Within the last few days my car has started breaking up in boost/under load. This is on a car with Hondata CPR setup. I know it's ignition related because 1 of the datalogs showed a brief AFR spike over 16 with boost over 10 psi and the engine didn't grenade, AFR went right back to 12. Fuel pressure is spot on. After trying new plugs, coils, and cleaning the grounds I swapped to another working S300 (it works but has issues and the TC circuits are screwed) and the issue disappeared completely (same exact calibration, no changes). I put the suspect S300 back in and the issue returned.
I'm assuming my relatively new S300 is the problem. Is there any way to figure out what is up with the S300 or is it now garbage?
Thanks.
If you need more info about the setup I can add it. I have datalogs of the breaking up but after discussing with my tuner we are 100% sure it is ignition related.
Breaking up in boost/under load
Re: Breaking up in boost/under load
It will not be related to the s300. What do you mean by screwed TC circuits?
Re: Breaking up in boost/under load
The TC circuits in the ECU don't workSpunkster wrote:It will not be related to the s300. What do you mean by screwed TC circuits?
This post covers the TC issues. http://www.hondata.com/forum/viewtopic. ... 779#p79779
I think I need to rephrase this. I guess the problem isn't the S300 but the ECU it is installed in (I'm assuming in both cases) does that sound correct?
Re: Breaking up in boost/under load
I highly recommend that you try this in a different ECU as it sounds like the ECU's you have may not be in 100% working order.
Re: Breaking up in boost/under load
I don't really have the means to try it in another ECU. I'm not confident enough with my computer board skills to try installing or removing the S300 from an ECU.Spunkster wrote:I highly recommend that you try this in a different ECU as it sounds like the ECU's you have may not be in 100% working order.
I know my old ECU is not 100%, far from it. I guess this new one now has issues.
Would you have an idea where I could look on the ECU to see if there is damage to it.
Guess I have some decisions to make.
Thanks for all of your help.
Re: Breaking up in boost/under load
You probably won't be able to see anything visible. These ECUs are getting to be 20-25 years old. You can buy a socketing kit for a replacement ECU or buy an ECU that has already been socketed for s300. putting the s300 once it is socketed is not hard at all.
Socketing kit: https://www.hondata.com/accessories/s300-install-kit-us
Socketing kit: https://www.hondata.com/accessories/s300-install-kit-us
Re: Breaking up in boost/under load
So last weekend I put the ECU (S300V2) that had been working properly in the car but then it started doing the same exact thing. So I'm not sure it is ECU related. I went through all the wiring. The grounds are good, cleaned and double checked them. I was watching the LEDs on the CPR box and they don't seem to change from when its stumbling and when it is acting normal. Is there any way to test the CPR box? I tried swapping out my new OEM distributor for the old OEM one, no difference. I even pulled the timing belt to make sure something wasn't going on there. At this point I swapped back to the V3 ECU.
This morning, after putting everything back together from checking the tbelt, I would key the ignition to start the car and I would just get a click. Every now and then it would turn over but wouldn't catch (battery voltage was displayed as close to 13). I unplugged the ECU, plugged it back in, and uploaded the calibration file, keyed off the ignition, keyed it back and it started up perfect. That issue hasn't been repeated. I may try going back to a non CPR setup to see if that makes any difference.
Any ideas or help would be appreciated.
TIA
This morning, after putting everything back together from checking the tbelt, I would key the ignition to start the car and I would just get a click. Every now and then it would turn over but wouldn't catch (battery voltage was displayed as close to 13). I unplugged the ECU, plugged it back in, and uploaded the calibration file, keyed off the ignition, keyed it back and it started up perfect. That issue hasn't been repeated. I may try going back to a non CPR setup to see if that makes any difference.
Any ideas or help would be appreciated.
TIA
Re: Breaking up in boost/under load
Well I went back to the stock distributor and plug wires. Still breaking up but I have more information. It is only happening when the car is fully warmed up/heat soaked.
With ECT 177-180 and IAT mid 80s ran perfect, slightly rich but nothing terrible. I pulled off to the side of the road, let the car get heat soaked and drove it again. With ECT 190-195 and IAT 105 ish it was breaking up. I don't think this is related to Hondata. It is either the tune (but we had it fully warmed/heat soaked when it was tuned on the dyno), something with temp comps, or something related to a sensor. TPS and MAP signals are solid. Not sure what other stuff to look at.
With ECT 177-180 and IAT mid 80s ran perfect, slightly rich but nothing terrible. I pulled off to the side of the road, let the car get heat soaked and drove it again. With ECT 190-195 and IAT 105 ish it was breaking up. I don't think this is related to Hondata. It is either the tune (but we had it fully warmed/heat soaked when it was tuned on the dyno), something with temp comps, or something related to a sensor. TPS and MAP signals are solid. Not sure what other stuff to look at.
Re: Breaking up in boost/under load
It could be any number of things, but it does look like you have ruled out the ECU or Hondata. It could be wiring that is old and brittle and sensitive to heat. It could be a faulty sensor or even something mechanical that is only affected when hot. If it is tuning related, your best bet would be to adjust one thing at a time to rule that out.