Bad ECU?
Posted: Tue Apr 16, 2019 9:58 am
First let me start off by saying I know nothing about this stuff. Im a mechanic not a tuner. I work on a 89 CRX for some friends thats a race car that runs road racing. About 5 years ago owner #1, who is a friend, bought a camshaft, Hondata S300 ECU which i believe to be version 1 from my research (s300 - 12,598 is what is on the board inside the ECU), Boomslang obd0 to 0bd1 ECU harness and a new Richport distributor which was pinned for the OE connector to fit the OE harness. The ECU had a map to get the car started for the camshaft that was ordered. I wont say any names but this set up was bought from a very well known performance company. This company recommended a tuner and we installed everything which was pretty much plug and play and installed the camshaft. Took it to this tuner and lost 12 horsepower from our original set up on a stock ECU. We took the car to the track any way and needless to say changed everything back to our original set up and owner #1 scrapped the setup from this performance company
Now 5 years later owner #2 who is friends with owner #1 bought the car. They decided that they would try and just hook up the Hondata to the original set up with the car without the camshaft that was bought just to see what could be done and mainly because owner # 1 lost the paperwork on the camshaft specs. So the car was taken to a different tuner who came highly recommended by just about everyone in our area and right off the bat he says there is an issue with the distributor and found that it had been repined incorrectly and repined it correctly. He then tuned the car and got 9 horsepower from the car. The car ran great on the dyno.
This issue now that i am having is the car sometimes when started goes into a "limp mode" and will not rev over 4 grand. you can cut the car off and restart and it will do fine but not all the time. I connected a "check engine" light on the car because the OE ECU had a light in it to flash codes. When this car goes into "limp mode" the check engine light stays on solid. If the light does not come on when started the car runs great. Now on an OE ECU this means there is a problem with the ECU. I contacted the tuner and described the problem and he thinks the problem is the ECU also. I opened up the Hondata ECU and do not see any burn spots that is usually associated with this problem that I have seen in the past with OE ECUs. The tuner suggested that I check the Hondata board to make sure it is not loose and it is not. I also checked all the connections and they are ok also. I have done some research and correct me if I am wrong but this Hondata Board that is installed in the ECU has a battery in it that goes bad over time. I am wondering if this could be the problem. I have not tried connecting my laptop to the ECU because 1) it appears to take a special cable that did not come with the ECU and 2) I wouldn't know what I was looking at anyway.
So with all this being said. Any thoughts from anybody or suggestions. The car will be going to the track very soon but I am suggesting taking the OE ECU and distributor in case there are any issues with the car not coming out of "limp mode". The tuner says as long as the car is not in "limp mode" the tune will stay and it should run ok. So far we have gotten lucky with starting it but luck eventually runs out. Owner #2 really wants to run the Hondata system for the next race. This car has not run at the track yet only on the dyno when tuning.
I know I probably haven't given enough information that you really need but this is about all I know at the moment.
Thanks in advance for any info or suggestion you may have.
Now 5 years later owner #2 who is friends with owner #1 bought the car. They decided that they would try and just hook up the Hondata to the original set up with the car without the camshaft that was bought just to see what could be done and mainly because owner # 1 lost the paperwork on the camshaft specs. So the car was taken to a different tuner who came highly recommended by just about everyone in our area and right off the bat he says there is an issue with the distributor and found that it had been repined incorrectly and repined it correctly. He then tuned the car and got 9 horsepower from the car. The car ran great on the dyno.
This issue now that i am having is the car sometimes when started goes into a "limp mode" and will not rev over 4 grand. you can cut the car off and restart and it will do fine but not all the time. I connected a "check engine" light on the car because the OE ECU had a light in it to flash codes. When this car goes into "limp mode" the check engine light stays on solid. If the light does not come on when started the car runs great. Now on an OE ECU this means there is a problem with the ECU. I contacted the tuner and described the problem and he thinks the problem is the ECU also. I opened up the Hondata ECU and do not see any burn spots that is usually associated with this problem that I have seen in the past with OE ECUs. The tuner suggested that I check the Hondata board to make sure it is not loose and it is not. I also checked all the connections and they are ok also. I have done some research and correct me if I am wrong but this Hondata Board that is installed in the ECU has a battery in it that goes bad over time. I am wondering if this could be the problem. I have not tried connecting my laptop to the ECU because 1) it appears to take a special cable that did not come with the ECU and 2) I wouldn't know what I was looking at anyway.
So with all this being said. Any thoughts from anybody or suggestions. The car will be going to the track very soon but I am suggesting taking the OE ECU and distributor in case there are any issues with the car not coming out of "limp mode". The tuner says as long as the car is not in "limp mode" the tune will stay and it should run ok. So far we have gotten lucky with starting it but luck eventually runs out. Owner #2 really wants to run the Hondata system for the next race. This car has not run at the track yet only on the dyno when tuning.
I know I probably haven't given enough information that you really need but this is about all I know at the moment.
Thanks in advance for any info or suggestion you may have.