When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Damn, I was afraid that the blown capacitor would not turn out to be the root cause. That really sucks.
Hopefully the short did not cause any other damage. Double check all your fuses, and otherwise I guess trace back those wires going to A25 and B1? Not sure what else to try at this point.
What event was it?
Triple checked all the fuses, but doesnt hurt to look even once more. That's what I will do today, trace those ylw/blk wires all the way to the source.
The event was Power Cruise @ Brainerd International Raceway and my ticket is for sale if anyone just happens to be in the area looking to race this weekend.
Originally Posted by LightningTeg
I thought that black w/yellow was the ignition on wire just going off memory. Goes to key switch?
Look at the diagram I posted above. Those 2 pins (A25, B1) run to a junction under the dash where it splits to my main relay, injectors, evap and has a random arrow going somewhere off of the injectors (mechanic friend is printing off a diagram of where that arrow goes to). Unless that arrow goes to ignition somewhere there isn't any ignition involved with those wires.
*Edit* - You know what, the more I think about it the more I think you're right about that blk/ylw going to the key tumbler. I remember seeing that in another diagram last night. I'll take a look at that wire too, I know it runs straight to the fuse box under dash.
Last edited by 9TechNine9; 08-02-2018 at 11:29 AM.
If you dont know how to read schematics then i would just stop before you fry another ecu
all the info you need is there in the pic
stop jumping wires to try and force the motor to turn over
I appreciate the input. This ordeal has forced me to learn to read the schematics. I have a friend that is a mechanic that is helping me read the diagrams and diagnose the issue. There is thought and intent behind the jumping of wires - to bypass, get power, etc.
We've concluded the wiring is fine through testing the injectors, distributor and again the main relay. Since we tested at the end of the line for the fuel and spark, it seems they are just not getting the signal from ecu. All those Blk/Ylw wires in question on the diagram above tested to be fine. We think there is something going on ECU wise. I'll need to make a call to Hondata to see if they can give me any insight. Still the same issue - No spark and no injector pulse. However, I'm not sure that this explains why there is no power to A25 and B1 (Which are in line w/ those Blk/Ylw wires).
I appreciate the input. This ordeal has forced me to learn to read the schematics. I have a friend that is a mechanic that is helping me read the diagrams and diagnose the issue. There is thought and intent behind the jumping of wires - to bypass, get power, etc.
We've concluded the wiring is fine through testing the injectors, distributor and again the main relay. Since we tested at the end of the line for the fuel and spark, it seems they are just not getting the signal from ecu. All those Blk/Ylw wires in question on the diagram above tested to be fine. We think there is something going on ECU wise. I'll need to make a call to Hondata to see if they can give me any insight. Still the same issue - No spark and no injector pulse. However, I'm not sure that this explains why there is no power to A25 and B1 (Which are in line w/ those Blk/Ylw wires).
Since this is a new to you ecu, I might run through the Hondata ECU troubleshooting checklist first.
Common problem solving for the s300. Please follow all these steps.
1.Download and install the latest version of SManager.
2.Check that the ECU has J12 (US) or J4 (JDM) cut.
3.Does SManager show 'Online' on the bottom left of the window when the ignition is switched on? If not, see USB troubleshooting
4.Create a new calibration from File->New, adjusted only for injector size.
5.Can SManager upload the calibration to the s300? If you can't upload a calibration, it is the ECU socketing.
6.Can SManager datalog from the ECU? If you can't datalog, then switch the on-board datalogging off, clear the stored datalogs and try again. If you still can not datalog then it is the ECU socketing.
If you get this far, then the s300 is working correctly. Any problems now are caused by the ECU, vehicle wiring, sensors, engine or calibration.
7.Start the engine. Can SManager datalog? If not, check that the plugs are resistor type and the thermostat ground is good.
8.Are there error codes? If so, find and fix the causes.
Since this is a new to you ecu, I might run through the Hondata ECU troubleshooting checklist first.
I ran through that when I first was having issues with the ECU getting power. Now that the ECU gets power through jumping it I'm basically stuck between steps 6 & 7. I'm positive that the s300v3 is good because I also swapped in my old chip with the same results.
I ran through that when I first was having issues with the ECU getting power. Now that the ECU gets power through jumping it I'm basically stuck between steps 6 & 7. I'm positive that the s300v3 is good because I also swapped in my old chip with the same results.
