INNOVATE DLG1 Wideband O2 Oxygen Sensor Tuning Diagnostics Logging Air Fuel Ratio etc

[rgunlock]

Thanks for the response, and basically for making me aware of this tool and its usefulness. Humid or not, right now my idle after driving several miles (fully warmed up) is between 15 and 17 so I'm thinking some tweaking of the mixture is in order. I have such a strong fuel smell that I was just sure I was idling rich. But, then again I'm already at 15.1-15.4 at cruise so that seems to be good. Amazing what you can find out after a single drive with one of these gauges.

[Gregski]

Originally Posted by rgunlock

Thanks for the response, and basically for making me aware of this tool and its usefulness. Humid or not, right now my idle after driving several miles (fully warmed up) is between 15 and 17 so I'm thinking some tweaking of the mixture is in order. I have such a strong fuel smell that I was just sure I was idling rich. But, then again I'm already at 15.1-15.4 at cruise so that seems to be good. Amazing what you can find out after a single drive with one of these gauges.

before going twisting away your idle mixture screws please do the following:

1. check your timing, if its low like 10° bump it to 12° then test drive it, you may need to decrease your idle speed a bit to compensate for the higher RPMs, observe the gauge, then bump it to 14°, rinse, lather, repeat

2. check/adjust float levels before twisting the idle mixture screws

not preachin' or soap boxin' just honestly trying to help

[truckin 79]

Anyone else using a air/fuel gauge? I put in a previous thread that I have had trouble passing emissions in CO. I thought I fixed it with EGR replacement but that was wishful thinking. I took to a local garage and asked them to see if they could get it within limits to pass emissions. They charged me 100 bucks and said carb needs rebuilt. I just rebuilt carburetor and the guy says well then you need to buy another carb. I buy another carb rebuilt from Rockauto 260 and take to emissions station, I thought I felt a little improvement while driving truck. Well with new carb it failed even worse then old carb. I thought I would buy a A/F gauge and luckily Gregski has a good write up on install and tuning. I just wanted to know if people who had these gauges averaged the 14.7 or what readings were like. I bought a AER gauge from Ebay 170, I thought it was better then paying some mechanic who did not really care anyway.
Oh yeah thanks alot Gregski for all the great info on this and other thread. I think you should print out all these pages out and sell online as a how to book.

[Gregski]

Originally Posted by truckin 79

...I put in a previous thread that I have had trouble passing emissions in CO.

I am sorry to hear about your SMOG woes, living in California (pronounced Emission Constraint Capitol of the Globe) I feel your pain, though here vehicles like my truck 1975 and older are exempt thank god

couple tips if I may:

0. read the SMOG report, it tells you where you failed and how bad, I had a car that would pass emissions but fail some other thing like visual inspection or something cause a hose was missing, or some nonsense like that, how bad does it say you missed the cut off by?

1. check your timing with a timing light

2. do not SMOG a cold vehicle, take it for a nice 30 mile drive on the freeway on a day where the SMOG shop won't be busy, and then pull up right to their car port ready for a test

3. check your timing, is your coil good or bearly limping along

4. do not fall for any of that Sea Foam crap, if you feel like wasting your money on snake oils, please send the cash to me instead, ha ha

5. read your spark plugs, put in new ones, gap them properly, are you using an HEI distributor if so are the plugs gapped big like .045 or even .050

6. hey, have you checked your timing, ha ha

7. I change my oil and oil filter and air filter before smoking a gross poluter as well, every bit helps, plus it's just good overall maintenance

8. how old is your muffler, maybe a new $100 turbo one will help

Originally Posted by truckin 79

I just wanted to know if people who had these gauges averaged the 14.7 or what readings were like.

That is a great question, and as a newb we all chase that perfect stoic number, but as we get more experienced we realize tuning a bit richer is more realistic, so shoot for like 13.5. However remember there are three conditions and 14.7 is not acceptable for all of them.

1. idling at a red light (ok shoot for 14.7) but more likely be happy with 13.5, always safer for the engine to run richer than leaner, too lean can damage your engine

2. cruising on the freeway, acceptable range is 15.5(ish) as it does not take much horse power to keep the vehicle moving, something like 40 horse will do it

3. power, use the poor man's dyno for this, aka a nice hill on the freeway, with no heavy traffic around floor it up that hill and have a buddy watch that AFR gauge, for a chevy small block 11.5 AFR is a nice horse power pull

of course all these numbers are just a guide, your engine/truck may want to ebb and flow a bit differently

Originally Posted by truckin 79

Oh yeah thanks alot Gregski for all the great info on this and other thread. I think you should print out all these pages out and sell online as a how to book.

thank you so much, I appreciate that, I need to graduate to making videos, but I have the face for radio, ha ha

[truckin 79]

So still interested in anyone with familiarity with A/F on a Q-jet. I drive my 79 to the junkyard on weekends, not a daily driver. So truck usually starts right up after two cranks with choke down on cold morning A/F is about 12. As truck warms up on cold mornings going to junkyard about 35 miles (40 minutes one way)away I get 14-15 at stop lights and 16 A/F while cruising about 55-65 there. When I start the drive back home truck at stop lights hits about 16-17 A/F and while cruising at 55-65 hits about 17-18 sometimes gauge wont read how lean. If I step on gas it hits 13 but once out of gas I start getting 17-18 at cruise and idle. I am about 12 degress BTDC right now and seems to run okay, I am just worried that I am running to lean. The truck does not back fire or stumble while driving. On acceleration it kind of sounds like put-put-put out of the exhaust.

[rgunlock]

I haven't done any changes to my tune since my last posts. Was told by a knowledgeable source that with my GM Performance 350/290 I'd never be able to tune my Quadrajet so I'm happy with it unless I first change out the cam. Too much cam for too low of compression ratio. That said, I get 15-15.5 at cruise (1800-2000 RPM) and after the truck is totally warmed up it bounces around between 16-18 idling at ~800 RPM at lights. Much lower numbers when the choke is still involved. My base timing is at about 16 BTDC.

[Loco83]