Here's what's been done to the engine. I have a 305 TBI with 50mm tb with 55lb inj, an afpr, a bored edelbrock tbi intake to match the tb, LT1 cam and 1.6RR. My fuel press is at about 11psi and if it wasn't for the EBL i'm sure my car wouldn't be running because I have no tunning skills other than using the VE learn. So I failed the loaded reading HC and CO, and I failed the idle reading HC. The loaded HC standard here is 220 I had 385, and the CO standard is 1.2 I had 6.35. The idle reading HC standard is also 220 I had 324 and the CO standard is 1.2 I had .42 . The reason that i'm posting here is because I would like to know what if anything can I modify to get these numbers down. Just a little more background info I've had the EBL for about a year and a half. I passed emissions before, but that was before I did the 1.6rr and messed with the timing to get the car running. I also had to pay a guy $50 to tinker with the idle setting to get the car to pass that time. I know i'm giving you some random info. If you need to see something else let me know what, and i'll get it for you. Thanks Will

 

As an emission repair technician in Nevada I can tell you I have seen many GM TBI V-8's fail Hydrocarbon PPM's at idle. We also use 220 PPM as our standard; I believe CA is down to 110 PPM.

In most cases retarding the timing dramatically reduces HC's at idle. A simple test is too unplug the EST connector and watch the HC's drop(if you have access to a gas analyzer). Your CO's(mixture) are fine at idle.

As to 6.35% CO's at cruise....way too rich. Why? Are you in CL? O2 switching good? Could be MAP, CTS, etc....If you do not feel a miss at cruise the HC's at cruise may be a symptom of the high CO's.

How bout doing some data logging and post some cruise data; i.e. O2, BL, integrator info. Sorry, IM waiting for my EBL Flash to arrive so IM not familiar as to its protocol yet.

Robbie

 

The EBL can definately allow an engine that is running in a good state of tune to pass emissions with ease.



You don't mention headers of any form, but if you have headers a 3 wire heated 02 sensor is a MUST have to keep the oxygen sensor hot enough, especially at idle and low loading to function properly. If the 02 sensor starts to cool down the ECM will interpret this as running lean and pour on extra fuel.

 

Thanks you guys for the info. After changing a messed up CTS and MAP sensor I've gotten my readings at idle down well within limits. My loaded CO reading is good also. To answer Fast355 I don't have a wideband right now but I do have the hooker 2055 headers. I don't know what or how to wire a wide band O2 sensor to the EBL. If any body could give me some info on that or point me in the right direction I would appreciate it. Now back to the problem. My loaded HC reading is where I failed, my reading was 275 and the standard is 220. For this reading I'm on their test equipment I speed up to 30-35 mph and keep the car in the middle while they have their probes in my exhaust and they take their readings. So I went out and did some data logging. I kept my car in between 30-35 for this. However it seems that at their testing station it takes more throttle to maintain the vehicle at the appropriate speed. It's kind of like going up hill. I'm keeping the vehicle in 5th gear during the test also. I'm not quite sure where i'm going to need to improve. The only are that I could think of is in my SA table

 

There's more

 

This is the last of it.

 

I notice in first analysis you are not in CL and the NB02 sensor is showing rich.

Second and third shows you in CL and NB02 is switching. BLM is fine ECU is adding some fuel over 128.

Is the NB02 sensor cooling off and flipping OL? Not uncommon with headers. May need a heated unit. when I ran unheated it would take a long time to flip CL on a cool day but usually would stay CL unless I was cruising in 5th gear at low speeds.

 

Ok, so a heated O2 sensor. I tried doing a search on this and couldn't find any part numbers or application. If any one could give me the info on this I would appreciate it. It was rather cool the day I did the data log and since it's starting to cool off more here in Tucson I'm sure it'll be helpful. By the way, would this be something that will be plug and play or will some wiring or other fabrication or adjustments in tuning be required?

 

This is what a search turned up!
Longtubes?

Get a heated 02 Delco number is AFS-74

Than start working on things :-)

Your 02 will be erratic until then.

Even when still moving but cooling down they dont read right.

later
Jeremy

 

Ok so would I need a 12vdc power source for the heating element? but do I want it constantly heating up the NBO2? Would it be possible to wire up the heating element to the EBL and have it control the heating element? or if i'm going to be wiring all this up should I just find a wide band or 2 bar (not sure if it's the same) O2 sensor?

 

This is a guess but I believe the heated NB02 needs to be heated only when the engine is running meaning when the fuel pump is on.

There are a few that use the WB02 as a simulated NB02. I use the NB input to ECU and have a seperate stand alone WB with controller permanently installed w/o input to ECU. Eventually I will patch the A/F to ECU only to show in logs without affecting fueling.

 

Awesome thanks

 

Ive got heads, cam, intake, headers, etc... on the 305. I set EBL to run off the wideband only (wideband cruise, wideband idle, and decel) and passed with flying colors after trying to pass 4 other times trying to tune with WB and then go back to blm/int.

I occasionally go lean on hard acceleration from cruising because ive yet to perfect AE but other than that she runs like it came from the factory this way.