Integra DC5-R rebuild wont start / USB cant connect

K-Series Programmable ECU installation questions / support issues
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6nfanatic
Posts: 21
Joined: Mon Sep 17, 2018 4:13 am

Integra DC5-R rebuild wont start / USB cant connect

Post by 6nfanatic »

Hi,
im having issues with my ecu/car.

Im building my dc5 as a racecar. I removed everything from it and got a cage welded in. Last year the car was running fine with a kpro i borrowed from a friend. No issues.

Now i rebuilded it and got a kpro4 a few weeks ago (send in my PRC ECU so the kpro is new) and tried to start it but i am running in some issues that are non-consistent. I try to do a timeline:

01.01.2022: Hooked everything up, connected the laptop with the kpro4 and wrote the map. I am using a map from the vault where i changed the inj size to 440 (since im running RC engineering SL4-440 https://www.rcfuelinjection.com/Store/p ... d-injector). I also changed the Deadtimes to the value thats in the link above (i used the 60PSI row which should fit to the stock return valve with a walbro 255).
Other then that the map was unchanged mostly.
=> I tried to start it but it was just missfiring like crazy, from the exhaust and also from the intake?! dont know why.
Then i talked to my tuner (who is 400km away so he cant come over). He told me to set the VTC table to 0 and reduce the fueling on the 0° map to -25%. I did that but then all of the sudden i couldnt connect to the ECU anymore. The Hondata software froze and crashed when i tried to upload the map. When i was connecting to datalog then it would show the values of the engine (on ignition) for a few seconds and then it would disconnect to the ECU. Also when i just plugged in the laptop i could her the windows USB sound popping in as if the connection would go on and off.

I tried a different laptop and that worked lol. So i wrote the map and did a datalog i am attaching. The car couldnt start, it was missfiring like carzy and did showed some rpm but i was not able to keep it alive without throttle. The car responded very poorly to throttle but that might be because of the not fitting map. I then decided to go to bed.

02.01.22: Next Day:
I got in the garage, and the car started lol like if nothing happened and was idling quite fine.

10.01.22:
Car wont start again. Now its the worst. It will fire from here to there after the starter is running for like 15sec. After half an hour of testing and trying different thing, i tried to connect the other laptop that worked last week but also that laptop couldnt connect anymore.... So i tested further and then after 30 min could keep the engine running but only on 2 cyl. It was running very very poor.

I tried the ecu of my friends DC5-R in my car and that didnt worked either (its a stock ecu).
I tried my kpro4 in his DC5-R and the car would start up immediately and i could connect to the laptop with no problems!!


=> So there must be something at my car thats causing issues but i dont know what. I have a feeling that it is ground related but i have everything thats recommended:

-Inj-Ground at the cyl-head
-Groundcable from a bolt of the shiftermechanism to the chassis
-Groundcable from the timing side of the cyl-head to the chassis

(-And also the two grounding below the headlights if they matter)

Do you guys have an idea where i could look? Im actually unsure of the groundcable thats between the cyl-head and the chassis. Isnt that a groundloop?! Since there is also a groundconnection between the transmission and the chassis?! I did it like it was published in the tech-document on your homepage).

Thanks in advance!!
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Spunkster
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Posts: 22745
Joined: Fri Sep 20, 2002 5:06 pm
Location: Hondata

Re: Integra DC5-R rebuild wont start / USB cant connect

Post by Spunkster »

If it is starting on another vehicle, but another ECU is not starting your vehicle then it sounds like there is either a wiring issue or a mechanical issue with your vehicle. You will have to use process of elimination to narrow down where the problem is.
6nfanatic
Posts: 21
Joined: Mon Sep 17, 2018 4:13 am

Re: Integra DC5-R rebuild wont start / USB cant connect

Post by 6nfanatic »

Hello,
after countless hours of diagnostics i found the issue: I had the wrong Throttlebody Gasket which had a channel from the iavc to after the butterfly. I dont have the iavc connected so i assume it is just plain open without wires. And because of that it would wouldnt start.
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