MAF failure symptoms, diagnostics

[nvrstuk]

Well, I bought and installed an identical Bosch O2 sensor for the DS to match the one I put in yesterday.

I reloaded the latest tune, went for another test drive and now both sides when monitoring my laptop when driving are reading much closer to the same numbers.

I'll drive it again tomorrow to test it again. Then back in a week to try it all again.

Sent Garry 4 more datalogs from this afternoons drive. Hopefully he'll be able to tune it up...

 

[Madgyver]

always intrigued reading your posts Brian..
keeps me aware of what to expect going to an expensive efi system..
im still old school efi..

 

[nvrstuk]

Yeah Mad- I ran the Qjet until I couldn't anymore-seriously.

I ran Holley Projection in the early "90s then Qjet for 3 decades.

I think I'm close to being back to 100%.. No chance to drive it this morning.

Hope I'm back. If this was a corrupt tune it won't be a problem once a permanent chip is burned instead of running a temporary tune.

 

[lars]

Did you ever try pulling codes?

 

[jerry]

Did you ever try pulling codes?

Having played the "why is my eec-iv running like crap" on my Mustang (88, CA car = MAF) That was going to be my next comment.

https://www.fordtruckzone.com/threa...v-system-without-using-a-code-scanner.659319/

looks like the right procedure. I also believe you can use your VOM (an analog might be easier to deciper) vs a test light.

When I bought my Mustang a few years ago, I also picked up a SnapOn MT2500 with the right cartridges / connectors for the car. These seem to be fairly affordable and seem to have decent diagnostic capabilities.

Anyway, it's more than paid for itself. A couple of things it's caught - the time I didn't screw the O2 sensor all the way in (got distracted while replacing), and catching a air injection valve issue pre smog check.

 

[nvrstuk]

Ii have not pulled codes yet.

OBD1 code lights dont always flash when there is a problem so pulling codes with the old paperclip is what I need to do next.

I'll try it before I load the new tune on Sunday. Thx for reminding me.

 

[76Broncofromhell]

Dude, stop throwing parts at this thing!

You could have purchased three copies of Binary Editor and fixed the problem for all the unnecessary parts you've purchased.

You have a Quarterhorse - you need to get a reading of the ECU and see what major parameters have changed. I personally use the QH for tuning only and once that is all said and done, burn a J3 chip (which is solid state) for a permanent tune.

Fuel is calculated from a couple main inputs and some multipliers (temp, altitude, etc) on EEC-IV - Air (kg/hr), RPM, load, CID, Air intake volume. Standard EEC-IV KAMRFs can move about 12% in either direction to adapt to sensor tolerances or engine changes. If your base tune is lost and you don't have a default air mass table entered, you will run super lean.

If you inadvertently cleared the memory of the QH that could be the problem - or if you inadvertently triggered the tune switch function, that could also be the problem. You won't know until you plug into the QH. Anything else is wasting money and time.

 

[nvrstuk]

DUDE- lol

I haven't been "throwing parts" at this thing. Two O2 sensors that were submerged not that long AND were not reading even close to evenly when all other possible checks for having one bank running extremely lean AFTER the tuner said the O2 sensor was commanding a lean mixture, then I replaced them.

I replaced the 2 sensors that were recommended due to wear and inaccurate readings (at least one was) by my tuner.

I also think the tune was corrupted somehow amd yes, I need to get the tuning dialed in perfectly then burn a permanent chip like you said.

I just need to get some more dialing in on a tune before committing to a chip that is more or less permanent.

I am definitely a Qtrhorse beginner. I dont do any tuning but Garry is going to show me how to dial in my cold start and high altitude/high temp statting problems. Soon, so I can get a permament chip burned so this can be done.

Thanks for the info.

 

[nvrstuk]

Ran codes.

Get 1, then 5.

15 which means KAM right?

Only other flashes is:
1 light flash every 4 seconds 5 times in a row

 

[nvrstuk]

Loaded the newest tune with some slight fuel changes and kept close track on both narrow band O2 readings seem close enough I can't read one, look at the other and then go back to the first one and see any real difference.

Sent another data log back.

I'm going to work with getting some data logging and new tunes downloaded so when I get back from about 200 full throttle assaults at some sand dunes I'll be dialed in!


Put another 50 + miles on it this am. Seems to be running fine. My wide band reads lean at times when the narrow band sensors seem to be reading just perfect when reading data direct off Binary Editor when driving.

Maybe my wide band got a little wet also?? No idea. Wasn't sitting in water w/o the engine running so no water in the pipe. It did die for 3 days after the "water incident" then mysteriously came back to life for the past 2 months without a hiccup.

 

[lars]

Loaded the newest tune with some slight fuel changes and kept close track on both narrow band O2 readings seem close enough I can't read one, look at the other and then go back to the first one and see any real difference.

Sent another data log back.

I'm going to work with getting some data logging and new tunes downloaded so when I get back from about 200 full throttle assaults at some sand dunes I'll be dialed in!


Put another 50 + miles on it this am. Seems to be running fine. My wide band reads lean at times when the narrow band sensors seem to be reading just perfect when reading data direct off Binary Editor when driving.

Maybe my wide band got a little wet also?? No idea. Wasn't sitting in water w/o the engine running so no water in the pipe. It did die for 3 days after the "water incident" then mysteriously came back to life for the past 2 months without a hiccup.

Which wideband (manufacturer)? I have an Innovate, it requires occasional recalibration according to the instructions that came with it, along with an initial calibration.

 

[nvrstuk]

Autometer for all my gauges.

For some reason I wanted uniformity of guage style, color & type so I went with all one brand. Never do that for drivetrain or engine parts tho!! lol

No calibration needed.

 

[nvrstuk]

I think this is done. I think I had two issues. One- Qtrhorse tune (NOT a permanent chip/tune- important to know I'm running a temporary setup) Two- O2 sensor was dying.

I'm burning fuel like an ocean going freighter testing new tunes Garry has sent me.

 

[KyleQ]

Good deal, I was curious on what may have happened.

My Gary tuned GT40 headed 351w ran great but I was afraid of stuff like this when I wanted to double the horsepower so I went with a far simpler TBI setup with easily readable out input and adjustable inputs.

 

[nvrstuk]

I can understand wanting simpler.

My concern was over the counter parts and winter fun. Only thing not over the counter for me will be my chip when I get it burned. They have a fraction of a single percent failure rate.

For me, TBI isn't the best option for the snow, humidty and issues with freezing up. Not common but it happens at 6,000 ft when wheeling. This is why I went SEFI.