Yeah I guess there is still some other wiring issues if A25 is not getting power to ecu without jumping it. You'll need to trace that wire back. In this circuit is likely where something shorted out and burned up which could be why it is no longer getting power to ecu.
Hopefully whatever you find will also be the cause of getting no injector or spark.
The coil on the left needs to energize to allow current to flow to your exu and everything else
#7 is your positive going to your ecu injectors etc
that will only happen if the coil energizes and closes those tips. If you have positives and negatives to your coil and it isnt closing the tips (the click noise you hear) than you have a bad relay
Motivation and patience have returned towards the project. Im still battling with this electrical issue... Im getting 12v input through the Blk/Yel to the main relay, but not getting 12v output through the main relay to the Yel/Blk wires that go to the ECU, Injectors, etc. Tested continuity through those Yel/Blk wires and continuity is there. This has to mean the main relay is bad, correct?? I bought a new relay from autozone. Before, I was getting no power at all, now with the new relay im getting power at all times, when it should only be getting 12v at accessory and cranking/on. Super skeptical about this autozone relay and going to try OEM off of Craigslist.. Kind of doubtful that it will work, but everything I have tested has concluded the main relay is the issue. Just to confirm - Continuity checked on: Main Relay Ground, ECU Ground, Yl/Blk wires from Main Relay. Getting Power into Main Relay through Blk/Yel but no 12v output signal out of Yel/Blk. Can hear/feel relay clicking on.. Ripped entire dash and everything out, traced Yel/Blk Wires - no signs of any shorts, burnt wires, etc. Conjunction block seems ok, I believe we tested continuity on that too. All wires/connections seems to be normal thus far... I've been living vicariously through BoostedBoiz to get my fix lol
Motivation and patience have returned towards the project. Im still battling with this electrical issue... Im getting 12v input through the Blk/Yel to the main relay, but not getting 12v output through the main relay to the Yel/Blk wires that go to the ECU, Injectors, etc. Tested continuity through those Yel/Blk wires and continuity is there. This has to mean the main relay is bad, correct?? I bought a new relay from autozone. Before, I was getting no power at all, now with the new relay im getting power at all times, when it should only be getting 12v at accessory and cranking/on. Super skeptical about this autozone relay and going to try OEM off of Craigslist.. Kind of doubtful that it will work, but everything I have tested has concluded the main relay is the issue. Just to confirm - Continuity checked on: Main Relay Ground, ECU Ground, Yl/Blk wires from Main Relay. Getting Power into Main Relay through Blk/Yel but no 12v output signal out of Yel/Blk. Can hear/feel relay clicking on.. Ripped entire dash and everything out, traced Yel/Blk Wires - no signs of any shorts, burnt wires, etc. Conjunction block seems ok, I believe we tested continuity on that too. All wires/connections seems to be normal thus far... I've been living vicariously through BoostedBoiz to get my fix lol
He has like 2 new friends a season. Fixes up cars for them welds stuff makes power then dumps them like a bad girl friend and then has a drama explanation video, picks up a new gf, i mean bf to work on cars with and same stuff happens. The carlos dude should be around for a while tho lol. hondaru
Haha boostedboiz, youngstatic and cleetus FTW. This is what will get me thru the winter
Sucks that ur having these electrical issues. When all else fails, run your own new wiring and bypass all the BS. Or just go full race car with toggle switches and a custom relay/fuse board.
Haha boostedboiz, youngstatic and cleetus FTW. This is what will get me thru the winter
Sucks that ur having these electrical issues. When all else fails, run your own new wiring and bypass all the BS. Or just go full race car with toggle switches and a custom relay/fuse board.
Cleetus McFarland is actually here where I live this weekend at LS Fest. I live where corvettes are made and Holley performance plant is also here....... just zero import action really
He has like 2 new friends a season. Fixes up cars for them welds stuff makes power then dumps them like a bad girl friend and then has a drama explanation video, picks up a new gf, i mean bf to work on cars with and same stuff happens. The carlos dude should be around for a while tho lol. hondaru
‘lol. So true, but still impressed with some of the stunts they pull off.
