Bad ECU?

s300 and SManager software questions & answers
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monzster
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Bad ECU?

Post by monzster » 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.

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Spunkster
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Re: Bad ECU?

Post by Spunkster » Tue Apr 16, 2019 10:55 am

Post pictures of the bottom of the ECU where it has been socketed for use with the s300. It could also be an issue with the capacitors on the ECU. We sell a kit to replace them: https://www.hondata.com/accessories/capacitor-kit

monzster
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Re: Bad ECU?

Post by monzster » Tue Apr 16, 2019 5:28 pm

I think this is what you are asking for. I have never soldered a circuit panel before but this looks rough in some areas.
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Spunkster
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Re: Bad ECU?

Post by Spunkster » Wed Apr 17, 2019 9:01 am

Who socketed this ECU?

It looks like some of the solder joints are bad and could be the cause of the issues.

monzster
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Re: Bad ECU?

Post by monzster » Wed Apr 17, 2019 11:38 am

I do not know, it was bought as a package deal from a well known performance company. 5 years ago it was ordered with a camshaft, boomslang ecu harness and new richport distributor that was apparently pinned incorrectly. I didnt want to list the name of the company because I didnt know if it was proper to do that. My wife was looking at the circuit panel and she said it also looked like there were cuts in the panel across some of the raised areas that run from solder joint to solder joint. You can see some of them in the first picture listed as above right.

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Spunkster
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Re: Bad ECU?

Post by Spunkster » Wed Apr 17, 2019 12:36 pm

You might want to contact the company that did the work and explain the situation and see if they can check the soldering on the ECU.

monzster
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Re: Bad ECU?

Post by monzster » Wed Apr 17, 2019 5:49 pm

I doubt they will do anything about it after 5 years and being the second person to own it but I guess a email or phone call is worth a try. It's ashame because this ECU has only been used twice. I appreciate you taking a look at the pictures and giving your opinion. I will talk to the owner of the car to see what he would want to do. Just in asking. If they do not want to pursue it with the other company. Do you think this ECU is salvageable or should they just start from scratch and get another ECU with the newer version. Thanks again.

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Spunkster
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Re: Bad ECU?

Post by Spunkster » Thu Apr 18, 2019 9:21 am

We can take a look at it, but you will have to pay for shipping both ways and if it can be repaired there will be additional charges.

Since this is an older s300 as well you may want to consider upgrading to the version 3 s300, as it has no battery to go bad and has additional features as well. Details on upgrading can be found at: https://www.hondata.com/downloads/s300v ... e_form.pdf

monzster
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Re: Bad ECU?

Post by monzster » Fri Apr 19, 2019 12:16 pm

It makes more sense to me to just upgrade but I will leave it up to the owner of the car. I really appreciate your help with everything. The owner did find the original receipt and upon doing some more research it appears that the performance company was just a middle man and a different company actually did the work for them and they just sold it to the first owner. Again thanks for your help.

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