2G Air/fuel ratio questions

[arabeclipse]

I looked at the similar threads first, and found nothing to what I am looking for.

Anyway, I finally got smart and got myself an AEM UEGO wideband. I'm still on a stock turbo and injectors (til winter ends) and I'm tuning with a GM MAF and MAF Translator.

From what I understand, I'm supposed to see 14.7 at idle. I'm seeing between 14.3 AFR at idle on a warm engine. I tried to lean it out a bit to 14.7 and it won't budge. Cruising I also see 14.3-14.5, and in boost (not WOT) at about 10psi, the AFR is still at 14.7ish. I haven't tried WOT yet..I'm afraid to until I see what's up.

Something doesn't sound right. 14.7 in boost seems way too lean. I'm just wondering what I should be seeing on a basically stock car during idle, cruise, in boost, and WOT. I'm also getting like 17mpg and I go easy on the car.

Also, for idle, cruise, and WOT, what should i see with a s16g (15psi) and 560cc injectors? (for my future reference to avoid another thread).

 

[92AWDHX40]

Stock car you shouldn't be lean what are the settings on MAFT.

 

[5150DSM]

14.7 at idle, 14.7 to slightly leaner at cruise, 11.2-11.5 at WOT as a general rule of thumb. Every car will be different and need slight adjustments around the specific load points to run at optimal/safe levels. Unfortunately, the MAF translator basically makes you fight the stock settings over and over, especially at WOT. At WOT the stock ECM is trying for 9.5-10:1 and by the time you lean the translator out enough to get closer to 11, your timing is going through the roof. The MAF translator is good for what it is but your tune will always be somewhat compromised.

 

[ibreakmytsi]

My MAFT is setup way different than what it should be just to make the car idle like it should and perform the way it should. Try changing your settings around. I have a 3" MAF but had to set it up on the 3.5" setting.

 

[arabeclipse]

Stock car you shouldn't be lean what are the settings on MAFT.

Version 2.X Translator is set to 3.5" sensor. It runs better this way. I also have the 3rd pin switch up to richen up start up, which makes a cold engine 14.7, warm engine 14.3.

Aux: 4
Base: 2
Idle: 2
Mid: 0
WOT: E or F I can't remember

My car pulls like a Clydesdale with the WOT knob E/F. If I richen the setting, it drives like ass in boost.

I just drove the car again and and cruising is at 14.2, idle 14.3. I didn't drive in boost because its snowing a lot.

NO BOOST LEAKS either.

 

[92AWDHX40]

I had the maf also had a pocket logger it was OK then sold it all and got link much easier to work with.

 

[arabeclipse]

I had the maf also had a pocket logger it was OK then sold it all and got link much easier to work with.

Sadly, no more pocket loggers. And link is def out of the financial question.

 

[project98dsm]

Is a SAFC too far out of reach? i don't know of too many people using a maft to tune with. I'd hunt around for a SAFC, zero out everything on the MAFT, and use the SAFC to tune with. If Link is out of the question, definitely at least TRY to go that route.

 

[gsxnate99]

Translators are horrible for tuning. If you can't dsmlink then I would pickup a safc and just zero out the translator. Check ## Afr's and start taking fuel out where you need to with the safc. You can probably find a couple safc's for cheap. I think I even have a few laying around from past cars! Hope this helps

 

[arabeclipse]

Translators are horrible for tuning. If you can't dsmlink then I would pickup a safc and just zero out the translator. Check ## Afr's and start taking fuel out where you need to with the safc. You can probably find a couple safc's for cheap. I think I even have a few laying around from past cars! Hope this helps

PM me so we can talk about that. This maft is pissing me off. I can't lean out my cruising afr's and I can't richen up WOT....everytime I'm in boost my timing gets pulled now.

 

[clipto]

Do you have an eprom ecu, have you checked? You can get burned chips for decent price there people all around like my1gdsm that can get you setup good tune and sent to you in the mail. I hate maft and safc but if you don't have a choice and trust me I hate saying this but safc is little better. But in the end they both suck becuase you can lean it out and what not but who knows whats really going on in the motor. Timing maps going to be crummy and what not. On a burn chip can get knock gauge on dash, 2 step, all same stuff really as ecmlink but half the price.

