I working with a GSR engine with GT35r in a 92 civic. Tuned by ill garage on ECtune with a P75 converted P28.

The following resistors have been removed from the ecu:
RP17, J4, R90, C71, J12.

Under 4000RPM the engine runs well, although at idle only, it's a bit rich most of the time at about 10.5 AFR. Often times, once in the 4500-5500RM is where my AFR's will suddenly drop to 9.9 and the car will fall on its face/cut out. Occasionally, I will be able to make it to 6500RPM where the engine will hold a steady rev and have an AFR of 9.1.

Now to add to that, if one of the above situations doesn't occur, what does happen is *** my RPM's rise above 4500 and boost increases the AFR will steadily rise and once it hits about 14 AFR I will get out of the throttle for sake of avoiding detonation.

I've been able to affect these situations above by adjusting fuel pressure and removing/installing the vacuum line.

Should I be using the vacuum line on a boosted setup?
What should base fuel pressure be?

MAP sensor only has 4.6V reference coming from the ECU (tested at ECU).
Coolant temp sensor has 5V ref and proper resistance across sensor.
IAT sensor is functioning properly.
I have tried 3 new chips from ILL garage.
I have swapped my chip into a P28 and got a solid CEL and car wouldn't start.
I had somewhat similar issues last year when I was on Chrome and I my car would intermitently run at 9.9AFR all the time.

Any ideas as to what could be causing these running issues, I am suspecting a wiring gremlin or ECU issue. These problems did not arise on the dyno while the tuners ECU was being used.



Thanks,

 

my guess is ecu but when you swapped your chip into that p28 was the ecu a known good one?
Try putting your chip back on the tuners ECU and see how it reacts.

Base fuel pressure and whatnot should be at the same level they tuned it.

 

The ECU I swapped with was a known good one as it had been used in three other cars for testing purposes. I am about 2.5hrs from the shop that tuned it and my work schedule does not work well with the hours of the shop.

I know this is bad on my part but while tuning, we were not able to read fuel pressure. To make things worse, after I got home I noticed that the vacuum line for the FPR was off and I came to the conclusion that it most likely came off the back of the IM while doing a pull since it was not as secure as it should have been. What I'm saying is I don't know exactly when the line came off during the tuning process.

 

bump

 

Try using that p28 again, and when the cel turns on, jump the blue clip on the ecu harness for diagnostics, it will make the CEL blink a certain amount of times and you can check the code bellow. Worth a shot. How does it behave when you raise/lower the fuel pressure?
short blink= 1
long blink= 10
Example:long blink long blink short blink= code 21
0-------ecu
1-------oxygen sensor
3,5-----map
4--------crank sensor
6-------coolant temperature (tw sensor)
7-------throttle angle
8-------tdc position (tdc sensor)
9-------#1 cylinder position (cyl sensor)
10------intake ait temp. (ta sensor)
12------egr
13------atmospheric pressure (pa sensor)
14------electronic air control (eacv)
15------ignition output signal
16------fuel injector
17------veihcle speed sensor
19------a/t lock up control solenoid valve a/b
20------electric load dectector (eld)
21------spool solenoid valve
22------valve timing oil pressure switch
41------oxygen sensor heater
43------fuel supply system (except D15Z1 engine)
48------laf sensor (D15Z1 engine)

 

I resolved my problem. I just don't know the exact cause but I ended up installing a junkyard engine harness from a D16 and the problems is gone.

 

Good thinking on the harness swap

 

Thanks

 

Ive created a new problem though. My vss is inop and I am forced to run a chip with no 2 step. I just got to figure the wiring out.

 

VSS wiring is easy. 3 wires, power, ground, reference. I believe the reference splits and goes to the ECU and to the cluster. I want to say Blue/White?

Been a little while since I've wired one, but all of this info is easily obtainable on this forum.

 

The wires on my 92 D series engine harness are:
yellow/blue (12v)
yellow/white (5v)
black. (ground)


the VSS connector was cut from the harness so i used an old one i had.
orange is connected to yellow/blue
black/yellow connected to yellow/white
black to black


i have no speedo reading AND my 2 step does not disengauge (has to be going 6mph) so i cant rev past 4500rpm.