bigger FMIC= hesitation under WOT

[Dew511]

I guess might apply to any vehicle but a 1JZ is what I have so:

I just got a huge FMIC installed. I can definately feel the difference. It pulls way harder but under WOT after about 4.5k rpms, it will hesitate once or twice on its way up to redline. I dont know what it is. I wanna say its fuel cut but again, Im not sure. The FMIC is the only thing to change. At this very moment, I pulled the EFI fuse in an attempt to reset the ECU. Hoping that now it will relearn with the addition of the big ol' IC. Lemme know what u guys think or rather... KNOW!

 

[SupraRacer]

Define: "Huge"

A larger IC can cause greater lag, its all about volumetric efficiency

 

[lagged]

have an EGT gauge? how old is your fuel pump? have you read your plugs lately?

 

[zoonwen]

how much are you boosting when it dose that ?

 

[Dew511]

SupraRacer: Huge= about 24x12x3 with 3" inlets and outlets... well maybe its not that huge! Im pretty sure its a 24" core.

lagged: I dont have an EGT gauge. Im guessin its the old pump and I havent checked on my plugs since I got the car. Which was about 3 months ago. The guy I bought it from assured me that the plugs were new and were gapped correctly. It wouldnt hurt to check em tho.

zoonwen: Im boostin at or about 12 when this happens. Whenever Im WOT. I havent upped the boost or anything.

 

[jbsupra89t]

Check your plugs, mine were fouled and it made the car a pain in the ass to boost. Breaking up and whatnot, changed 'em out, flawless (and also leaned it out a little). Check your fuel filter as well. Good luck.

-J

 

[Dew511]

Which plugs did u change them to? What was the gap and all that?

 

[jbsupra89t]

NGK 6097s, .028 gap. I am also running a bigger single vs. the twins, but IIRC searching on SF when I was in your position yielded me the same results even with guys on twins

-J

 

[Dew511]

This morning I drove the car again. I actually watched the boost gauge this time instead of the road! :naughty: Its boostin way past stock. Its builds boost very fast to the normal 12lbs. but then if I keep on it, it will creep to 13,14+. I havent hit the "hesitation" again since I've been watchin the gauge. When I see it get that high (14lbs.) I just let off. What is the boost cut set at for the factory 1jz motor? But anyways, this leads me to believe its just hitting boost cut. Am I wrong with thinking that. If not, whats the remedy for that? Boost controller maybe?!? O... also, I checked my codes and 34 came up... which is listed as turbocharger pressure.

And is boost cut and fuel cut essentially the same thing?

 

[drunk_medic]

Sounds like a leak in your hose going to your wastegate actuator, or a faulty wastegate causing you to overboost.

 

[supraturbo1987]

i have NGK 6097's but when I gapped them at .028, I fouled them out...not enough spark to burn all of the fuel. So, I gapped them at .040 and they have been perfect.

Trev