2jz gte Rev breaking up around 2.5-3k

[Sam Watson]

through id throw up my issue.

car breaks down around the 3k mark at idle and in every gear. including reverse.

how most times if its 100 accel it only breaks down for a second or 2 then continues to rev past it how ever at a massive decresses in power.
if its under 100% accel then it hits 3k rpm breaks down and continues to break down untill u lower the rpm down. or rev it 100% when it breaks down at lower throttle the car feels likes its going to stall it jolts that bad. when it hits the 3kish rpm mark.

2jz has been put into a silvia s13. with a to4z turbo on the side. 255lp walbro fuel pump. fuel reg. standard injectors. and ecu.

changed plugs No change at all..
swaped coil packs didnt make any difference.

i still have the standard FPD on the motor and inuse. not sure if this would cause any restriction to fuel or not.
bypassed the standard FPD and ran a line strain from the fuel pump to the fuel rail. ( didnt make any difference. )

FPR is running 40psi at idle rising rate.

. does any one have anyidea on what i can try to fix this ??

i have also swaped the map sensor. and ecu over with different ones. with no luck.

Car loom and computer are auto. how ever i haev converted this to manual. and then had it wired into a s13. could using a auto computer be causing this issue as its not getting a signal from the auto tranny that it should be ?

any help would be great.

motor is a jap motor 2jz-gte as well.

currently looking for a ecu to swap over to see if that fixes the problem and a ingnition module as well to borrow to see if either of them fixes this issues.

 

[Sam Watson]

also has the same miss fire and does the same thing wen free reving in neutral.

 

[te72]

The boots of your coil packs in good shape? What about the wiring on them? What are your plugs gapped at (should all be around the .028-.030 range)?

Lastly, Albert on here had a similar issue that had him pulling his hair out, turned out to be a kinked fuel line that got crushed while installing a new pump. Was causing fuel pressure issues, the end result being a 3k breakup...

 

[Sam Watson]

swaped coils but yes there good boots as well. and wires are fine. i had them replaced to make sure. plugs arnt gaped ill do that tomorrow and see if it makes a differemce. and i ran over the fuel lines in tank and outside and unfortanly i cant find a leak or a crush or bend or anything any other ideas ? and yes im ripping my hair out lol want it fixed already lol.

 

[Sam Watson]

ok so gapping the spark plugs didnt make a difference also did a compression test while i was doing it and made 184 accross the board... any other idea on what i may try.

Could a vaccum leak cause this issue by any chance >?

 

[te72]

Still good to have plugs gapped the same across the board. Nothing comes to my mind here, but I've mostly had a trouble free experience with my car, so unless it's a problem someone else has had that I've read about... Might ask if one of the forum mods would see fit to move this thread to the Other Engines section, seeing as how it's not in a Mk4...

 

[IBoughtASupra]

Have you checked for codes?

Tried a different igniter?

That 3,000 RPM issue is know in the JZ world. It is mainly caused by fuel issues but there are other things that can cause it as well. Have you checked your cam/crank sensors by OHMing them? Yes, that is not the best way but its just a start.

 

[Sam Watson]

what ohms readings should they be putting out cold ? or do you measure them hot ? fuel wise i have an walbro 255lpm intank pump cant image that fuel been an issue. have a rising rate fuel reg. as well. and couldnt find any kinks or sharp bends. or dints anywhere on the fuel lines.

 

[Sam Watson]

?

 

[3p141592654]

fuel dampener