hytechb20

long story short i swapped my eg with a b16a2 with a chipped p28 everything ran fine for about a month. i had 3 cel codes o2 sensor, iat, tps. i drove the car only to work and back, but randomly i drove to work fine, got off went to start it and didnt hear the fuel pump. i replaced the pump with a walbro 255 and bought a new main relay and nothing. no prime still. i put the stock p28 d16z6 ecu in and the car started perfect.

my questions:
i checked the ecu and it looks good no burnt caps or solders broken. qm3 looks good also and isnt that whats suppose to power the main relay? anything i should look for besides caps?
i had this ecu in my b20vtec with a vafc and it ran perfect on that motor but that was three years ago since then its been in storage but a tiny bit of oil was on the ecu before install so i cleaned it good before i actually installed. again it ran the car fine for about a month before crapping out on me.

all my searching has came to checking blown caps and qm3. any way i can jump the fuel pump so i can use this ecu until i find a p30 or repair my blown caps on a spare p30 i have. i hate running the motor on a sohc ecu, i dont want to mess up the motor.

grumblemarc

iTrader: (4)

Er. Why don't you get the proper ECU for it since it appears to be stock? You can run wires from the fuel pump straight to the battery as a hack.

hytechb20

thats my plan, when the chipped p28 wouldnt prime the pump anymore randomly i sourced a jdm p30. when i bought it i was told it was in working order so i plugged it in ran it for about 5 hours crusin on the highway about 70 in fifth on my way to a work meeting and the motor was sputtering bad so i pulled off the highway, lucky had tools and my stock p28 in the truck so replaced the ecu. upset that i just purchased this ecu the day before and was told it was in working order i opened it and saw that c14 was burnt so im currently looking for someone whos good at soldering to replace all the caps so i can run that ecu.

side note when i purchased the jdm p30 i unplugged the ecu fuse and neg battery terminal so i can reset it and when i pull down the road tried to take it to 8k and fuel cut off was at about 7.2k. this is also a virgin p30 never chipped or anything. whats up with it cutting fuel at 7.2ish k?

grumblemarc

iTrader: (4)

Let's stick to one issue at a time shall we?

hytechb20

clearly it'd be best to run the correct ecu i.e. the p30 i have but needs new caps. you said i can hack my fuel pump to the battery. stupid question but would hacking the pump to the battery for say about a week hurt anything else? id rather do that and run the chipped p28 then the sohc p28 since i commute average 70 miles 5 days a week.

grumblemarc

iTrader: (4)

Not sure TBH. I've read in the past of how people have bypassed problems like this in this manner but they never report the effects.

hytechb20

gotcha, well if anyone else has some input as to what to try in the mean time itd be much appreciated.
thanks grumblemarc for the input

NotAJDMFanBoy

C14 is known to go out. All you need to do is get the same size or larger capacitance capacitor and replace it. Just look on the side and the capacitor should say something like 35V 220uF. There are electronics shops around that repair TVs and stereos and such, they should be able to do that for you. Or put up a listing on Craigslist and see if anyone can chip ecus.

If you're going to bypass the wiring for fuel pump, I would suggest running a 12 volt relay for it and not just a switch. If you think about it, it wouldn't really that much different than the original way it was wired. It it controlled by the main relay originally, you'd just be running it off another relay. The injectors are closed until the ecu sends power to open them. There is a fuel pressure regulator that will return the fuel to the tank if there's too much pressure. I'm no expert, but it doesn't seem like it would hurt anything. Maybe just wire the power to the switch for the relay to an ignition switch power source so it won't stay on if you turn off the car.

hytechb20

yeah ive read about c14's.. my chipped p28 has nothing blown or damage seen to the naked eye so im stumped why its not priming the fuel pump. as for the jdm p30 c27 is blown. im going to end up replacing all the caps on that ecu for sure. my buddy works for a audio company so hes skill at this kinda stuff and repairs. as far as running a relay from pump to battery im most likely going that route since this single cam ecu is hurting my motor it seems.

i took a pic of my jdm p30 c27 blown cap.. would anyone say this is repairable? or did the board get burnt up to bad?

again if you know why my p28 would randomly stop priming my fuel pump or had this happen to you please share some info

grumblemarc

iTrader: (4)

The main relay primes the fuel pump.

Ej8_KiD

Sorry to bump an old thread but I have the same problem but mine has q31 burned , but from the research that ive done this q31 has nothing to do with the fuel pump , anyone knows that controls the fuel pump on the ecu?

nemesis3888

bad IC12 maybe

Former User

Old thread closed.