Guy at work gave me a P28 auto ECU. I've been wanting to fool around with it on my 96 civic d16y8 for a while. Converted the ECU to manual, bought a chip, soldered it in, boom. Works great, love the launch control blah blah blah. Turn the car off go to sleep. Wake up to start car, no fuel prime.

Went back to the guy who gave me the ECU he said he had it checked out once before guy said it had a bad cap. Googled it and sure enough bad caps. There are 8 of them. Replaced all 8 with high quality Panasonic caps (why not it was $8 for all). Put the ecu back in boom back to perfection. Well guess what happened this morning. No fuel pump prime.

Sat in the car for a bit messing with the ignition switch. Let it sit in the ON position for about 5 minutes boom fuel pump primed. OK turned the key off, turned it back on 30ish second delay fuel pump prime. F it Ill go google this. Got nothing.

Anyone have any ideas? Is there a transistor or anything else inside the ECU that could screw with fuel prime? Don't tell me to check for loose wires or any dumb s*** I'm not stupid. My p2p ecu is laying right next to the p28 and my p2p work just fine. Don't tell me to just use my p2p cuz I'm tired of the CEL for my cat and it runs so much better on the p28.

As I said I've replaced all the caps. Went back and checked my solder job on both the caps and the chip kit using a multimeter. I did check the wiring mainly at the odb1-2 adapter. Out of ideas and google failed me. Anyone ever just bypassed the fuel pump? I could just run a separate relay off the ignition shouldn't hurt anything. Would rather fix the ecu tho.

 

Is fuse 13 or 44 blown?

No spark also?

 

Fuses 13 and 44 are good. Spark on all 4.

 

Gonna try something even though its getting late here. The ecu works when I bring it from inside my warm house and plug it in. But when it sits in my car overnight (its getting down to the 40s at night now) it doesnt work. So it's not working right now gonna warm it up for a bit in the house and see what happens.

 

Unplug ECU connector A. Turn key to ON(II). Ground the wire at pin A7 or A8. Does the pump run?

 

Kind of redundant to do this but I did just to appease you I guess..not sure why.
My main relay is fine if that's what you were getting at. Applying ground to the negative side of the coil in the fuel pump side of the main relay....As I stated before I know my problem is in my ECU. I also slightly confirmed that temperature may be a problem. After doing your test I plugged in my "warm" ecu fuel pump primes. Your "test" did help a little. If i do decide to bypass the fuel pump Ill just add a switch to give (-) to that pin.

Any other thoughts on what's wrong in the ecu. I could take it to a guy that lives near me and I know he could repair it, I just don't want to pay him $50 for the $1.00 component he's probably going to replace.

 

The test bypasses the ECU, not the fuel pump.

 

You know what I mean.

 

I have no idea what you mean. What makes you think the ECU is bad?

 

Okay. When I did your test and grounded pin A7 the fuel pump primed. Normally that ground is supplied by the ECU when the key is in the ON and START position. The ECU is not doing that. So you tell me why my ECU is not bad. Because sometimes it works as it just did when I brought the ECU from inside my house. Sometimes it doesn't when the ECU sit in the car in the cold.

 

Do you have problems answering simple questions? You made the claim the ECU is bad. I'm simply asking what definitive evidence you have?

 

No problems and no I don't have definitive evidence, other than it only works when it wants to. Do you have any ideas on what else it could be?

 

Run the car on the P2P for a week. If the problem doesn't happen, then you've narrowed the issue to the ECU or the OBD2-->OBD1 conversion harness.

 

Yeah I'll give it a shot. The car has been running the p2p for probably all its life. That'll also give me time to triple check the obd2-1 adapter and time for me to test the o2 sensor fooler I've been working on. CEL are so annoying. And god forbid the poor people in the chinese sweatshop mis-pinned a wire on that harness.

 

Been running fine on my p2p for weeks. must be the p28. As I asked before does anyone know exactly what components control fuel in the ecu? Been researching quite a bit and have found some transistors that go bad but mine aren't.