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Discussion Starter #1
Hey guys. I just got done putting my D16z6 in my 98 civic. Purchased a P28 ecu off ebay just to start the car and check for vacuum/fuel/coolant leaks. Started the car fine and ran for the first two days but now won't prime the fuel pump. I know it's not the fuel pump because I took the p28 out and the conversion harness and hooked up my old Y7 computer and the pump kicked on. So I don't know if I got unlucky with a shit computer or if it was something I did..... some of the things I've done

-I soldered the vtec wires/wide band wire into the conversion harness wires to the correct pins because I could not get the pins to come out of the conversion harness for the life of me. I used 18 gauge wire.

-converted the iacv to the two plug connector and cut the orange wire and swapped the blue and black wire from a14 to a12. That went smoothly. Was able to get the factory connector open no problem on my original harness.

- Now here's where I wonder if I fucked something up. I took it upon myself to install a kill switch to my fuel pump as a theft deterrent. I bought a simple on/off switch from my auto parts store and cut the A7 wire and soldered in two wires going to my on/off switch which basically cut the power to the A7 wire when in the off position. Worked fine for a day or 2 and then started giving me problems.

Did splicing into the A7 wire and adding a switch mess up my ecu? I know you guys can't know for sure but I'm just terrified of putting in my p28 with hondata s300 and frying that ecu as well cause of something stupid.

I read something about switching an evap purge and iat connectors can cause the Q31 capacitor to leak but I highly doubt I fucked up that up. I don't even have an evap purge on my car. I got rid of it.

Thanks guys.

Btw, the ecu looked like it came out of 92 honda so it was pretty old.
 

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Try the p28 Ecu in another car. This helps rule out if the Ecu is bad or not. It could be the jumper harness that's bad.

The a7 is a ground trigger to the main relay. Putting a switch in shouldn't cause a problem. The switch might be bad. Disconnect the switch and hook the wires back up without the switch.
 

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Discussion Starter #4
Thanks for the response guys. I am throwing a CEL but I think it's because I don't have an o2 sensor at the moment. Well I have my o2 in my wideband but it's not calibrated at the moment and I'm not worrying about that until my tuner does my car next month.

I tested the pin coming off the conversion harness and I was getting 12 volts. I also bypassed the switch just to make sure it wasn't a bad switch. I got nothing. At first I thought it was a bad walbro pump but after putting my original ecu in, she primed no problem.

Trying it in a different honda would be a good idea but I don't know anyone with an obd1 honda right now that I could test it on. My buddy has one but he's going away for a month and his car is in a different city at the moment.

I ordered a capacitor rebuild kit off ebay for 15 bucks. I may try this. It's cheaper than buying another p28. I just hate the idea of throwing my new computer with the S300 in there until I figure out what caused this problem. Was it a bad capacitor that was on the verge of dying when I got it? or did I fuck something up in the wiring.

Thanks for the reply about the kill switch btw. I didn't think that would hurt it. hmmmm.....
 

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This capacitor here can cause fuel pump issues, it should be one of the ones in the so called rebuild kit. All chipping kits you order will come with a replacement.
 

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Discussion Starter #6
This capacitor here can cause fuel pump issues, it should be one of the ones in the so called rebuild kit. All chipping kits you order will come with a replacement.
Thanks man. That helps a ton. I just saved that image and I'll work on that capacitor first and test it after I get it soldered in.
 

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Discussion Starter #9
Update: I replaced the capacitor that was shown in the diagram and still nothing. I'm pretty sure I did a good job. After taking out the capacitor, the old one had leaked a bit of crusty crap out onto the board. I don't think it harmed it but it definitely showed signs of biting the dust.

Should you be able to see the solder coming through the same side of the capacitor? It soldered well on the back of the board, I'm just not sure how far the solder needs to go up into the hole to create a connection.
 

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Post a photo the ugly job lol as well as the board in general maybe we can spot something.
 

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Discussion Starter #11 (Edited)
Hey guys, sorry was in the process of moving so everything has been hectic. Here are some pics of the board that still won't kick the fuel pump on after replacing the C14 capacitor.

Couple things I noticed. The C14 capacitor has some leakage from the old capacitor on the board, could this cause issues?

Also the big black micro controller, it's the 207 one has little circles on it when you angle it in the light the right way. It almost looks like heat circles like it got too hot?

Lastly on one of the other pics I noticed a burn mark on one of the resisters above the bigger black one, you can kind of see it in the picture.

So are any of these or all of these major issues that could be causing this board to malfunction and do you guys think its from me hooking up something wrong? All I hooked into the conversion harness was the vtec wires, wideband to the ELD pin, and I did have a fuel pump kill switch on the A7 wire which is now not hooked up....... I don't see how any of these could have caused that.

I checked continuity on the distributor that I hard wired myself and all the wires checked out to the correct pins with my multimeter....

Maybe I just got screwed over with a bad ecu from ebay that was on its last leg? I should have checked it when I first got it :( Lesson learned.
 

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