1JZ MX83 breaking down in 2nd at 4500rpm FIXED

[Mr DOHC]

this is a big hit, i just took the guy from hardcore for a drive, he said it was the FCD, its booked in for this sat morn.

it pretty much sounds like a 2 step limiter, as it actually does limit the revs {by leaning out}

[chris davey]

Wilbo's done the zener diode and pot if you want to do that and sell your FCD

[Adam_Cressi]

sorry newb here FCD???

[Mr DOHC]

just played around with the FCD, its not doing it quite so badly now, but its hitting 25 pound

what could that be, leaking wastegate line

[wilbo666]

You can come round and try my coils if you want Phil,

Chris, the zener diode didn't work for me, havent got around to putting the other circuit on yet. And on an interesting note, my car now runs 13psi+ with no boost control / bleed now (it was 10-11psi when I first got the car on the road...). Strange I say.

Cheers
Wilbo

[Adam_Cressi]

just played around with the FCD, its not doing it quite so badly now, but its hitting 25 pound

what could that be, leaking wastegate line

Sorry guys whats a FCD?? And what does it do?

[Mr DOHC]

fuel cut defender, when 1J's hit 15psi it cuts the fuel, this stops that

[Mr DOHC]

what is this line, its the one that is sitting ontop of the intake, it was itting next to the head with nothing attached, but it had a hose clamp, i thought it may have been a wastegate line that weas bleeding off to atmosphere, so i blocked it, no change

[Mr DOHC]

fixed

heres the low down

in japan the car had a boost controller, but when it was sent over here, the boost controller was removed, but instead of re joining the lines like in the top left pic all he did was remove the 2 red lines and didnt even block off the t-peices, so the wastegates had no idea of the boost,

so for the last 2 years they have been shut, never opening, luckily the uber restrictive MX83 exhaust prevented overspeeding of the turbos to any more than 10psi. but now with the 3" mandrel system it was able to boost upto and over 25psi {i'm pretty sure i saw 27psi }

[Hibba]

Thats what raised my question before, when i first got my car one of the T-pices was melted causing the waste gates to to open and hit 25+psi

[1JZ.747]

just played around with the FCD, its not doing it quite so badly now, but its hitting 25 pound

what could that be, leaking wastegate line

you have a major issue, dont drive it hard till your sort that out mate


25 psi will kill factry turbs very quickly

[chris davey]

all fixed now then?

I think that is the most boost I have heard anyone running on ct12a's. I hope you didn't do it to often.

[thechuckster]

..it pretty much sounds like a 2 step limiter, as it actually does limit the revs {by leaning out}

you've since discovered that the problem is elsewhere - but leaning out fuel to limit the engine is bad and wrong - that last thing you want a boosted engine to see is not enough fuel.
If you want a progressive limiter, use something that drops random spark events - before killing spark all together.

[chris davey]

Don't most ecu's do that? I know the wolf 3d does.

[chris davey]

Just found this on microtech ecu rev limiters

Actually the stock setup is to cut ALL FUEL on one rotor on the limiter .. that being Primary and secondary on number 1 for example.
the REVCUT cuts all fuel completely unitl the engine gets 500rpm lower than the cut off rpm and then it brings al fuel back in.
When you have a total fuel cut you have NO combustion and NO LEAN OUT.
If however you have wired your secondaries incorrectly , it will cut 1/2 the fuel on each rotor and WILL lean out and you are right.. you will lose Apeax seals.
Best to never use the REVLIMITER function on a Rotary or staged setup. Just use REVCUT.
You can also order ECU's with ignition cut limiters from our factory.

If you have a Methanol car with large volumes of fuel in the manifold and in particular manifolds and Plenums with a lot of injectors sticking off teh top in a throttle body style arrangement rather than Multipoint, I certainly would suggest Ignition cut .
As fuel dregs can cause a milisecond lean out because of teh amount of methanol in the chamber.