So i have a 94 hatch i’m swapping a b20b into with a integra LS transmission, Integra LS p75 ecu chipped with hondata, p75 intake manifold, skunk2 70mm throttle body, aeromotive 340 fuel pump and a short ram intake. we got the car started and it idles but it sounds like it is starving and wanting to die out. the motor is in time 100% correctly and i have triple checked. the distributor is less than a year old from my other swap and all internal parts have been replaced for safe measures. my guess would be the stock tune it is on is not putting out enough fuel for the bigger throttle body. i can’t see the air fuel ratio as of now because i haven’t set up my gauge yet. any help is appreciated. all of my mods i’ve done are listed. 🙏🏻

 

Your first step is to get your wideband installed and wired to Hondata so you can log your AFR.

Do a datalog while it's idling like crap, then review each sensor output in detail to see if there is a clue. Also, see if there are any errors / CELs.

Have you looked at the tune that is loaded into Hondata? Unless you uploaded it yourself, it could be anything - if the injectors and/or MAP are sized incorrectly in the tune, it will run bad or not run at all. It could also be a corrupted tune, even if you were the one to load it. This is a common occurrence with Hondata.

What is your static fuel pressure set to?

I think it's highly unlikely that a 70mm throttle body being mismatched with the tune (especially at idle) is your problem.

 

thank you for the feedback. i’m getting 0 CEL, i uploaded the b20 basetune from a new calibration on hondata, and i will have to double check the fuel pressure. the MAP sensor and injectors have been reset to stock form. How would i determine if the tune is corrupted? i also am stuck with setup of the wideband. it’s all plugged up and everything but i’m not getting a reading. do i have to set it for an open loop or closed on the tune?

 

update. we have 3 codes pop up. one for injectors. another for ELD detection, and finally the oxygen sensor. the o2 sensor is because exhaust isn’t hooked up yet properly. and injectors seem to not be firing on 2 of them 1 and 2 are cold and 3 and 4 are warm. i have no idea why the ELD is on or if it matters. i’ve read it won’t affect certain ecus. any ideas on why the injectors aren’t firing. i’m troubleshooting right now as we speak just thought i would update what i’ve found.

 

To check the tune, you could try downloading the tune from the S300 to look at it in SManager, but the easiest thing to do would be just re-uploading the last known good tune. For some reason, Hondata will corrupt the tune about half the time or more if I have the laptop plugged in before I turn the key on. My method is to turn the key to the on position (where you can hear the fuel pump run) but not crank it, with the laptop disconnected. After that, then plug the laptop in and connect.

You need to disable the ELD in your tune, and you need to connect your wideband to D10 input on the ECU (this is originally the ELD input). You'll also have to remove R136 and R138 from the ECU. Until you get your wideband connected, I would just run in open loop for initial testing, but try to get your wideband connected before you really start driving it so you can switch back to closed loop for protection. If you're getting the O2 heater error code, you can disable that in the tune also.

For the injectors, trace the wiring and make sure it is correct. You can ohm out the injectors too - you should get 10-12 ohm or something like that. If not, you've got a bad injector coil. Even if all the injectors test out good, you may still have bad injectors. You can also try swapping the injectors around and see if the problem follows the injector or if it stays with the cylinder. That will tell you if you've got an injector issue or a wiring issue.