my first HPtuner scans

[boomofdoom88]

Today I did some driving and scanning with HPtuners. Is it normal to have absolutely zero KR and also my map kpa stayed at 10 kpa both key on and running. Maybe bad sensors or I have a huge vacuum leak? It did exhibit a slight stumble at tip in. This is on a 3500 with a 3400 upper/tb and 28 lb injectors running at 62 psi. So far I think I have the fuel injector flow set right and I copied in a 3500 ve table.

I used the default configuration in the scanner app. Is there any special configuration needed for our setups?

thanks in advance and sorry I have no datalogs right now. I'm on my linux desktop, my laptop is with the car 40 miles from here

[SappySE107]

Gee's gauge config.cfg

This is a good start. I haven't had a chance to update my article. When you get a chance, post your file and log.

[Schmieder]

Congrats, it is a long but fun road as long as you respect the responsibility you now have over your cars engine.

If the Map isn't changing from key on/engine off then idling, something is wrong. It you have a vac leak I'de expect the Map to read 98-100 kPa at key on. It should always read atmosphere pressure when not running.

No KR is a good thing!

Are you using a MAF sensor?

First things first, fix the MAP sensor problem. Because if that isn't operating properly, everything you tune will be flawed.

[boomofdoom88]

Yes I was using the Maf Sensor. I'm not gonna do anymore tuning until I get my headers,downpipe and exhaust finished along with the lc-1 wideband for the front o2. Right now I have the rear o2 deleted just to see if it was throwing codes. Gonna re-enable it after I buy a new rear o2 sensor and have a bung welded into the exhaust

Heres my latest tune and log

[Schmieder]

Keep in mind I am not a seasoned mechanic. I'm just a professional of my own car, lol. But we have similar vehicles and tuning is something I've come to love. Take my advise with a grain of salt.

Well, you can still do some tuning before you are done putting on mods, thats different. I see your PCM is pulling A LOT of fuel, better rich then lean so you got that going for you atm. But it must run pig rich at WOT.

It appears you are running the richest at idle conditions. I am wondering if your Fuel Pressure Regulator is even hooked up to vacuum or is there a massive vac leak by the FPR? Which prevents the FPR from reducing fuel line pressure under vacuum (idle), causing the injectors to push more fuel then what the PCM knows them as.

Your MAP reading 10kPa is a mystery to me....hopefully someone else can chime in. Is it the stock MAP Sensor or did you put a new one in? Maybe you have a short of some sort regarding the MAP because I think, not sure, but do believe 10 kPa is the lowest possible reading the PCM will accept. Suppose you are over volting the sensor or the sensor wire? I'de look into the wiring as well and make sure it's proper.

You might want to at least stabilize your fuel trims some. Find out why they are so rich at idle cause the PCM is maxing out the (-) trims



EDIT: I see you unchecked the rear O2 sensor from the DTC list. If you want to pass emissions leave it checked but keep it 3- Report no error. This way the inspection station will see the system is active (checked) but reporting no errors meaning all is as it should be. But if you leave it unchecked they will know and fail the emissions test. That is if your State requires a PCM check, most do.

This is just opinion but, you are getting some KR at Throttle 55-60% but your PE is set to kick in at 70%+ Maybe you should set PE to kick in at 50% throttle. Because your engine is still attempting to stay stoich (14.7) at 60% throttle when you probably want a more power producing AFR like 12.5-13.2

I think running 14.7 AFR at 50-60 Throttle is causing that KR to occur. Your spark is a strong degree but not abnormal.


Find out why you are running so rich at idle and low throttle!!!

[boomofdoom88]

Keep in mind I am not a seasoned mechanic. I'm just a professional of my own car, lol. But we have similar vehicles and tuning is something I've come to love. Take my advise with a grain of salt.

Well, you can still do some tuning before you are done putting on mods, thats different. I see your PCM is pulling A LOT of fuel, better rich then lean so you got that going for you atm. But it must run pig rich at WOT.

It appears you are running the richest at idle conditions. I am wondering if your Fuel Pressure Regulator is even hooked up to vacuum or is there a massive vac leak by the FPR? Which prevents the FPR from reducing fuel line pressure under vacuum (idle), causing the injectors to push more fuel then what the PCM knows them as.

Your MAP reading 10kPa is a mystery to me....hopefully someone else can chime in. Is it the stock MAP Sensor or did you put a new one in? Maybe you have a short of some sort regarding the MAP because I think, not sure, but do believe 10 kPa is the lowest possible reading the PCM will accept. Suppose you are over volting the sensor or the sensor wire? I'de look into the wiring as well and make sure it's proper.

