Hello guys,

So I had my car flooded ( i forgot to do the 3k rpm procedure (dumb me)) and I took it to my mechanic, since the battery died and couldn't do more, (he isn't good with rotaries but did some rx7).

He tried everything to deflood it, cleaned injectors, fuel pump, put oil inside rotors, and changed coils, plugs, wires, but nothing.... he couldn't deflood it, until I went to him and deflooded it..... (which is dumb i'm not a mechanic ( I just pressed the accelerator after it turned on)).

So after deflooding it the car doesn't stay on, like it tries and the rpm go up to 1500 and down below 700 (idle hunting) but not always.... let's say the car went crazy so now she either dies at idle or hunts at idle or runs fine at idle.

after that he tried to see E-Shaft, MAF, air filter, and recorded the air input and fuel input but it was all ok. He tried to do something more but nothing it didn't change at all.... So I took the car away and tried to find another mechanic.

In 4 days I drove her like I did until now and it was crazy and a little bit sad how she would die.... after taking her out of garage she would die, coming to a red light she dies, changing gears she dies, but after a bit of driving she changes, coming to a red light she tries to stay on but still dies, after REALLY hard driving she goes normal, no shaking, no idle hunting, clean 800 rpm idle, and she stay so until I turn her off and on again (i've let her stay like this for 1 hour and all good). So lets say she dies more on cold engine than hot.

After the 4 days I went to another mechanic, at which I did a compression test with (rotary compression tester) and it was low but not too low (front 71,72,60 - rear 86,92,89), he's still trying to figure out what the problem could be.

-Idle after deflood and after hard driving.

-Hot start after deflood.

Idle hunting and dies.

Dies after letting go of gas pedal (the next day after deflooded)

Idle hunting (day after deflood)




So I wanted to be sure if it's a problem from low compression or something else. Thank you.

 

first: 3k rpm procedure??? if all is health you can start and stop your rx8 all day cold or hot and never flood. I do it all the time

second: I'd start with the easiest thing first. Get that check engine light scanned for code numbers

third: Comp. numbers are meaningless without an rpm number ( fyi the one rotor going 70,70,60 isn't a good sign)



fourth: When you make a help me thread give us any and all info on the car. is it the original engine? all 118k km

fifth: If you haven't already done so, give the new owners thread a read, and also try searching the forums here for a hunting idle

sixth: Purley my opinion based on info provided, your engine is fooked, time for a reman

 

Front rotor has lost compression. Needs a replacement engine. 60 PSI is like 4 bar that's toast.

 

^^ this. I'm not sure what your mechanic is trying to figure out beyond that.

When was your last compression test before this? Because I've had compression test results show low, and in 6 months they were back up.
Did you have any other symptoms before this flood?

Reading this story, I was going to say the car just needed to be left along to idle after the battery was plugged back in. It needs to learn to idle, otherwise random dropouts happen. But it should still have learned by now.

It's possible the issue is exacerbated by a unplugged hose somewhere. Your first mechanic had the intake apart to do the coils, he might have left the VFAD nipple unplugged. It's under the throttle body, out of sight for the unfamiliar. This would show up as positive fuel trims on a warm idle in your OBD data.

 

Thanks for fast replies.
@sonicsdaman well i forgot to do 3k rpm, i had the car for a year and always did it and it never flooded....just dumb me and bad day. RIP

Check Engine is P2270, i got rid of CAT when i bought the car (just gutted it since it melted), since then it always shows me the same code. The mechanic looked at it and said that the O2 sensor (lambda) wasn't burned and was working fine.

All stabilazed to sea level and 250 rpm. Yeah it's pretty bad but he says that until the car starts fast it's ok....

The car is original, i'm the third owner, i got all papaer of the first owner but none on the second but he had the car only for 1 year.... I loved this car, pretty clean inside and outside..... was pretty fast to start cold/hot. The problem was that I didn't check compression so let's say I went the crazy way.
After i got the car i changed plugs, radiator (since the car was a bit too hot and was leaking a little) and the thermostat, deleted CAT, changed clutch, and now changed coils, wires and plugs (again). In one year i got 15k km on it.

Yeah i looked at many threads, all differente, and mine is pretty special since it dies at iddle only after it got flooded. Before it almost never did it (only once on a hill), but it never had roguht idle or hunting idle until it got deflooded. I just hope if it's the engine it will go away, many people had the problem even after changing engine so i don't want to make the same mistake.

@CaymanRotary pretty much yeah.

@Loki dunno what he wants to do but he's sure it's not the engine..... the problem is that in Italy you got only 2 mechanics who are good (famous) with roatries, so i went to the one closer to me (didn't want to go 500 km with the car in this state, and to tow the car it costs 1000euro for 500km.... RIP

The compression test was done after I bought the car with my first mechanic, but he was pretty lazy and gave me only the mean number on first and second rotor which was 6 and 7 on 250 rpm nothing more.

Yeah it should have, i did 200 km on it after taking it away but nothing. I also did the 20 times on pedal but nothing. Yes I thought that the first mechanic forgot something, since it's strange that the car was fine one day and dies the next one.

