1JZGTE dropping out.

[marvis]

Hi there,

I have a Auto (A340e) JZZ30 1JZGTE with the following relevant mods,

Custom dumps,
FMIC,
3" exhaust with no cat
070 external Fuel pump,
Bk7 plugs gapped at .7mm


I have changed the fuel filter, fuel pump and the coilpack plugs in the last month (Also the solenoids in the box). I can't check my Diag codes as it's in a MZ10 and it has no option on the dash..

The problem is if I go WOT from a stop or at a low speed it drops out, I thought this was boost cut so I installed a 2" restrictor in the exhaust to drop the boost down to 10PSI at the manifold. The boost dosn't spike at all, the power just drops and is really jerky, if you keep it at WOT it will usually keep doing it. I can be doing ~100 and go WOT and it has no problems.



My next thought would be to check the fuel pump voltage, TPS and then the fuel pressure at the fuel rail, or swap out the stock fuel regulator.


Would anyone have any other suggestions?

Thanks,
marvis.

[dnegative]

[youtube]http://www.youtube.com/watch?v=Lgr9CjG7pwU[/youtube]

Anything like that, that was WOT in 2nd gear from memory

[stealth]

I just had a very similar issue. turned out to be shot FPR. Does your pump sound like its straining? more noisy than normal?

[HAVABEER]

What computer is running it? Just the stock jzz30 one? Could be leaky caps in the ecu, also I think there's a way you can actually hook up a light to the ecu to give you error codes, google a how to on how to do it

[marvis]

Stock JZZ30 ECU. I'll open it up and sus it out if FPR and voltage are fine.

I just had a very similar issue. turned out to be shot FPR. Does your pump sound like its straining? more noisy than normal?

I'll try a new FPR! Sounds normal I guess, can't hear it over the exhaust when driving though.

[youtube]http://www.youtube.com/watch?v=Lgr9CjG7pwU[/youtube]

Anything like that, that was WOT in 2nd gear from memory

Nah, it full drops boost and is real harsh, picks up again for a second or so, drops again unless you hop off throttle.

Sometimes it does it, other times its ok. It mostly does it.

[dumbass]

Have u had a proper boost gauge on it
One u sort of know is accurate

It does sound like boost cut

I would also fit fuel pressure gauge and road test

Has it done it since the engine was fitted
Find the w wire and hook a test light to it
Then bridge out the terminals in diag plug and check codes
Or wire up the proper diagnostic plug and fit a scanner to it

I got a 1j to look at tomorrow with no kick down
Normal problem is some idiot has wired it up and said there u go to customer
So typically customer has to fork out Moore money to get it done right

[marvis]

Wouldn't be hitting boost cut though? It doesn't have a boost T so there isn't a reason for it to spike 4-5 PSI?

It was working fine a month ago, I had it off the road for a few days doing the box solenoids and coilpack plugs as it was breaking down, fix that and it started doing this.

Thanks for the suggestions, I'll try to sort out a diag light!

[stealth]

Yeah it does sound like boost cut, but if he can go WOT at higher speeds he would be reading more boost in higher gears if anything. The problem would be worse at high speed if it was boost cut i reckon.
My problem started with a noisy fuel pump, then I had fuel starvation at anything past 3/4 throttle. sometimes worse, gradually got to a point where I could drive the car for a km then it would stall. Turns out my FPR is either blocked or jammed shut, it is a complete restriction even with full vacuum, it just doesn't flow anything at all.

Wouldn't be TPS issues, it only has settings for cruise and idle anyway.

explain your fuel system, what have you modified? Do you have a lift pump/surge tank for your external pump?

[marvis]

It's stock, z1x soarer have an external pump stock. I just fitted a 070 pump as I thought the previous (stock) fuel pump was the issue.

[dumbass]

sometimes boost cut can be hit at mid revs but high load
just as engine starts coming on song u can hit boost cut especially in 1st or 2nd gear

hitting boost cut in 4th or 5th can be a little bit harder since u r going much faster and load on engine is not as great

[marvis]

What would cause this?

[George]

So typically customer has to fork out Moore money to get it done right

Being tight on a budget and using your head just to eat and drink introduces you into the wide world of missing, hunting, stalling, boost cutting, kicking and whatever else. Money talks or how do they call it

Specifically relates to this being completely ignored

light to the ecu to give you error codes

[stealth]

What would cause this?

Im still trying to figure out my issue too. Turns out my FPR was okay, cracks open at 32 psi like it should

So I'm stumped now...

Check the suction side of the pump, there could be a hose sucking closed?

Hooking up a fuel pressure gauge will help you diagnose this too...

[wilbo666]

Wire up a check engine light mate!

While there might not be provision in the dash, in the mean time you can put it somewhere else to help in your de-bugging!


I have a feeling that JZZ30 might be special and not have a 'W' pin in the engine mounted diag box so you will need to connect a light to this (the engine ECU, W'W pin) near the engine ECU, or the body loom plug coming from the engine loom. Let us know if you don't know how to wire it up.

Cheers
Wilbo

[japlish]

Yup I had to tap into the loom near the ecu on my jzx90 ecu in my cressy to get the diagnostic light show happening, not too hard as long as your not colour blind!

P.s did you get this off a guy named dave?