You might want to at least stabilize your fuel trims some. Find out why they are so rich at idle cause the PCM is maxing out the (-) trims



EDIT: I see you unchecked the rear O2 sensor from the DTC list. If you want to pass emissions leave it checked but keep it 3- Report no error. This way the inspection station will see the system is active (checked) but reporting no errors meaning all is as it should be. But if you leave it unchecked they will know and fail the emissions test. That is if your State requires a PCM check, most do.

This is just opinion but, you are getting some KR at Throttle 55-60% but your PE is set to kick in at 70%+ Maybe you should set PE to kick in at 50% throttle. Because your engine is still attempting to stay stoich (14.7) at 60% throttle when you probably want a more power producing AFR like 12.5-13.2

I think running 14.7 AFR at 50-60 Throttle is causing that KR to occur. Your spark is a strong degree but not abnormal.


Find out why you are running so rich at idle and low throttle!!!

Thanks for the help man. I will start with figuring out my map sensor problem. I'd say its probably just bad. it has 100,000 miles on it. Then I think im gonna get some new vacuum lines and check and see if I have a leak somewhere. I had checked the fpr at idle with a guage, not sure why I didn't check it under throttle. I made those changes to my pcm tune and I will apply next time I work on the car.

thanks again.

[Schmieder]

Just remember, no matter how simple or innocent a change to the PCM seems, always pay attention to the engine and especially know what your AFR's are. If you don't have a wideband, at least make sure the narrowband oxygen sensor stays around 800-900mv during WOT. Anything that stays well below 450mv longer then the normal switching speed will indicate a serious fueling problem.

In other words, always make sure the engine sn't going lean after any changes to the PCM. I doubt it would if you just change PE TPS variables, but it is a good habit to have while tuning.

Always store the original, unchanged PCM file somewhere safe in multiple places. Every time you make a change, save it as a new file, don't over write. This way if the changes don't work out you can revert back. It also serves as a historical referrence which can become useful in diagnostics should you ever need them.

Here is a guide I used when I was new to tuning. It isn't exactly like your PCM but it is really darn close and it will really key you in to the basic run down. Digest it well and you will have a considerable greater knowledge about tuning your ride.

LINK TO PDF

[boomofdoom88]

yeah I have a wideband which is why I wont be making any drastic changes to the tune until I have it hooked up. I got a new map installed, turns out the original wasnt staying plugged in.

Got a new scan today but I forgot to save it lol

[pocket-rocket]

The tab on the 91's MAP was broke off and the pigtail wouldn't stay in so I used silicone to hold it in. I just ran a small bead around the weather-pack seal and it never fell out.

[Schmieder]

yeah I have a wideband which is why I wont be making any drastic changes to the tune until I have it hooked up. I got a new map installed, turns out the original wasnt staying plugged in.

Got a new scan today but I forgot to save it lol

I wonder how much of an effect the bad MAP had on your fueling. That's good you have a wideband, I can't imagine trying to tune w/o one.

Some people are against running Open Loop but I liked it. It has it's challenges but it has it's pay offs too. Like leaner cruising, easier accel/decel control, better WOT control and idle.

After many logs I was able to chart where the car ramped into boost. This way I was able to have 12.5AFR at WOT onset, slide to 12.0-11.9 during spool up and then hit 11.6 when boost kicked in and slides to 11.4 while under higher boost.

The regions when the throttle slammed shut when previously under boost were skewed even more so to keep the decel fueling happy.

After MANY variable throttle revs from idle, I charted the path and built the fueling table to hit 13.5 immediately and slide to the region it was heading towards (cruise, power, boost).

My wideband would not jump around, it was smooth and went exactly where I wanted it to go (w/ exception of accel enrichment tuning). When you get to tuning Accel Enrichment after all the rest is tuned up, I'll help you tune that up. Everyone said it was something that was a blind shot procedure that needs refining over time. I found a mathematical way to bring it to a fine tune. Though it is really complicated unless you know how to use Excel.

I'll dig up my Excel doc for the Accel Tuning. I might have lost it (PC wipe) but I will be tuning my ride again soon. So I'll have to rebuild the Excel Doc and then I'll share it.

Mr.Rocket, you will love that. Even though your OBD1, it is still a niffty method.

It relies on 3 logs. The second log we blindly adjust the Accel Enrichment, the third the same. It takes the differences in the tables changes and the results then determines how much further/less to adjust the tables to hit center. It relies on the AFR spikes and the intenisty of during ACCEL to determine the proper values to input.

The neat thing is using the formula will continually refine the ACCEL tables. Like dividing a number in half, it will never end. But only a few times required to be practically in between 0-1.

[boomofdoom88]

my latest scan. Im still learning alot of this HPtuner wizardry lol. Is there anyway to input a custom PID to get an a/f ratio for the narrow band o2 till I get my wideband setup?