Anyway thanks again for replies... as for what i will do is think if opening the engine will help or not, also I wanted to ask if I have to change the housing or not (even tho it's in prefect conditions), in some post i read that it's better to change it but never got why ?

 

The 3k trick doesn't do anything, it's a youtube myth.
I don't recommend rebuilding your own engine, get one that has already been rebuild by a professional and put it in. Given the compression numbers, I wouldn't put a lot of faith in the housings being reusable.
Not sure about Italy, but some of the US-based rebuilders will buy your used engine for parts.

 

It sounds to me like the fuel trims have not been reset. Do a search on that procedure.

 

Hi guys, in the end I went for a rebuild.

Turns out it was a side seal, half of it was missing. The other half destroyed the rotor since it couldn't come out. The housing and irons are fine.

 

Not too bad then. Just have to replace that rotor and new seals. Would recommend using new bearings on the other rotor in addition to the replacement rotor. Good idea to change them out since you have the engine apart.

 

Hello guys, so it's been almost a year so here's the udpate.
After rebuilding (done by a professional) the car doesn't die at idle anymore, but it started to have more startup issues (or maybe I'm just paranoid). I'll post videos so you can see:


Cold start lately (last 2 months):


And here we have a good cold start:


And I'll add a hot start, it's pretty good.


I did 3000km (1800+- miles) after the rebuild. He used Atkins apex seals but everything else was mazda. He also did a compression test after 1000km (600+- miles).

Front rotor kPa 736, 835, 719 in 250rpm
Rear rotor kPa 777, 719, 761 in 250rpm
He said that those numbers would go a bit up since the engine is new.

I talked with him about those starts but he said that it was the starter (the battery was changed with engine rebuild so it's new).
The doubt I have is that I saw many videos with bad starters but this doesn't feel like one.

 

Guess I missed your thread a year ago, but I was gonna say that the idle searching is either a sign of vacuum issues or low compression. Happened on my previous too tight tolerance rebuild sitting around 60-75psi@250rpm. I did notice a vacuum and idle improvement by getting new elbows for the vacuum lines on the intake, just before the throttle body. Plus those little ***** suck when they break.

If you haven't done an ignition upgrade yet, it would definitely help. New plugs always see a night and day difference improvement. Plugs can foul easily if they have been through a rebuild, I changed mine about 2000 miles after a rebuild. Personally I would recommend going with an LS coil kit if you plan to keep the car long term.

Another good buy is a new upgraded 2.7hp starter. If you happen to live near southern New Hampshire I have an extra sitting on a shelf.

The fuel pump is most likely fine if you have been able to go past 7-8krpm. Doubt it is fuel injector problems

You can check and clean the Crank position sensor, the ecu might have trouble getting a good reading.
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Generally cold starts are issues with ignition/charging/starting systems. Hot start issues is when the finger gets pointed at the engine.

Is this only ever on cold starts?
How frequent?

 

spark load test the ignition coils and spark plug wires first, then do a compression check if those check out.

120 psi is 827 kPa; if it doesn’t have at least that on all six faces from the start it likely never will, which is often a result of using out of spec used rotors and/or housings. Which is why I always recommend they be replaced.



.

 

Reusing the housings probably lead to the lower compression. Housings could be considered a "wear item" due to the loss of material and scratches that naturally occur when running this engine. Your compression is definitely better but after 1000 km, your numbers will only go down and not up. 7-8 bar is pretty low for a freshly built engine. That's not to say your engine can't or won't last a good long time however as your numbers are still well above Mazda minimum spec.

 

CaymanRotaryTeamRX8MincVinyl
Thanks guys, yeah I left old housing, iron and rotors, changed everything else. Coils, spark plugs and wires were changed with new ones with the rebuild.

The started is pretty old, like 2006 starter (since it's original) and it's upgraded, but I think I'll change it soon (just wanted to know if it was the starter or something else).

As for compression I just hope it will last me 50.000km (30.000+- miles), I do around 10.000 km so I hope it will last at least 5 years.

I will do a compression test again but after 10.000km so next year and will udpate the post. Cheers

 

I’m guessing you aren’t located in the USA then?

 

No, I'm from Italy.

 

So guys here's the update after a year...

the compression numbers are now at 556 585 528 and 490 457 554

completely different from what i hoped, i did 10.000km on it, premixed but nothing helped, solutions ?

 

Need to take the engine back out again unfortunately. Rebuilding does work but getting a complete new engine unit is a more permanent fix.

 

yeah

i wanted to see how much a rebuild would last, hoping for 40.000km at least, but i think it will do only 10.000 more and die completely...

3000euros wasted... next time will get a new engine and won't play around...

 

It would have lasted longer if you opted to go for new housings. Rebuilds are a good option as long as the engine isn't too far gone. At this point I agree that a new engine is the way forward so long as the car its attached to has no further issues and is in really good shape. Otherwise would be better to also buy another shell that doesnt have any issues. Otherwise, may be cheaper to just buy a better complete RX8.