Ok so im slightly stumped. My backup P28 ECU will no longer prime my fuel pump. Ran perfect for a week, i swapped back to my Neptune P06 and placed the P28 in its comfy spot in my sock drawer. 2 weeks after putting it away, i plugged it in as i wanted a fuel saver ECU for a long trip and my car wouldnt start. It will not prime the fuel pump. This is a gently treated P28 that is neither chipped, nor socketed, and went from running perfect to bleh.. I have changed nothing on anything. Car starts perfect on Neptune P06, nada on the other. Sigh.. I took a look at all the caps and they don't appear to have leaked, no foul smells, nothing. Is it now time to replace all the caps or should I just ditch it and pick up another P28?

 

change all the caps. the main cap is a deceptive bastard. being mounted flush to the board, you can't see under it to know if it has leaked or caused any damage. only way to know is to remove it and look at the board.

 

It's just really odd that it worked one moment, dead the next. Guess a refresh kit is in order.

 

This my friend, is EXACTLY what broken means. It was fine... and now it is not. The operational lifespan of the power capacitors inside an OBD-1 ECU is 8,000-10,000 hours. Many ECU's are reaching this functional state and failures are becoming increasingly more common. Replace the caps and cross your fingers... if that doesn't work, find another P28. Oh, and replace those caps RIGHT AWAY so that you have a new ECU to tuck into your sock drawer for many years to come.

 

if replacing the caps did not fix the fuel prime, replace IC17 also.

 

Haha! JRCivic.. Last statement is priceless! If a refresh is a bust, another will be in order. It's a drive for me to get them but the price is totally reasonable. I've removed what I suspected to be the problem caps already to avoid any major damage, if they've leaked. There is some discoloration on the board, but it is not mushy or hasn't harmed anything I can see (even with a magnifying glass), and no smell to it at all. **shrug**
replacement caps ordered, I should have an answer in a few days on this.

 

<<< purchased a custom "ecu sized" Tempurpedic mattress with 100% cotton sheets and pillow for the ecu to rest easy while it's tucked away, not in use. I also clean the pins daily with contact cleaner and sing a "vtec lullaby" before leaving it for the day.