awilson40

Radio Shack....Its a electronics chain.
Any electronics store / supply should have a 1.8k 1/4 watt resistor.

Bri Bro

Buy two sets of resistors from Radio shack for $0.99 each. One needs to be 2.2K ohm and the other 10K ohm. If you take the 2.2K and connect it in parallel with a 10K, the result is 1.8K. Radio shack doesn't seem to sell a 1.8K value. You can also go to any electronic supply shop to buy it.

<a href="http://www.radioshack.com/product.asp?catalog%5Fname=CTLG&category%5Fname=CTLG%5F010%5F001%5F001%5 F002&product%5Fid=271%2D1325" target="_blank">http://www.radioshack.com/product.asp?catalog%5Fname=CTLG&category%5Fname=CTLG%5F010%5F001%5F001%5 F002&product%5Fid=271%2D1325</a>

<a href="http://www.radioshack.com/product.asp?catalog%5Fname=CTLG&category%5Fname=CTLG%5F010%5F001%5F001%5 F002&product%5Fid=271%2D1335" target="_blank">http://www.radioshack.com/product.asp?catalog%5Fname=CTLG&category%5Fname=CTLG%5F010%5F001%5F001%5 F002&product%5Fid=271%2D1335</a>

RJP 951

Is this "impedance adapter" the factory original version of the part you made?

<img src="http://boards.rennlist.com/upload/impedanceadapter.jpg" alt=" - " />

Ron

Danno

Remember also the impedance adaptor works differently between the 24-pin and 28-pin DMEs. It has to be used along with the region-coding plug and the combinations do not select the same maps between the 24-pin & 28-pin DMEs. Personally, I think selecting different maps to yield driveability improvements is solving the symptoms, not the problem.

Ron, on your chips, all the fuel maps are the same, so it will make no difference selecting a different one. You will however pick the ignition maps for race-gas only. Don't do this with street-gas in the car. Send me an email and we can talk about some fine-tuning.

coolhand

To connect the resistor do you have to splice into the wires, and do you do both the wires?

awilson40

nope...
small, unisolated 'butt splice connectors' from radio shack will plug into the factory connector. I soldered the connectors to the resistor and pluged into the factory connector.
Or you could cut the connector off the altitude switch and use that.

coolhand

Do you put each end of the connector into each side of the connector? just trying to make sure I understand this. Thanks

awilson40

OK...I'm trying to think of another way to explane this.... You unplug the altitude switch at the white plastic connector...let that part hang, the altitude switch is now and forever will be disconnected <img border="0" title="" alt="[Wink]" src="wink.gif" /> Then ....where the altitude switch WAS plugged into, you connect a 1.8 k ohm resistor, one side of the resistor goes to one wire, the other side of the resistor goes to the other wire. Thats it <img border="0" title="" alt="[Wink]" src="wink.gif" /> Danno mentioned that the older 951's wont select another fuel map by doing this, however, the electrical prints do show this 'impedance plug' for all years. BTW...Impedance is just another way to say resistance.

RJP 951

I haven't messed with the altitude sensor yet, but today, just for the heck of it, I disconnected the O2 sensor, and my part-throttle hesitation problem is completely gone!

I have GURU chips, so having the O2 disconnected didn't seem to be a problem like it would with the stock KLR chip [EDIT: i.e., no 1.2-bar boost limit in limp mode]. It didn't run excessively rich from what I could tell (no black smoke, anyway), but since the O2 was disconnected I had no signal for my A/F ratio gauge.

I had understood that the O2 sensor input was only used at idle or maybe just off-idle. Does anyone know differently?

Any thoughts about what's going on? Should I leave the O2 disconnected?

Thanks
Ron

awilson40

I have still been trying to work on this issue. I just replaced the 'J' boot due to its age and cleaned the intercooler. I've pressurized the intake several times and no leaks can be found. I installed an AutoMeter AFM gauge and noticed that the DME keeps the system in 'closed loop' while moderatly accelerating...thats when I notice the hesitation, as soon as it drops out of closed loop, the hesitation stops. So with the O2 sensor disconnected, its in open loop by default, hense no hesitation. I tend to believe that the DME programming should drop out of closed loop earlier. I connected a small vacuum switch in series with the 1.8k resistor and at 4-5 in /hg it will switch to ROW maps and at cruise, will run USA maps with the O2 sensor. It works pretty well. I have replaced every sensor except the speed and reff sensors, replaced vac hoses, eliminated the veturi tube and Cycling Valve, replaced BOV,TPS,AFM,KLR,Jboot and still have the problem on full USA maps. I have even plugged the connections for the Brake vac, emissions vac and crankcase vent AT the JBoot for a test, and it still had the same bit of hesitation. Its not bad, but is noticible. My best 'Fix' is to run the ROW maps via the vacuum switch.

silicondigital

Why not run ROW maps all the time?

RJP 951

I've noticed that my A/F ratio gauge gets quite warm to the touch (the glass on the face). I never thought much of it until I disconnected the O2 sensor yesterday and noted the car ran much better.

The gauge is one of those 10-LED units. Has anyone else noted their's being very warm?

Ron

awilson40

I'm just trying not to damage the cat. If I ever get around to gutting the cat then I probably will run the ROW maps.

Mledbetter

</font><blockquote><font size="1" face="Verdana,Tahoma,Helvetica">quote:</font><hr /><font size="2" face="Verdana,Tahoma,Helvetica">Originally posted by RJP 951:
<strong>I've noticed that my A/F ratio gauge gets quite warm to the touch (the glass on the face). I never thought much of it until I disconnected the O2 sensor yesterday and noted the car ran much better.

The gauge is one of those 10-LED units. Has anyone else noted their's being very warm?

Ron</strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Helvetica">What happens when you run the O2 sensor connected, without the meter in line?

-Matt

silicondigital

Ive measured and those A/F gauges dont draw anything noticeable, a handheld voltimeter will drain a LOT more. Also who cares about the cat that is 15 years old anyway? Just run ROW maps all the time and spend 50$ to have a glasspack or something welded in your CAT location like i did. (if you ever even want to)