Hitting Brick Wall at 5000 – 5500 rpm

[synco357]

Hello members,
I was wondering if anyone could help me out with this intermittent problem I’m having. I was at the dyno this evening and every so often, I’ve been hitting a brick wall around 5000 – 5500 rpm.

My setup is:

JDM Aristo 2J Auto with Tom’s TEC - remapped ECU
OEM New coils and connectors, New IK22 Plugs gap .022
New HKS dli
SAFC 2
New Siemens 720cc injectors and resistor pack wired up
2- Bosch 044 External Pumps
Turbonetics T66 BB A/R .81, LOG manifold
Innovative 50mm Wastegate
Spearco intercooler
2 – HKS Racing Bypass valves

I’ve tried the stock ECU, disconnecting the DLI, Wiring the speed sensor straight and bypassing the cluster, installed new OEM coils and connectors.

Furthermore, I’ve installed a US spec shifter but the neutral safety and gear selector recognition switch is wired up…
Could this be my problem?

Any help is greatly appreciated as this is driving me crazy.

If you have experienced this problem please give me a call as I can explain verbally in greater detail. Any help is greatly appreciated as this is driving me crazy.


Thank,

Andre
561 716 2678


Video Link:
http://www.youtube.com/watch?v=kOwsn9Qt7ak&feature=channel_page

 

[Supra-Man18]

How much boost are you running.. and what does this "Re-Mapped Ecu" consist off specifically ?

 

[synco357]

How much boost are you running.. and what does this "Re-Mapped Ecu" consist off specifically ?

Re-map Tom`s ECU eliminates boost cut, speed cut and raises rev limiter. I would think fuel and timing curves have been altered as well.

The car made 437 @ 20 psi. Thereafter, we ran 2 more passes and it started to break up at 5500 rpm. So, we turn of the car and restart and it made a complete pass at 7200 rpm, decide to run again and 5500 brick wall persist.


Driving me crazy... any ideas?

 

[suprahero]

It sounds like you're hitting boost cut. If you turn the boost down just a bit does it make a clean run? Maybe it's blowing out the spark. It's hard to tell from the short pull. Good luck.

 

[synco357]

It sounds like you're hitting boost cut. If you turn the boost down just a bit does it make a clean run? Maybe it's blowing out the spark. It's hard to tell from the short pull. Good luck.

It would also do it intermitently at 10psi boost. I have a HKS Dli, plugs are gapped at .022

Do you think I need to gap them closer?

 

[new88sup4me]

hey, are you running a wideband O2 sensor?? whats it saying? what is your fuel pressure doing? Can you run it at 5500 Rpm (not climbing) and it run smooth?

 

[synco357]

hey, are you running a wideband O2 sensor?? whats it saying? what is your fuel pressure doing? Can you run it at 5500 Rpm (not climbing) and it run smooth?

Dyno Jet wideband saying 11.2, My Innovative Wideband is saying 10.9-11.0, Fuel pressure is 60-65 psi. @ 20psi load

If I I dry rev the car in park, it rev`s to 8000 rpm with no problem.

The neutral safety switch and gear position locator is wired in on the auto shifter... Could that be the problem?

 

[Supra-Man18]

It sounds like a boost cut to me...Did you notice any spikes in boost at all during the pull ?

 

[synco357]

It sounds like a boost cut to me...Did you notice any spikes in boost at all during the pull ?

I did 2 passes at 20 psi and they were clean as ever... 437 HP.

So, I don`t think boost cut is the cause as it would have cut way before I reached 20 psi... does this make sense???

 

[RacerXJ220]

Water temp sensor issue???

 

[synco357]

Water temp sensor issue???

my water temp was between 190 - 210.

Are you saying the water temp sensor could be the cause?

 

[synco357]

Any suggestions as to where to go from here!!

 

[alloyguitar]

We had a 1jz that wouldn't start because the coolant temp sensor wasn't plugged in, so it very well could be.

 

[SC300fivespd]

.022 gap? are you kidding me? why is it so frekkin small? never heard that what heat range are the plugs? id say a 7 or 8 heat range with a .8mm gap would be good and also make sure there are no air bubbles int he water system chech the temp probe. lets see what that does. it sounds like the spark is being blown out. mine id that..

 

[IJ.]

.022 gap? are you kidding me? why is it so frekkin small? never heard that what heat range are the plugs? id say a 7 or 8 heat range with a .8mm gap would be good and also make sure there are no air bubbles int he water system chech the temp probe. lets see what that does. it sounds like the spark is being blown out. mine id that..

You suspect spark blowout yet your advice is to go from 22 thou on the plugs to 31 thou?

contradictory

 

[a_sesshoumaru]

not trying to thread jack but i am having the same problem with my 7mgte, i changed coils, wires and plugs, what else could i try? i have this with 17 or 10 psi, always 5500rpm.

 

[IJ.]

not trying to thread jack but i am having the same problem with my 7mgte, i changed coils, wires and plugs, what else could i try? i have this with 17 or 10 psi, always 5500rpm.

5200 is usually torque peak and where cylinder pressures are at their highest hence the spark blowout, IF you have enough Octane and some way to adjust the timing map around that point you can dial in some more advance and that might get you over the blowout and remove the stumble, failing that you can try smaller plug gaps or upgrade the ignition system for a bigger zap.

 

[a_sesshoumaru]

5200 is usually torque peak and where cylinder pressures are at their highest hence the spark blowout, IF you have enough Octane and some way to adjust the timing map around that point you can dial in some more advance and that might get you over the blowout and remove the stumble, failing that you can try smaller plug gaps or upgrade the ignition system for a bigger zap.

Right now i am using new ngk grade 8 spark plugs gaped to 0.022" , why is this happening? i used to boost 23psi everyday with no issue at all. what should i gap my spark plugs at? is it the ecu failing?

 

[IJ.]

Tired coils, different ambient temps, many variables can cause this if you're close to the ragged edge tune wise (so many here are it's not funny)

I always go for a conservative tune for this reason.

 

[JPsToyota]

I'm thinking the original posters problem was the neutral safety on the Aristo ECU. It has a built in rev limit that only occasionally will work sometimes. Just wanted to say for shits and giggles, I guess.