I realized we had a 99 civic at my work, so I took my relay and swapped it into the civic just to confirm it was working - and it was. Back to the drawing board...
So wait, ur getting power into the relay but not out of it? Is power getting to it from the ignition switch that actuates the relay? Bad connection in the plug that goes to the relay maybe?
Or something in the ignition circuit that goes to the relay.
So wait, ur getting power into the relay but not out of it? Is power getting to it from the ignition switch that actuates the relay? Bad connection in the plug that goes to the relay maybe?
Or something in the ignition circuit that goes to the relay.
Correct. Getting ignition power to the relay - thats the Blk/Ylw I believe. Could be a bad terminal in the plug. Starting to think that coil in the relay isn't really activating (even though I can hear/feel it clicking..?) - everything downstream from it isn't working - ecu ign wires and fuel pump wire. Since the relay is confirmed to be good, it must be the ground.. Even though I swear I checked continuity in that. Next step is to make my own ground and try that out.
Ran my own ground to the relay, checked for continuity to make sure I was getting a proper ground. Still no luck. This is beginning to become comical! Having my coworkers come over to get yet another set of eyeballs on it when the rain lets up. If we cant figure it out, it's time to tap out and tow it to my buddy's shop where he and his dad can really dig in. Fingers crossed this really is just a small electrical hiccup. Even though it's cost me half the racing season, I love this car and I won't give up on it just yet
Ran my own ground to the relay, checked for continuity to make sure I was getting a proper ground. Still no luck. This is beginning to become comical! Having my coworkers come over to get yet another set of eyeballs on it when the rain lets up. If we cant figure it out, it's time to tap out and tow it to my buddy's shop where he and his dad can really dig in. Fingers crossed this really is just a small electrical hiccup. Even though it's cost me half the racing season, I love this car and I won't give up on it just yet
Glad you're not giving up on it Too many throw in the towel when having troubles they can't figure out (I'm guilty of this myself ) and post the car up for sale.
Keep at it and you'll get plenty of seat time next year!
After a much needed break, I'm back at it again and working on the integra. I've started from scratch to ensure I haven't missed something insanely simple. I've towed it to a friends where I have more room and tools to work on it. Quick recap - Cranking No Start. Drove to work and back, parked the car in the garage, a week later I was going to take it to work and that's when the cranking no start began. Found out the ECU had blown a capacitor, ordered a new P28 S300V3 package w/ upgraded capacitors, uploaded my tune, and still a cranking no start.
Here's what I've tried -Check all fuses, with extra attention towards fuse 31, 24, and 18. Ignition signal fuse was blown, replaced. -Replaced main relay w/ 2 brand new different units and tested current one to confirm its working (swapped into a civic and it started up). No foul odors, all soldered joints look fine -Checked all grounds - Main relay ground, thermostat housing ground for ecu, engine and trans ground -Tested ECU. When powered up (from jumper on main relay) there is power to IGN1 and IGN2. Nothing unusual inside, no foul odors. Contacted Phearable.Net (purchased P28 S300V3 package from them) and they confirmed that they test all ECU's 2 times 2 different ways -Unplugged anti-theft Viper alarm
-New battery
ECU doesn't want to power up on its own. No spark, no fuel pressure. I bypassed the main relay thinking that was it, but can only get fuel pressure. I'm getting fuel injector pulse when bypassing, but no actual spark from the plugs. Confirmed there is power to the dizzy. I'm thinking that whatever caused the capacitor to blow may have caused more damage and shorted a wire or something. I'm getting power and ground to the main relay through the trigger wires but its not making its way through to the other side (consequently the wire the ecu is powered off of), and even when I bypass that and get power through to the other side, it still won't start. All signs point to the main relay, but it's not the main relay - I've replaced with 2 completely different brand new units AND tested the one I have by swapping it into a civic. No foul odors from the relay, no cracked solders or anything unusual. Has anyone experienced something like this or know what is connected in this circuit that could have also been damaged/shorted?? I'll take any advice or suggestions I can get right now! This weekend I'm going to take another look at my engine/trans ground, my ecu and ICM in the dizzy. That's all that I can come up with for now
08-02-2018, 11:03 AM
Re: STC Hunter B18C Stock Block DC2 Street/Track Build
Too many throw in the towel when having troubles they can't figure out (I'm guilty of this myself 