I'll test the ISC tomorrow to confirm it's bad, but suffice it to say something bad happened and completely fried the ISC driver. The ECU seemed fine up until recently, when I installed the WB. I mentioned this to Thomas, who seemed to think the WB install couldn't have caused the issue. That was a relief.
The ISC did just fine, though as stated already - took a few more cranks and sometimes a second of throttle to get it idling normally. Btw, 3 out of 4 adjusters were easy as pie to adjust down.. the runt of the litter was a B*tch! Blow torch and all it took like an hour and a half to get it all of the way down.
As I work through many, many issues with 1587, I have found that I have a blown ISC driver (IC105). According to ECM Tuning, the drivers do the following functions: IC104 controls ECU pin 14 ('90) or 6 ('91+), MAF Reset signal. The other half of the chip is unused on US DSMs. IC105 controls...
Yes newbie question here. What other throttle body will mate to GVR4. I am looking to get one locally to remove the isc and plug the coolant line. Would N/T throttle work ok? or not because of the TB elbow? detail list would be greatly appreciated.
You want the ISC in the middle of it's range, while adjusting the BISS for optimal setting (Our idle should be 800 RPMs). But what exactly is the middle of it's range? If you log it, I think it goes anywhere from 0-100+. Does anybody have hard evidence on where it should properly be set @ idle with a logger using MMCD?
I have 280* cams, and with the ISC set to about 30 steps at warm idle, I can reach in through the window and start the car even at 15-20*F outside. Throwing the deadtime and MAF readings way out from a base number, just to achieve what looks good on the screen, probably isn't going to make the car run better/right.
Hey guys, I have been having trouble getting a decent idle recently. I have been running a few months with the ISC unplugged while I try to figure out the problem. Stock 91 VR-4, using TMO to datalog. The ISC stays around 76 or 77 steps during normal idle, while the engine is around 1500 rpm...
Let me know if this sounds right or wrong. I have tested resistance to the ISC coils and they all check out okay. The TPS sweeps cleanly from 0.63 to 5.00v and it looks stable in the logs. The MAF was working fine prior to the valve cover change, I removed it with the coupler and air filter attached and sat it on the bench until re-install.
So replaced the ISC after my last ecu blew a driver, I replaced the ecu and rewired the pump as some of you may remember, I have a bad idle surge now, and I adjusted the biss all the way in and still idles and fluctuates around 12-1600 rpms, The ISC I pulled out to see if it'd move with the key...
I want my ISC because it makes the car much nicer to drive in traffic and it saves on the footwork needed to keep it from stalling. I had no ISC for a long time and it sucked having to balance between lights being on, fans being on, etc vs having a livable idle speed plus during the winter its 30-40 degrees in the morning and 60-80 in the ...
