i'm pretty sure i know that the problem is but i need some more input. here is as much information as i can remember:

when my del sol was an automatic with a d15b7.. it would not turn on sometimes and eventually stall. why? now i swapped in a jdm d15b and sometimes it would do the same thing. i searched and came up with my main relay being the problem. i just turned off my car and it wouldn't turn on at all. lights up, no crank... i just wait for about an hour and bam... fires up again.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by idriveadelsol7 &raquo;</TD></TR><TR><TD CLASS="quote">i searched and came up with my main relay being the problem.</TD></TR></TABLE>

Sounds like what your problem is. When my main relay died, it did the same thing. Either replace it, or re-solder the pins. Main relay will either kill your fuel pump, or you fuel pump and ECU. When it doesn't crank, can you still hear your fuel pump? If not, I'd bet it was your main relay.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by qat727 &raquo;</TD></TR><TR><TD CLASS="quote">
Main relay will either kill your fuel pump, or you fuel pump and ECU. When it doesn't crank, can you still hear your fuel pump?. </TD></TR></TABLE>

what do you mean by kill?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by idriveadelsol7 &raquo;</TD></TR><TR><TD CLASS="quote">

what do you mean by kill?</TD></TR></TABLE>

Kill the circuit... Leave an open, so that it isn't a complete circuit. Parts aren't dead, they just aren't getting any electricity. From the best of my understanding, the relay trips power to the ECU, then the fuel pump. ECU has to be getting power for the fuel pump to be getting power, so far as I can tell.

 

re-solder the joints which have a minute crack around the joint, hard to see but its visible, i found 3 cracked joints, re-soldered them and havn't had a problem since!