Honda D Series Forum banner

Turbo build Rough idle when warmed.

5K views 26 replies 15 participants last post by  rider5000 
#1 ·
Ok so here it goes:

D16z6
Vitara pistons (75.5mm)
eagle h beam rods
Acl bearings
eagle crank
Rc 550 injectors
stock fuel regulator
XTD 8lb flywheel
XTD 4 puck clutch
GT3076 turbo on 10lbs
Unorthodox racing light weight crank pulley
cometic head gasket
stock oil pump
Stage 1 crower cam
AEM adjustable cam gear
oem replacement valves/ valve spring ETC.


Now i have built the block. Plastigauged everything clearances are good. the head was built at a shop. Valve lash and everything seems good. It is timed correctly and has good spark in each cylinder.
The car runs fine and doesnt really seem like it loses power. What it does is when it warms up it starts to idle lower and lower and lower the warmer it gets. We had someone tune it and according to that guy it is not running rich.. which i believe it is and that his tuning equipment is out of date. Anyways looking aside that and believing what he says i have run out of ideas. Changed the spark plugs, wires, thermo valve looks clean, iacv works fine. new map sensor.. I just dont know. It runs perfect when its cold but doesnt like when its warm.. So my initial thought is that it is still running rich. Maybe i could get some opinions before i cough up $400 to throw it on the dyno.. please please please.

If there is another post about this i am sorry i just could not find it any where on here.
 
See less See more
#4 · (Edited)
Running lean.

Try turning off all electrical to enrichen mixture until you can fix your tune.

My car does the exact same thing. I can change from 12:1 idle to 16:1 with my blower motor on vs off with the headlights on.

If you don't have a wideband, get one you damn noob. I recommend the MTX-L.

The lean condition is only at idle not load. Dont Worry
 
#7 ·
I actually believe injector battery offsets can compensate to a certain degree, regardless of correction factor. I modified my table as much as I could to get accurate AFR's at idle with headlights and such, however, at operating temperature with fan AND headlights, my compensation seemed not to have enough affect.

I then went, and reduced IACV correction, increased throttle body bypass (screw), and retuned battery offset tables with success. Good luck!
 
#8 · (Edited)
I had the same prob when I turn on my regular head light I get low rpm that bounce ten turn on high beams it goes away or if theirs no head lights on at all it idles so ima jus tune again to correct it.
 
#11 ·
I had the same prob/ a roughness feel in the motor turned out had to shim the valve springs but I went with sutertech springs, delta 272.2 my seat pressure needed to be 100lbs stated by delta supertech springs were 60lbs, also I had to gap my plugs to .028 and my engine became happy :)
 
#22 ·
True after the motor is built driven then do another valve lash. I gapped my plugs .028 that stopped my shuttering at high rpm wot. But check plug gap and valve lash if it doesn't help get that re tune like every one is saying.
 
#25 ·
ouch...

hopefully you didnt fry your injector driver (usually happens fast).

That pesky HIC board is a %$&&%$ to remove without a proper station and a lot of effort.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top