Continuing from this post:

https://www.thirdgen.org/techbb2/sho...hreadid=277216

I moved the WBO2 sensor to the stock location tonight. I still have the same results. I did notice that the response time was quicker.
I am still getting Vout readings of about 3.08-2.9 volts.
What gives?
I eliminated the possibility of an exhaust leak causing this by relocating it to the stock location. The headers seal tight at the head.

I am confident in my soldering skills and do not doubt them. I built the DIY WB board exactly like it says. I do not understand.

I get the expected 2.5-2.6 Vout during warmup, but after that it is shot.
When I ordered my parts I accidently ordered only one LM2902 chip so I replaced the chips with LM324A's because I could get these locally.

I went through the checkout and I did have have a problem with steps 34 and 36. The voltage wouldn't drop. I replaced the U2 chip with the extra LM2902 chip and the voltage started dropping. It will take longer than 2 minutes though, but it does drop now. I now have 1 LM2902 and 1 LM324A chip in my controller, will this cause problems?
I also noticed during my research that a cap should be installed on D5, so I installed a .1uf ceramic cap accross the outter most legs. I have a 10 ohm res. accross the monster res.
These are the only mods to the design.

I am to the point where I am ready to throw the whole damn thing in the trash!!!

Someone Please tell me I didn't waste my time and money!!!

I am ready to go buy an Innovative unit now.

 

I forgot to mention I was using my AutoProm and changing my injector const. around to get an extreme global AFR change.
I went from 15-35 and the lowest Vout I saw was 2.7!!!
My eyes were watering and yet it still said I was running lean!!!

 

OK, you didn't waste your time and money. Just set it aside for a day or so. The LM324 will work, it just isn't rated for extreme temperatures as found in automobiles.

The step 34 needs to check out:

Measure the voltage at U2 pin 1. Verify .45 volts (+- 2%, 0.441 to 0.459 V).

The others where the voltage slowly drops or increases may or may not work.

If push comes to shove I'll take a look at it for you.

RBob.

 

Thanks for your help RBob. I will keep you posted.

 

I hate to be contrary, but I can't agree less with your topic title.

I found that the DIY WB, built correctly, works as advertised. Mine has been in use for
more than 3 years now with no problems whatsoever.

IMHO you need to go over your work again - the fault is not in the kit or the design.


Some pix of my installation are here - perhaps they may help:

http://www.corvetteforum.net/c4/doctorj/carwb.htm

 

I am sure the design works well when built properly. I am just frustrated.
I also entitled this thread My Diy Wb is a POS because I am sure the design is great but mine isn't. I don't want to tarnish the project name, I am grateful that the project was succesful. I posted pics of my design at
www.jons91z28.zoomshare.com

 

Here are my checks RBob, tell me what you think.

Measure the voltage at U2 pin 1. Verify .45 volts
I HAD >>>> .48 v
Measure the voltage at U3 pin 1. Verify ~ 4 volts.
I HAD >>>> 3.89 v (LITTLE LOW)

Open the switch.

Measure the voltage at U2 pin 8. Verify ~2.7 volts.
I HAD >>>> 2.69 v
Keeping the DVM on U2 pin 8 close the switch. The voltage will slowly drop. It will take ~ 2 minutes with the voltage reaching ~ -3.4 v.
I HAD >>>> 2.69 v------>2.63 v AFTER 2 MIN.

Open the switch.

Measure the voltage at J6, Ip. Verify ~ 0 volts (+- .1 v)
I HAD >>>> -.06 v
Close the switch.
The voltage should go to ~ -2.7 volts and slowly increase to ~ 2.4 volts.
I HAD >>>> -2.58 v
INCREASED SLIGHTLY FASTER THAN PREV. STEP DECREASE

The following test verifies the pump drive (Ip) and the Vout circuitry. A resistor is required: anything between 100 and 510 ohms will suffice.

I USED 100 OHM

Open the switch (off).

Place a jumper between J9 and J10 (CalR).
Either solder a wire in or use jumper clips.

Place the above mentioned resistor between J6 (Ip) and J7 (Ip/Vs Gnd).

Connect the DVM ground to J12, ground.


Measure the voltage at J8 (Vout). Verify ~2.5 volts
I HAD >>>> 2.48 v

Close the switch (on).

Upon closing the switch the voltage at J8 will drop. After a pause the voltage will slowly increase. It will take approximately 1 minute & 15 seconds for the voltage to reach maximum.

I HAD >>>> 1.38 v WITH NO INCREASE

 

Here is a link to a pic of the sensor.
This is after 20 min. of run time.

http://www.jons91z28.zoomshare.com/index.shtml/Projects

 

This is close, but not close enough. In this case I think it may point to a bigger problem. PM sent.

RBob.