car dies when connecting a pc

Menthos · Post by **Menthos** » Wed Sep 10, 2008 9:44 am

hello i have an honda civic with a b16a2 engine and ectune (not sure which version) i have been struggling with the wire harness for a few weeks, i have moved my fuse holder and alot of the wires i have extended... and well today i thought i was finished... so i tried to start the engine... it startet but after a few second the rpm starts to rice from about 400rpm to 1500rpm... anyone what could cause that? next i tried to plug in my laptop... but when i hit connect, ectune ask if i want the new rom bla bla... and when i hit \"no\" the engine stops and some clicking noises starts... what i found out is that the devices that makes the clicking noises is the main relÃ¦ and the EACV and \"purge cut solenoid valve\" on the IM and maybe the fuel injectors too... what i don't get is, why the ECU makes the sensors and main relÃ¦ go crazy when the computer want to datalog... the only thing the ECU should do when i connect, is send data to the laptop, or am i wrong?? hope someone can help me...

Bindegal · Post by **Bindegal** » Wed Sep 10, 2008 10:24 am

Make sure J12 in the ECU is cut, and also ensure youÂ´re using the latest USB comms drivers if using an USB--> RS232 adapter. ItÂ´s been a while since we tuned it, so youÂ´re probably running ROM55. Regardless, datalogging should work just fine. If all fails, look me up in a couple of weeks when IÂ´m back from the US, weÂ´ll make it work dont worry

/Allan

Post by **calvin** » Wed Sep 10, 2008 10:33 am

make sure u are running the lastest version

Menthos · Post by **Menthos** » Wed Sep 10, 2008 10:43 am

Bindegal wrote:Make sure J12 in the ECU is cut, and also ensure youÂ´re using the latest USB comms drivers if using an USB--> RS232 adapter. ItÂ´s been a while since we tuned it, so youÂ´re probably running ROM55. Regardless, datalogging should work just fine. If all fails, look me up in a couple of weeks when IÂ´m back from the US, weÂ´ll make it work dont worry /Allan

i will try to check that out... but the ECU should work fine... before i startet to "play" with the wire harness i had my laptop connected and it worked fine.. i know i use the lastest drivers cause i just reinstalled my laptop and downloaded all new drivers.. i had an suspicion that it had something to do with the EACV (or IACV?) since the idle is so high... so i tried to find the pin on the pinout diagram you gave me... and well it seems that something goes wrong.. on the diagram shows that pin A12 should be blue/black but when i try to use the Continuity beeper it goes to the yellow/black wire of the plug instead of the blue/black... where should the yellow/black wire be connected to?

make sure u are running the lastest version

well i use the lastest version of the free datalogger version... but it is Bindegal that has tuned the car for me, so i need him to install the new ROM... just found out that the vtec solenoid valve clicks too.. i think they click each time the computer tries to connect datalog...

HiProfile · Post by **HiProfile** » Wed Sep 10, 2008 12:03 pm

Sometimes people accidentally swap the IACV plug with the IAT plug. That will cause a crazy idle, and IIRC it can ruin some circuits. You may also have the purge solenoid plug (if you have one) swapped with something, that may cause issues. Another thing that happens is people swap the outer pins on the TPS connector (or rather, forget to on dpfi), so the ecu would sense WOT and work the IACV like crazy. Another thing that can cause erratic idle - a simple vacuum leak.

Menthos · Post by **Menthos** » Wed Sep 10, 2008 1:04 pm

HiProfile wrote:Sometimes people accidentally swap the IACV plug with the IAT plug. That will cause a crazy idle, and IIRC it can ruin some circuits. You may also have the purge solenoid plug (if you have one) swapped with something, that may cause issues. Another thing that happens is people swap the outer pins on the TPS connector (or rather, forget to on dpfi), so the ecu would sense WOT and work the IACV like crazy. Another thing that can cause erratic idle - a simple vacuum leak.

i have tried to switch some plugs to see if they were switched, but that made the RPM "jump" up and down so i switched back... i have looked at all the vacuum hoses but could find any leak or anything... still i don't get why the engine stops when i try to datalog..

RoadXY · Post by **RoadXY** » Thu Sep 11, 2008 8:46 am

Don't just swap the plugs if you're not sure!

HiProfile wrote: That will cause a crazy idle, and IIRC it can ruin some circuits

Look at the wire colors if the loom is all oem or use an ohm-meter to verify the correct wires! Look here for wiring info: http://technet.ff-squad.com/ [/quote]

Menthos · Post by **Menthos** » Thu Sep 11, 2008 11:15 am

RoadXY wrote:Don't just swap the plugs if you're not sure!
HiProfile wrote: That will cause a crazy idle, and IIRC it can ruin some circuits
Look at the wire colors if the loom is all oem or use an ohm-meter to verify the correct wires! Look here for wiring info: http://technet.ff-squad.com/

[/quote] i only swapped the TPS plug with the MAP plug... and only for a few sec. i have used an ohm-meter to verify the wire at pin A12... but i just need some info... what are the 2 sires to the IACV used for? my guess is one should be - and the other should be an ECU-controlled +... is this correct? cause i tried to ohm the 2 wires to the chassis but no connection...

Garrett · Post by **Garrett** » Thu Sep 11, 2008 6:28 pm

try another main relay

Menthos · Post by **Menthos** » Fri Sep 12, 2008 6:10 am

actually i think i got another main relay some where... i will try to switch

Menthos · Post by **Menthos** » Fri Sep 12, 2008 9:25 am

Garrett wrote:try another main relay

actually i got another main relay somewhere... so i could try it out

i have just tried to measure some more and found something that looks suspecius... according to ODB 2a pinout diagram, the A24 is IGP2 - power source... what is that and where should it be connected??

Menthos · Post by **Menthos** » Fri Sep 12, 2008 10:19 am

Garrett wrote:try another main relay

i have just tried but that didn't make any difference

RoadXY · Post by **RoadXY** » Sun Sep 14, 2008 1:33 pm

Menthos wrote:
Garrett wrote:try another main relay
actually i got another main relay somewhere... so i could try it out i have just tried to measure some more and found something that looks suspecius... according to ODB 2a pinout diagram, the A24 is IGP2 - power source... what is that and where should it be connected??

Should be an 12v.

Menthos · Post by **Menthos** » Sun Sep 14, 2008 3:49 pm

yeah it is an 12v but is connected wrong... need to know where it needs to be connected.. what i found out is that it needs to be connect to main relay but does it need to be connected to more or just the the main relay?

Menthos · Post by **Menthos** » Tue Sep 16, 2008 12:30 pm

when i turn my ignition on the engine light start to glow like normal, but then i flashes 2-3 times before it turns off... why does it do that??