3in exhaust system

Pretty basic mod TII setup

Any ideas? check this and that? Will be verifying my oil pressure idea around noon tomorrow
Old 05-23-10 | 01:01 AM
  #2  
misterstyx69's Avatar
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From: Smiths Falls.(near Ottawa!.Mapquest IT!)
Chris.I have Basically the same setup.
FC tii Engine with a FD upper and S6 Throttle body and TPS.
..Try something just so see If this helps( as it did 'wonders for me)..take the TPS off the Throttle body and let it hang(but keep it connected to the harness),,then go for a quick spin,..see if it Runs better than what it ran like before.
It's only a Quick 2 minute "job" so "amuse me"..
My car ran like **** when i had the TPS ON the Throttle body,,I took it off and let it Hang,But still have it hooked up and it runs Decent,.the AFR"S are within Safe limits too.It baffles me,.but If it is Safe on the Fuel,I am Ok with it.//Until I can figure it out or get more time to look into it.
Old 05-23-10 | 01:05 AM
  #3  
Chris Boots's Avatar
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I blame the TPS
 
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From: MT
< Like my avatar says "I blame the tps"


I'll amuse you and try it out and let ya know. I have a NKG AFX wideband in it to monitor the afr's
Old 05-24-10 | 11:20 PM
  #4  
Chris Boots's Avatar
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I blame the TPS
 
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From: MT
No dice, hardly any difference. Only thing I noticed was it was harder to make it idle from being rich. Smoking bad again, leaning towards cracked rotor.
Old 05-25-10 | 12:14 AM
  #5  
arghx's Avatar
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From: cold
pull the oil filter and crank the engine over. does oil come out? plugs good?
Old 05-25-10 | 12:17 AM
  #6  
Chris Boots's Avatar
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I blame the TPS
 
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From: MT
Oil would come out. Forgot to mention, bad sender. Put a new sender in and I'm seeing about 30psi at idle and close to 100 above 4K
Old 05-27-10 | 12:04 PM
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sharingan 19's Avatar
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From: Jacksonville, Tampa & Tallahassee
Whats the condition of the fuel system? Fuel likes to varnish if it sits too long, and thats not kind on pumps or filters, It'd likely be worse if it was running premix before.
Old 05-27-10 | 09:01 PM
  #8  
Chris Boots's Avatar
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I blame the TPS
 
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From: MT
Yeah I thought of that too... The car sat for 5 months with no stabilizer in it and a 1/4 of a tank of gas. Fired right up to get it on the trailer. Thought about fuel pressure, then saw that it was still right where it should be when we hooked a gauge up to it. Has a walbro 255 in her and has its own 10 gauge positive going from the battery with a breaker to it along with a solenoid between it that is activated by the original fuel pump wire so it retains its automatic part of it all. Drained the tank, filled it with actual non ethanol 91 octane and a booster, so lets say she's got 93ish octane in her now. It starts up right away, idles at 850 rpms-ish (ported, 750rpm isn't an option anymore) and the rtek tells me I've got 16 in vacuum at idle so thats great. Most of my turbo engines sit at our 13 for vacuum. Anyways, I've got another engine for it, the other engine is an S5 that is streetported but has basic internals compared to the engine in the car now, ie- 2mm apex seals compared to 3mm, stock crank as compared to renesis crank, etc etc. A mild mod motor, but has good compression. Its just a keg right now, but I have all the parts extra to put on the engine and make it so its just a drop right in engine. I think I'll do that and see how it goes.

Furthermore, the race engine smokes really bad now and one last thing I'm going to check is the vacuum lines to the oil injection nozzles and if they check out fine, then I'm pulling the engine out because the only other reason is something internal like a bad oil control ring, or worse a cracked rotor... again (its cracked a rotor before a few years ago and we then went with a different company to machine another 3mm rotor). Cracked rotor would explain the smoke because the rotor is filled with oil and maybe its running the way it is. But damn I don't get it, I should at least be able to boost it normally even with a cracked rotor like I could last time or if its a bad control ring it would run fine but smoke really bad. Stupid thing about rotaries is the part where you have to spend upwards of 300 just to crack the engine open and then seal it again. I'll have to give pineapple racing a call and see what they can tell me about a little cheaper engine o ring seals because the ones I buy from mazda aren't getting any cheaper.

Suppose the streetported 2mm S5 engine I have is good up to 300whp I guess, but not the rpms and power I had built the other engine for. Something to put under the hood in the time being though since it takes me about 30minutes tops to pull one of these engines out.
Frustration is the word I describe this car with right now.
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