ECU HELP!!

[lovemy89240]

Ok so my ECU fried and i was trying to find a new one, i found a thread on this site that told me to look at Jim Wolfs Site because they have an ECU ID page, does anybody know why Jim Wolf Tech has so many differwnt ecu numbers for the 1989 240sx, or why some of them show that the engines have different commpression ratios? Im trying to get a new ecu for my car and im looking for an auto non-cali ecu (im building an ITA car and dont want the speed limiter,), any help would be appriciated! The link is below!!! THANKS!

http://jimwolftechnology.com/wolfpdf/ECU-ID.PDF

[speedeast]

The ECUs are tuned for different scenarios... say you have pistons that increase or decrease the compression ratio: different ECUs. Then there is each scenario for whether you have an auto or manual transmission. Different ones have a different combination of rev limiter modifications, fuel map/timing curve, etc. They are designed to meet either Federal regulations or California regulations as well. These ECUs are tuned for performance, not so much OEM replacements.

[lovemy89240]

i understand that my reason is at the top of the page on the link it says core ID list and lists nissan parts numbers so arnt those ECU's listed stock OEM ECU's?

[speedeast]

That list is to identify the Nissan part # of the core for the ECUs they provide. You have to send in a core, their ECUs are modified versions of the OEM ECUs. The OEM part number just identifies the exact ECU it replaces.

[lovemy89240]

ahh well the second thing is, i didnt know the 89 240sx came with two different compression ratios, or is that just me being confussed, and if there is how do you know which one you have without doing a comp test? or is that the only way..

[speedeast]

The most common compression ratio is 8.6:1, but in the real early 1989 models the compression ratio was 9.1:1. You can tell by looking at your manufacture date. The ka24de also had two different compression ratios in the 240sx: 9.0:1 in the 91-93 models and 9.5:1 in the 94-98 model 240sx. I don't know the exact date in which the '89 model took on a different compression ratio, but they started manufacture of the ka24e in July 1988.

[lovemy89240]

So if my car was built on 11/88 that would most likely mean i have a 9.1:1 ratio and would need to find a an ECU with the same ratio... and on another note if i do have the 9.1:1 and i use an 8.6:1 it would run like crap or not at all correct?

[speedeast]

Well, the ECU wouldn't be 100% accurate for it, but I don't know how it would react. let me see if I can find some more information to help you identify what you have. Actually, ya know what... match the OEM ECU with the ones o the list and you'll have your answer.

[lovemy89240]

well there lies my problem and reason for the question my car is an 89 240sx with the
ka-e built in 11/88 its a cali car, but accordidng to the list the A11-B17 G13 (the ecu in my car) is for a 89-90 240SX M/t Cali S13-KA24E 8.6:1ratio, so could that be a problem?

ALSO
my car doesnt have any of the emmisions stuff (EGR, Cat, w/Headers) and after the car got warm and drove for a while the CEL would come on and the car would idle sloppy and dip below 400RPM, so maby theres a confliction between the engine and the ECU??

[speedeast]

11/88 might actually be late enough to have the 8.6:1 compression ratio... Call somebody at Jim Wolf or somebody @ a Nissan dealership to confirm. Your idle problem could be unrelated. If you no longer live in Cali, or never did, whatever, go ahead and get an ECU that isn't geared towards Cali emissions.