bambbrose

This will be long but I want to be detailed as possible. Please read if you have time and offer any input. I've been trying to figure this out for weeks.

Car Details:
Car is 97 civic dx hatch.

Engine is 94 JDM H22A

Engine harness is the 97 DX harness

Using Rywire obd2a to obd1 conversion harness

My ECU is a chipped p75 converted to p72, but I've also tried virgin p28 (which is verified to start and run h22 by my other thread), virgin p06, virgin p75, and known BAD P13.
I still have all five ECU's at my disposal for testing.

Symptoms:

We have two different scenarios

SCENARIO 1:

Using my known fried p13 ecu, or using my chipped ecu with a bad bin burned to the chip.

The car is in limp mode. While in limp mode the car will crank, start, and run. It runs like *** as to be expected in limp mode. Has solid CEL, which will not turn off when jumpered to check it. It does have the fuel pump prime for 2 seconds like it should. Idles like its about to die. Rev limit is 3000 rpm.

SCENARIO 2:

Using my ecu, or the virgin p28, or the virgin p75.

Crank but no start.
No check engine lights. When jumpered it is a solid CEL like it should be.
Fuel pump is priming for 2 seconds like it should.
Occasionally it will sputter as if it wants to start but never does. It sputters typically right after running it when in limp mode as if extra fuel is left over in the cylinder.

What I've done as far as wiring:
all wiring is done properly with solder and heatshrink. I've done multiple swaps and never had wiring issues yet

-Converted to obd1 distributor plugs, verified wiring with two diagrams located on H-T.
-Converted to obd1 alternator plug using diagram on H-T.
-Added knock sensor wire to D6 obd2a-->D3 obd1
-Added Vtec solenoid wire to A8 obd2a-->A4 obd1
-Added Vtec oil pres wire to C15 obd2a-->D6 obd1
-Added Vtec oil pres ground to thermostat ground
-Did IACV fix, moved IACV from A14 to A12, & removed A13 pin (orange wire), swapped IACV plug
-Installed IAB wire to A26 obd2a-->A17 obd1, and IAB power to A11 obd2a (ignition power)
-Installed oem honda resistor box following hondatas diagram.
-Installed EGR wiring according to the H22 EG/EK FAQ thread on H-T.

Things I've tried so far

-I've checked spark. I have good spark on all four plugs.
-I have fuel at the fuel rail.
-I have 12v with key on at all four injector wires. It also pulses when I crank as the ECU grounds them out.
-I have verified that I have peak/hold injectors via Ohm testing. They are obd1 injectors for h22a I am told. I have not verified that they are 100% prelude vtec injectors, as they could perhaps be h23 injectors.
-I have double and tripple checked my wiring. I have went as far as Ohm testing each individual wire to verify continuity. I have torn the entire harness apart to make certain that all the wires are going to the correct location.
-Obviously I have tried all of my different available ECUs as well to verify that it is not an ECU issue.
-I have checked actual mechanical timing with the cam gears and flywheel slot, as well as looking down the #1 cyl to verify TDC.
-I also check the Ohms of the coil and igniter and they are good as well.
-I have also checked the entire Obd conversion harness and it is correct according to ffsquad's diagrams.
-Trans ground, head ground, and thermo ground are all good grounds.


Does anybody have any insight? I have checked every last thing I can think of. Maybe there is something else it could be that I'm unaware of? I've never swapped an obd2a car before, only obd1 stuff so maybe it's something simple I was unaware of?

I'm baffled how it can run in limp mode but will not run out of limp mode.

Please please give any input, simple or complex.

Thanks for everything guys. I need to get this ---- going for AutoX later this month

bambbrose

I've triple checked it all already lol.

Its actually on the car without any loom right now so I can check it all as I get new ideas. Also all plugs have had their sensor name written on them and verified via Ohm meter to ECU pin to make sure they are the right plugs aka no mixed map and tps plugs etc.

SpeedyJAY

My guess is you are maybe trouble shooting 2 things at once? The limp mode thing throws me for a loop...the solid ECU means the ECU is either fucked, or power in/power out is fucked. If either one of those was messed up your car wouldnt start at all (well maybe if it was shorted ECU). Either way there is a wiring issue if the ECU is solid and will not allow you to check the code.

The other thing that I think of is your timing, did you set it? (you probably didnt if you couldnt get it to idle up a bit) Try playing with the distro timing a bit at a time and see if you get it to run better, or to a point at which you can get a light on it.

Do you have your OEM honda wiring diagrams ? Trace and verify every ignition wire at a time using your Manual's diagram. The sources you've listed seem reputable, but I dont trust anyone but myself when it comes to wiring.

Just start from the ECU testing continutity to the fuse, mark out each good wire with some colored tape to eliminate each connection from the equation. Then move on from the fuse to the sensors/distro/fuel pump/grounds....the key is being extremely systematic at eliminating as many wires as possible from the equation.


Ive played this game too...more often then not it always turns out to be something retarded

bambbrose

thanks for the advice. I feel like I'm running in circles on this damn thing. I'll start from scratch tomorrow morning and see if I get anywhere.

One thing I have just noticed, during scenario 2, using my good ecu, if I unplug random sensors before trying to start it it still wont start, but it never throws a code for any of them.

Can someone do me a huge favor and go outside, unplug a sensor, and then just turn your key to the ON position without starting the car, and then let me know if it shows a cel for that sensor?

I think map and tps are the main two that would perhaps cause a cel, but others might as well.

Thanks so far. I hope I can get this bitch running

bambbrose

I'm getting conflicting information on whether or not it will show the CEL when a sensor is unplugged.

Some people are telling me that it will, but others are saying that it will not unless the engine actually starts up and takes a reading. Thats why I want someone to verify on their car for sure.

bambbrose

I'm fairly certain that because of the way it starts in limp mode that can eliminate some possibilities but which ones I am unsure of.

Here are some videos.

First video is scenario 1, bad ecu in limp mode startup

http://www.youtube.com/watch?v=tGnS3evrGjU


As you can see it starts up and runs fine, with a slight miss at idle and 3000 rpm fuel cut. Once warmed up it will occasionally stall and will idle extremely low, missing often, and running worse. That annoying whine is just my timing belt being too tight. Its amplified by the video for some reason

Second video, scenario 2, good ecu, no CEL

http://www.youtube.com/watch?v=LBX_dmUgkkM

As you can see in this one, the engine cranks and occasionally sputters. I get no CEL at all regardless if I plug a sensor in or not. I've also tried unplugging random sensors and trying to start it with no luck at all.


Any new ideas?

here is my firing order



here are my injector wires, 4 is yellow, 3 is light blue, 2 is red, and 1 is brown like they should be. They also ohm test out to the correct locations at the ecu. The other wires all individually go to the resistor box, and then the resistor box ties into 12v ignition.

Guy-Fast

confliciting info if a sensor is unplugged it will throw a code




what do you think it will do if you unplug it work?



no it will throw a code



unplug the coolant temp sensor easiest to reach and watch code 6 pop up even before you start the car





but yes thats confliciting information that is correct




I only have 100+swaps under my belt that all ran tiits passed smog etc etc etc




but yes conflicting

Guy-Fast

oh and for the codes to show you need to click over to 2 aux so the car actually has power etc