Hondata

1996 integra
LSVTEC
DRAG turbo kit
STR fuel rail
6097 NGK
Nology wires
8.5:1
Sleeved
GSR head
GSR cams
1mm oversized valves
Skunk2 intake mani
RC750cc
Walbro 255
MSD ign. stuff
S200/GM 3 bar

Engine pulls only 10" at idle (650-750 rpm). Will not hold idle cold. Barely holds idle warm. Falls down to a stall coming down rev. Tried a different s200 unit and same problem. Tried a stock p28, same problem and throw a MAP code. When on S200 with stock injectors or 750cc's and according base map, same problem exists. Engine idle in columns 4-5-6 at idle. I had to adjust base ign timing at 950rpm (best idle poss). I set it at 14 btdc to be on the safer side. No vacuum leaks.

Back to the map sensor issue. The car is a 1996 ls, but the engine utilizes a 1995 wiring harness. Every signal checks out fine at the ecu. TP values are dead on.

Any ideas will be appreciated.

My first guess would be cam timing is off.

do a leakdown and compression test.

Jaker wrote:My first guess would be cam timing is off.

Already checked. Cam timing is right on the money. All timing points line up perfectly.

Thanks

Spunkster wrote:do a leakdown and compression test.

Already did this too. Compression is 165 straight across. Leak down is 2% across the board. This is a real PITA. My brain hurts. I think I tried almost everything so far.

I was trying to look deeper into the cam timing and realized the top end was really quiter than most B-series. Even with the stumbling/missing idle, they just seem really quite. I talked to the guy who built the engine and according to his memory of what he adjusted the valve lash to, it seems he may have too tight. He first said he set it around 2-4 thousanths. Would that cause this type of symptom? Valve train too tight? I'm gonna pull the valve cover tomorrow and readjust the lash just to be sure.

Anything else come to mind?

Thanks!

Make sure you don't have the TPS and MAP sensor plugs reversed.

ocd wrote:

Spunkster wrote: it seems he may have too tight. He first said he set it around 2-4 thousanths. Would that cause this type of symptom? Valve train too tight? I'm gonna pull the valve cover tomorrow and readjust the lash just to be sure.

Thanks!

Sure sounds to me like your valve lash is set too tight then. .002" is WAY too tight. Valves set too tight would mimic the same symptoms as wrong cam timing. I don't have the DOHC data in front of me, but the SOHC motors typically use .006-.007" for the intake, and .008-.009" for the exhaust. you can get away with a bit tighter than that, but I wouldn't go any tighter than .005" on the intake and .007" on the exhaust.

The DOHC motors use the same valve lash specs, I do mine to .007 all the way around for simplicity. :)