 

[arabeclipse]

Do you have an eprom ecu, have you checked? You can get burned chips for decent price there people all around like my1gdsm that can get you setup good tune and sent to you in the mail. I hate maft and safc but if you don't have a choice and trust me I hate saying this but safc is little better. But in the end they both suck becuase you can lean it out and what not but who knows whats really going on in the motor. Timing maps going to be crummy and what not. On a burn chip can get knock gauge on dash, 2 step, all same stuff really as ecmlink but half the price.

My car's manufactured date is April 1995. I am pretty sure that's after the EPROM ecu.

Now I hate translators I wish I never spent $200 on this crap. No matter how much I "richen" or "lean out" there's no changes to the afr's. it wasn't doing this til I installed the wideband and I think that's what's pulling my timing.

 

[CAFIFTY]

If your car has a stock ECU it sounds like it is working correctly. OEMs only go into fuel enrichment for a handful of things (Power enrichment, piston proctection, catalysis proctection, and some diagnostics). So basically unless you are 90-100% throttle you should be in the 14.7:1 (1 lambda/equivalence ratio)range. OEMs do switch the AF ratio back and forth around 14.7 to get the cat happy (it likes the additional and subtraction of oxygen) but its pretty minor (max of 1% changes). This is why they can run narrow band sensors. I am rambling now, sorry.

 

[ibreakmytsi]

I had this type of problem with my translator as well. Make sure your rpm signal wire is hooked up correctly. Also. I had to start over on mine after a frustrating couple days of testing.
Zero it all out and start over. Sometimes it's a fresh start that helps

 

[arabeclipse]

I had this type of problem with my translator as well. Make sure your rpm signal wire is hooked up correctly. Also. I had to start over on mine after a frustrating couple days of testing.
Zero it all out and start over. Sometimes it's a fresh start that helps

I didn't have that wire hooked up. I did connect it and I did some tuning. Car's running better but still isn't perfect for me. Fuel cut at 11psi on stock turbo and injectors.

 

[clipto]

I didn't have that wire hooked up. I did connect it and I did some tuning. Car's running better but still isn't perfect for me. Fuel cut at 11psi on stock turbo and injectors.

Whats the a/f ratio when your hitting 11 psi. Also what spark plug and gap are u running?

 

[GSTurbo1]

while cruising it is ok to be in 13's 14's but as soon as you start boosting you need to be on the way to 11's.

 

[ariman]

Hi.
i have 1g talon and the last weekend i installed a maft with 3" GM and scanmaster3
now here are my questions
What values should I see in O2 trim at idle?, now i see 98-105, O2 .2 to .9 volts
What values should I see in o2 trim at 50% tps and 8 psi?, now see 140-160, O2 .75 volts

What values should I see in o2 trim at wot and 14 psi?, now see 120-130, O2 .82 volts

turbo stock and injector stock
Thanks

 

[Cdc1221]

Your o2 values mean squat in open loop, which is past around 20% throttle. Fuel trims and o2 sensor readings are strictly for fuel economy in cruising conditions. The best you can do with a piggyback and no wb o2 is simply get your stft as close to 100 as possible, and zero the mid and wot ranges out

 

[arabeclipse]

Whats the a/f ratio when your hitting 11 psi. Also what spark plug and gap are u running?

They show 14.3-14.5 at 11psi and I have BPR6ES plugs gapped at .28

BUT, there's a wire from my wideband that connects to the front o2 sensor wire on the ecu. I had that connected, but then when I disconnected it, the car runs like nothing ever happened.

But my afrs are still as they are.

Your o2 values mean squat in open loop, which is past around 20% throttle. Fuel trims and o2 sensor readings are strictly for fuel economy in cruising conditions. The best you can do with a piggyback and no wb o2 is simply get your stft as close to 100 as possible, and zero the mid and wot ranges out

Yea I connected the white wire to the rpm wire that sits in that connector behind the injectors for rpm tuning. idle and MID are zeroed out, and I have yet to zero out WOT because I'm still getting fuel cut at 11ish psi.

That wire from the wb that goes to the front o2 sensor is what caused my car to run like ass. Now it runs fine, but my afrs are like i said, reading weird.

while cruising it is ok to be in 13's 14's but as soon as you start boosting you need to be on the way to 11's.

Cruising jumps around from 13.9 to 14.9 and sometimes it'll spike really quickly to the 16s. but I haven't tried WOT cause of this weird fuel cut.