low rmp off boost launch slight hesitation

J

japakos

Member +
Hello lads, I'm having an issue with my 4efte.
Only off boost and only when trying to take off a traffic light or a stop, the rpms from let's say 2000 drop to 1000 even when I floor the gas pedal and I experience massive hesitation. After a while the rpms go up and everything is fine. I have no boost leaks (checked), every sensor is replaced , vacuum lines are replaced (no leaks), fresh ct9 turbo repair, ported manifold (and all gaskets checked). I'm running a 4efte on a hyundai to be exact. But everything is in place as it supposed to be. The problem is only at that low rpm and only when trying to launch fast off a traffic light. If it's uphill it gets worst and I have to slip the clutch or raise a lot of rpm till I launch correctly. It's not a bit issue but it's annoying.
Also, new spark plugs, trd leads, cleaned throttle body etc etc. I have checked every single thing but I am getting this crap...
One more to mention is that when the car is cold and only cold, my afr is 11.5 on idle and off boost while cruising is 16-17 for a couple of mins till the engine warms up.
One last thing. When I get that bog/hesitation my afrs are 14.7. I even added 10 degrees on emanage to fix this , it got a bit better but not perfect. The timing is stock 10 deg , checked with a timing gun. No engine lights whatsoever.
The afrs are 14.7 idle/cruising, 11.5 when on boost all the way to 1 bar.
The car made 153hp @ 1 bar on stock ct9 with FMIC and ported manifold , trd leads and iridium spark plugs on emanage blue and walbro fuel pump
No fpr, no fcd
I'm attaching dyno graphs torque and hp





4efte ep82 ecu.
Any ideas?
 
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weeJohn

weeJohn

Lifer
Its a very long shot that one, but the problem sounds to be air related and its the only other thing I can think of in the system.
 
J

japakos

Member +
Shouldn't I have a check engine light if that was the case?
It sounds really weird problem, the whole thing actually.It doesn't want to go off the traffic light it kinda bogs
To be as much accurate as I can. Let's say I want to go out of my parking in the morning. The ramp is 15deg uphill, I try to get out on reverse and if I floor the gas I bog down and go in again :). I have to slip the clutch in order to get out.
 
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J

japakos

Member +
spark plugs are new, and plug cords too. No oil anywhere double checked. It does this crap from day 1 of conversion. It drives fine no problems whatsoever. It doesn't want to take off without bogging/stalling. Ok another one, if I have 1200rpm on 1st gear and I floor it, it does the same thing. It just needs its time to rev for a couple of 1000 rpm. 14.7 on wideband there.. even +10 +20 degrees don't make any difference. maybe a little
 
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G

gorganl2000

Lifer
you have a fair bit of timing advance on the emanage in those low range cells
did you try putting the timing at 0 degrees on the EMB in those cells?

on 2 starlets i observed with EMU, it seems the cars liked being rich low down (idle until warm) and very low ignition advance
the ignition advance made them hesitate/judder when the accelerator was pressed---------usually until the car got to operating temperature
 
J

japakos

Member +
Yes the timing was 0 degress on the EMB in low rpm off boost. Didn't make a lot of difference when I put +10 there but made a bit. The car , until warm it's pig rich 10.8-11.5. When it gets warm its steady 14.7 (but I had to take -10% fuel to achieve that), anyway do you think I might add as much timing as I can in the low rpm cells? This issue I have is a bit better when the car warms up but it's still there and it's really annoying. By adding 10 degrees of timing made it a bit better but .. still annoying
 
J25GTi

J25GTi

Lifer
Did the engine run okay in the starlet before you made the conversion?

If it did then there is an error with the conversion. rather than the engine to my mind?

As you sure you have everything plugged in where it needs to be? Did you use the starlet loom, or was it custom made or spliced etc?
 
J

japakos

Member +
The engine run totally fine before I guess but I don't know for sure as it was off a jdm half cut. I blew up an engine and tried another one and does the same thing. So no engine problems. I'm suspecting the ecu though...
The wiring was intact and the only wires that were spliced was some instrument cluster wires and something like reverse etc etc. No the wiring is 100%. I used the starlet loom ecu to engine.
 
weeJohn

weeJohn

Lifer
Thats interesting with the plug gaps, maybe trying a new rotor arm, dizzy cap and even ignitor may help. It would be worth checking the alternator is working ok at low revs also.
 
J

japakos

Member +
OK, so a weird thing just happened. I went down and measure resistance etc. everything is ok. I hooked up the emanage to play with and here is the problem.
When I start up the car - cold, the emanage shows 650000 rpm and goes up and down.. when the car gets warm I have correct readings!
I then turn off the car. After 5 mins I start the car again and whoa! here it goes again 650000rpm and playing.. after 2-3 mins it clears out. Readings on wideband though are correct. When the rpm readings are crap I have misfire.. like everywhere. When rpm readings clear out everything is fine.!
 
E

elison

Member +
what range of plugs are you using?? Iridium plugs are pre gapped. I always ran them out of the box and never had a problem. Its seems you could also have a wiring problem. Double check your tps. It could be vital.
 
weeJohn

weeJohn

Lifer
RPm readings come from the distributor, inside it there are 2 sensors. Check your connections on the 5 pin plug on the dizzy. Might be worth checking the ignitor long plug connections also.
 
J

japakos

Member +
Rpm signal on emanage was loose. Fixed it but the car acts the same. I mean I now have a steady rpm reading but the car when is cold it misfires till it warms up. If I turn off an then on it jerks for a couple o minutes then its ok. Hesitation off launch is still there nevertheless
 
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