B16A Idle and Rev Problem

[hisoka]

Hey guys, just need a hand with my civic, its an eg4 with a JDM B16A engine conversion. 2 Months ago is when this problem began, and its very weird since I've gone through almost completely every system related to the problem.

Problem 1:

1a) On cold start (mornings especially) it takes at least more than 20 times to turn the engine over. (This involves turning the ignition to "ON" and waiting for the main relay to click 2 times and hearing the fuel pump priming).

b) Turning the ignition to "START". (starter motor spins, engine turns over and then dies straight after).

NOTE: As stated above this process is repeated more than 20 times to at least get the engine warm enough for it to idle on its own.

c) Once the engine is close to idling on its own, the car will idle very roughly and sound like its going to die (average rpm at this stage is less than 500rpm).

d) After all that to and repeatedly turning the ignition a little bit more the engine will turn over and will idle normally, (average idle 1000rpm or higher).

This process takes at least 20-30 minutes to get engine started.

Problem 2

NOTE: Only when the engine is idling normally

2a) I open the throttle and it revs but drops at about 3000rpm. (Sounds like its choking, and if i hold the throttle long enough the engine slowly starts to die.)

b) Once i release the throttle the idle will jump straight back up and idle normally again.

Here is a list of the systems and the things I' ve gone through to get this to start.

Fuel System

2a) Fuel Pump:
Swapped the original fuel pump with a brand new generic brand (direct replacement for oem), also have another OEM pump bought from wreckers. (All of them prime).

b) Fuel Filter
Bought new fuel filter

c) Injectors:
Cleaned the original ones and bought another set from wreckers

d) Fuel Rail:
Cleaned original and bought another from wreckers.

Sensors:

a) TPS Sensor:
Have Changed TPS with a working one. (Was not parted out from throttle body, directly swapped throttle body).
*HAS GOTTEN RID OF CODE 5

b) MAP Sensor:
Have changed MAP sensor with a working one. (Was not parted out from throttle body, directly swapped throttle body). I also have about 3 others I've got from the wreckers.
*HAS GOTTEN RID OF CODE 7

c) ECT Sensor:
Have changed ECT sensor. Have about 5 of these and bought a brand new OEM from honda.
*CODE 6 STILL REMAINS, RESETTED THE ECU MULTIPLE TIMES AFTER SWAPPING THE ECT SENSORS AND STILL THE FAULT COMES UP.

Electrical:

a) Distributor:
Bought a new one, since the wires on the original were fried.
*TIMING HAS BEEN READJUSTED AFTER INSTALLING NEW DISTRIBUTOR

b) Ecu:
Bought a reconditioned OBD1 P29 ecu with B16A Map installed from ECU-MAN. Original OBD1 P30 ECU had a capacitor leak onto the main board and fried it.

c) Main Relay:
Have changed this multiple times since ive got 2 of these.

Engine:

a) Spark Plugs:
Brand New, did a service two days before it died. Have checked to see carbon build up and have cleaned the points multiple times.

b) Engine Oil:
As stated had a service, oil is still fresh and topped up.

c) Coolant:
Has been topped up, but NOT been flushed for air bubbles since I broken the system by swapping the ECT Sensor.

These are the things i can think of at the moment that I've done. I'll post more soon as I can remember. Anyway any help would be great please, as I'm in need of my car soon, and it sucks paying for rego and not even being able to use it.

[Bludger]

compression test it, possible BHG.

[dorikin]

So what are the current CEL codes you have? only Code 6 ECT? If you replaced it with a new ECT and its still showing the code then there's a wiring or ECU problem.

Also if you can't rev above 3000rpm your ECU is in LIMP mode

[hisoka]

Only .code 6 remains, I am assuming its a wiring problem but dont know where to start to troubleshoot the problem. And LIMP mode? Sorry mate im a but new to the Honda car scene. A bit more information? Cheers.

[dorikin]

Limp mode is the ECU's Back-up function. When an abnormality occurs in the ECU itself, the injectors are controlled by a back-up circuit independent of the system in order to permit minimal driving. In simple terms, the ECU is in safety mode.

First things first you need to clear the CEL Code 6. To troubleshoot the ECT sensor you need to do a Continuity test, Voltage test and Resistance test. Find a service manual and follow the steps or have a look through the DIY archive; ECU MAN has some articles on troubleshooting CEL codes.

[ECU-MAN]

You should start at this link below

http://www.ozhonda.com/forum/showthread.php?67113-DIY-PGMFI-Diagnostics-Codes

for example click on the ECT Hyperlink for code 6, it will teake you here

http://www.ozhonda.com/forum/showthread.php?67460-DIY-PGMFI-Diagnostics-Code-6-ECT

read that thread. Perform the continuity test from the ECT Connectors back to the ECU.

Ensure you have the TPS connector Connected to TPS and not the MAP and vice versa.
You can also perform continuity test from the TPS and MAP back to the ECU to confirm you have the sensors connected correctly.

With PGMFI Issue for engine transplants, continuity testing your sensors is really the first step. This ensures you have wires and connectors in the correct place for the ECU to function correctly. If you do not have a Digital Multi Meter ( DMM ) get one. learn how to use it.

when you have confirmed your wiring is OK to the sensors from the ECU, use the meter to measure power voltages to the ECU's main power feeds and check its grounds.


If you suspect your ECU is faulty, I can check this for you free of charge if you cover shipping costs. ECT problems can cause weird idling issues and will leave the ECU in Limp Mode.

[hisoka]

Thanks guys, will begin to troubleshoot the problem with your help, I'll update again soon if I cannot fix the problem.