90 ECU Question

[D@nno]

Hey guys, I have an EPROM ECU from a 90 that I want to get a chip made for only problem is that it doesn't show knock at all. ECU sees knock and pulls timing accordingly but doesn't send the value to the logger. Sometimes I was getting 0 timing advance at WOT showing no knock. Switching to a different ECU fixed that problem, only problem is that it doesn't have the EPROM . Anyone know if this is something that can be fixed?

Thanks, Dan

 

[oldman]

Hey guys, I have an EPROM ECU from a 90 that I want to get a chip made for only problem is that it doesn't show knock at all. ECU sees knock and pulls timing accordingly but doesn't send the value to the logger. Sometimes I was getting 0 timing advance at WOT showing no knock. Switching to a different ECU fixed that problem, only problem is that it doesn't have the EPROM . Anyone know if this is something that can be fixed?

Thanks, Dan

Wiseman "steve" have fixed two 90 EPROM ECU's and burned stage 3 chips for me. PM him, I'm sure he will be able to help you with it.

 

[steve]

Anyone know if this is something that can be fixed?

Dan part numbers off the ECUs or pictures would help.

The datalogger reads the same variable used by the ECU to figure out what timing retard to use. It's not really possible that it would pull timing due to knock and not output the count. There must be something else wrong. Knowing what ECUs you have would be the first step.

Steve

 

[D@nno]

Hey Steve, these are some numbers off the EPROM unit with the problem. E2T34478-P, MD145903. On the side it has a large 5903. Its been a couple of years since i changed the ECU's but I remember going out and logging it getting maybe 5 degrees advance with no knock, switched the ECU and got the same advance and showed 30 some counts.

Ok now I'm a little confused, did some factory ECU's come with a socketed EPROM from the factory? Just pulled mine open and it has a blue socket with a locking arm on it that allows the socket to slide releasing the EPROM chip. There is a label on the EPROM with hand writing on it. first 3 letters are harder to make out either EOH or E0N, then 40070B-06f-4h2. On the EPROM itself there is some stuff stamped: M5L27128K-1, 840104, Japan.

 

[D@nno]

OK after a little searching around:http://www.dsmtuners.com/forums/showthread.php?t=185468&highlight=factory+socket. This is the same socket mine has. Same style label on the front except that it has C.S instead of engineering sample. That still doesn't help me with the no knock showing problem though.

 

[steve]

Interesting, That makes two "prototypes" that have popped up.
I'm still waiting on a copy of the code from that first one, So I can't speak to what software version was in it or in yours.

Steve

 

[D@nno]

OK, did a little experiment tonight. Went for a run with the current ECU and leaned it out to get some knock showing, got between 13 to 18 counts of knock. Timing started at 13 went up to 16 then fell off to 14 by redline. Put in the EPROM unit, it showed no knock at all, but timing started off at 7 degrees and slowly climbed to 12 by redline. Check engine light was coming on every once in a while and it was indeed the knock sensor. Computer must be running in safe mode. The light would go off if you wiggled the wires at the plug or tapped on the ECU. So the ECU must not be seeing the knock, and the problem lies in the wiring, which i doubt since the other ECU works fine, or a problem in the ECU itself.