Hondata

Hey Guys,

So I have been fighting this issue with my car for almost a year now & I feel I have exhausted every thing I can at this point to figure out why this is happening. Quick back story, car was tuned on a new turbo in May of 2022 & ran amazing making almost 40 PSI and around 700WHP. Other than the turbo, nothing else was changed and tune from previous turbo was perfect in cold or warm weather. Every winter I would pull my injectors to have them clean & flow tested which once again I did in January of 2023 as peace of mind. Injectors came back perfectly fine & all flowed as they should according to my tuner. Well come May of 2023 when I started the car up for the first time after installing the cleaned injectors, I noticed my cold start AFR's were a little leaner than usual sitting round 12-13 instead of 11-12 which didn't bother me much. However, as soon as my coolant temp hits 150-155 degrees Fahrenheit, its like a flip of switch & my AFR's will immediately go to reading --- on the gauge because its so lean and the idle is audibly different almost like its mis-firing. Even when applying some light throttle, the AFR's will sit very lean until I apply more then 5-10% throttle then it will register on the gauge between the 13-15 mark but even when holding the throttle it will slowly begin to creep back to lean again. I pulled the plugs and they are very white so clearly it is running very lean as shown on the AFR gauge reading ---. I have checked everything from replacing my Walbro 525 pump & new strainer, confirmed fuel pressure is correct at idle (51 PSI) along with pinching the return line which sky rocketed the pressure to 100+ psi, checked inline fuel filter, had injectors cleaned/flow tested again, checked timing & ignition/spark which was perfect at 16 degrees, did a compression test which was around 200 psi across the board & verified all sensors look to be reading as they should. I sent a datalog to my tuner & even he is stumped at this point. I don't know if it will help much but I have attached multiple datalogs of the idle from a dead cold start to fully warm to see if anyone can help me along with the tune I am currently running. The car does have Kelford 176T camshafts, so that is why the idle is higher than normal. Any help is greatly appreciated as I am honestly so burnt out at this point being that the car isn't even drivable because it runs so lean & breaks up really bad even when trying to cruise down the street. Would really like to just enjoy this car again as it has been super solid for years & has never given me problems until now. Thank you.

You could have an air leak somewhere as you are not getting very much vacuum at all.

Thank you for the reply. I have been considering this also but I have performed a smoke test using a snap on smoke tester from our shop through the brake booster line before the check valve & also the blow off valve line which both lines go directly into the ports of my Victor X manifold with the turbo inlet blocked off & wasn't able go find anything. Machine was on the highest setting also so I would have figured something would show itself. However, I am still not sold as it really does seem like an air leak at this point since nothing else has changed besides pulling my injectors & re-installing them a few times after finding this issue. I did check my old logs when I was already tuned with these cams some years ago & found due to how much overlap they have that I always idled around 7-10 inHg when warmed up but I will say it seem to just stay around 7 inHg now when warm. Do you have any other good known ways to pin point air leaks? I know I could always try some carb cleaner and spray it in certain areas to see if it raises the idle but never though that was he safest way lol. Intu is greatly appreciate though & I hope working back & fourth a bit can get this figured out!

If you have not replaced the injector seals that could be a source of an air leak, especially since you remove them regularly.

Good point, I will go ahead & replace them to see if that changes anything then will report back with results. Just to confirm, you are talking about the cushion seals that sit in the intake manifold that the injector seat into correct? Also, is there a set height that the injectors should sit at for sealing purposes? I did use to run about 3 small washers on the rail where each mounting bolt would go through but decided to remove them as I didn't feel think they were necessary but now I feel that this might have affected how the injector seal is sealing now as if the injector might be sitting to far in now? I made this change with the removing the washers when I had installed the cleaned injectors & this all began. Just a thought Id figure I would mention.

Anything you have changed may be the culprit.

So update, changed the injector cushion seals as suggested and no change at all. Any other suggestions? Feel like I’ve checked everything at this point with no luck at all. Pretty frustrating.

I decided to open up my ECU to see if I could see anything that might be culprit, all connections looked good & the Hondata board looked good also but I did notice the IC12 chip (Excuse my ignorance as I don't know exactly what it is called) has rust on 3 of the 4 solder points. Everything else is really clean on the board. I did notice the other day after letting the car idle for a bit and shutting it off after diagnosis, I went to turn it back on right way and my pump wouldn't prime but the relay would just click. After letting it sit for 30 min or so everything went back to normal. Could this possibly be a contributor to this? I am just spit balling at this point as I don't know what else could do this.

Welp, after gently cleaning those solder points my fuel pump will no longer prime at all. I also noticed after erasing my ECU that when I uploaded my calibration again it would not display any of the fuel or ignition tables besides “21%” in the top left box but everything else Is blank. I uploaded multiple maps with the same problem. Something tells me this is all ECU related now. If someone could give me some decent input it would be appreciated. Thank you.

Post pictures of the areas in the ECU you saw problems as well as the solder joints for all the s300 pins on the bottom of the ECU.

Please see photos below

Other attached photos, couldn't upload them all at once. Let me know if you need anything else!

It looks like there may be some bad solder joints for the 4 pin connector and the 2 14 pin connectors.

Okay, so I should start by having someone who knows what they are doing re-solder all the pins for the Hondata board? Is this a known issue that can happen after some time? Your product has been great & I got this installed by Phearable.net around 2012, so it has been awhile with no issues but now suddenly all these weird symptoms out of no where. I just figured at this point it has be ECU related since nothing has changed in my setup.

That would be a good place to start as they do not look good and may not be making a good connection. If there are still issues, you may want to try replacing all the electrolytic capacitors in the ECU.