weavertime1

iTrader: (2)

I finally figured out why my ar was revving up strangly, but I still need to fix this tach issue. For whatever reason when I go above 6k rpms (which is very close to VTEC engagement as far as I can tell) the tach dops to zero. As soon as I let off and the engine drops below 6,000 rpms it works fine. I am running a OBD2A JDM GSR swap with the OBD2A JDM GSR ecu through a jumper harness. Everything else works fine, and there are no cels, even when revving above 6k. Any help would be grealy appreciated as he car is sold as soon as I get this fixed. Thanks!

mark@silbernage

It feels like VTEC is actually working? Sounds like a wiring issue, like perhaps the VTEC signal is touching something else on the way to the solenoid...

weavertime1

iTrader: (2)

Yes it feels like VTEC is actually working. I was kind of thinking bad jumper harness or wiring harness myself. I guess it could also be in the ecu as well. The harness is an oem OBD2 GSR harness which is not hacked up or anything. The only things I can add would be that the VTEC solenoid is the jdm solenoid with only one connection, not two like its USDM counterpart. I will keep checking the harness, but it looks very clean. I might try a jumper wire from the tach to the cluster to rule a wiring issue out.

1998GsRIntegra

Tach problems can be igniter related as one of the leeds off the igniter feeds the tach. I would check that also.

bluegatorade18

I don't know if this will help or not but I was having tach issues with my 97 gsr and it was because the ground wire inside the distributor was poorly connected.

14baldo66

had exact same issue in my 00 gsr, replaced dizzy, and problem went away

weavertime1

iTrader: (2)

Replaced the ignitor, and it does the same exact thing. I will takethe dizzy off and recheck all of the wiring one more time. You never know, and it sucks, because I sold all 3 of my OBD2 distributors thinking this one would be fine. Damn!

B00stedEh3

It's your JDM Vtec Solenid, or ECU. You'll need to purchase a USDM vtec solenoid that comes with the green oil pressure switch. Then run the wires to the ECU. You might need a chipped p28 ECU.

How do I know this? injust installed my JDM B18C GSR motor which I purchased from HMO and I ran into the same problem. fuel kept cutting off at 6k RPM and vtec wouldnt engage. I took it to the shop, installed a USDM solenoid and ran new wires to firewall to ECU and BAM fixed the issue.

However, my original ECU that came with my motor was throwing an ERROR code, which blocked off the connection to the knock sensor, so although vtec engaged it was very soft and light. My tuner recommended me to go with a p28 chipped ECU, with just a street tune. Now vtec kicks in hard :D

Hope this helps.

weavertime1

iTrader: (2)

I appreciate your idea, but if I am running the proper ECU with the correct jumper harness it shouldn't make a difference as the car/engine worked fine in Japan in the car it came out of. Do you understand what I am trying to say? If my JDM ecu is only looking for what sensors the jdm engine has there shouldn't be an issue. Now if I was trying to run the USDM ecu I could see how that would be a problem. I agree that an error shows up when trying to run diagnostic codes, but I would think that there is a communications error between the OBD2 scanner tool and the ecu, not an error from the ecu to the engine. I will keep your idea in mind and keep trying other things as well. As far as the P28 idea, that would also be fine if I was keeping the car, but in NY where it is going, you can't legally run an OBD1 ecu on an OBD2 car as the emissions check will not be able to scan for codes. Thanks again!

weavertime1

iTrader: (2)

Up...bump for more info and the last two posts.

weavertime1

iTrader: (2)

I fixed the issue last night. It was not the ignitor or coil, but the other sensor that is located in the distributor. Everything works fine now except for the fact that I still get an error reading when hooking up an OBD2 scan tool. I might just do the CKP trick and run my original USDM ecu.

vrrodri

cylinder position sensor?

weavertime1

iTrader: (2)

correct!

weavertime1

iTrader: (2)

I guess it could have also been a wire short within the distributor as well, but at least it is fixed!

msweett

Hey man, i know this is an old thread. But i have the same problem. although i didnt think its any of the sensors in the dizzy, because the problem only started occuring when i plug in an ecu that requires a wiring jumper harness. Where did you get your harness from? and did you have to do anytihng to it wiring related, thats.