RRT vette

I would have posted this in Scan and Tune, but not enough traffic. I got the TunerPro RT running a few days ago (thanks to Craig Moates and Rick Lambert). I connected it to my ALDL and started the car. I let it idle for about 2-3 minutes and watched the scan in progress. I jotted down a few numbers and wanted to post them to confirm my problem. Once I put the vette in gear and started down the road the scan stopped and I would have to pull over to start it back, but would only do a little and stop again. I haven't had time to try it again but will keep the posting up when I get more info.

86E vette stock, no precats, hollowed cat, Dynomax mufflers, 24 LB injectors, stock FPR runs at 40 psi vacuum connected. Will give more info if requested

Here are the numbers from idle:

MAF raw input 9
MAF 10.61g
TPS .55v
Target AFR 14.73
O2 sensor .5-.7v (varied ever sec)
INT 128 (idle) 95 (when the scan worked driving)
BLM 108
Ins Base Pulse With 1.6 msec (varied every sec)
IAC 38 steps
Spark adv 23.91
Spark adv rel to ref pulse 18.2
Knock count 2 (I think came from start up)
Knock retard 0
MAP 1.86

No codes shown
I'm running rich in all phases (open and closed) as you can tell, this is a scan in open loop. I had posted a few weeks ago about a AFPR and Holley seemed to be the winner. I'm sure I will need to decrease fuel pressure and perhaps tune my chip for the injectors. The car starts and runs fine other than pig rich. Any suggestions?

Thanks in advance

tequilaboy

idle rpm? ( also target rpm )

your raw MAF and filtered MAF values look pretty high for idle compared to what I'm used to seeing unless you're idling > 900-1000 rpm or so. Maybe this is normal for an auto trans due to converter load ???

The elevated airflow is likely the cause of the extra enrichment. I would knock down the MAF calibration to get the blms in line.

which chip/ecm is this? the custom 86 tune or 88. Which broadcast code?

kopbet89c4

My car also runs in the rich side at idle with the BLMs at 120. When I'm on the throttle, its between 124 to 128. Its been running ok so far. Gets me to and from work reliably with a WOT pass at least once on the way.

Ray Quayle

DJ, I've been waiting for you to get this going. May I ask what .ads file you used? If in 160 baud mode, the 10K resistor will be in place and the idle will be 1000, which explains the MAF readings. Also there is much less data at 160 baud. I haven't been able to get TunerPro to connect at 8192 and they'll say that the 165 ECM with $32 mask won't do 8192, but Diacom does it. I can even get it into 8192 with Diacom and then switch to TunerPro and it will then connect in 8192. Just wanted to see if you had any luck with 8192 and TunerPro on your '86 (165/$32).

RRT vette

My idle was around 1000 rpm at first and then settled down to around 800-900 rpm after a minute or two. When I put in in drive and started moving the idle came down to around 650 rpm, but like I said it would stop scanning while driving. Seemed like when I went WOT I saw a lot of values go into red text (BLM, Int, maybe one or two more). This is with the stock 88 chip/ECM. After I get some more time to scan again and get comfortable with it I might switch the ECM's out again, just for sh**s and giggles. Target RPM was 650

Craig talked me through it pretty quickly. I think I'm in 8192 ALDL mode and I do remember seeing something about a 10k resistor. 1227165 ECM and code mask 6E .ads. I just looked back through the program and the 160 baud was not selected and it does say 8192 selected. Should I check the box beside 160 before I run the next scan?? Maybe some where in this I answered you last question, Ray. I will do a little more when time permits.

rick lambert

for some reason (ink) I can't print this, Your Maf at idle looks fine (7-12) Don't know why we both got a MAP reading, cause we don't have a MAP sensor-wierd. According to my friend Morley, the MAF Raw is kinda meaningless, he suggest stick to the Gms/sec, that has meaning.

Your BLMs (often referred to as "long term" fuel trim) will probably be better when you get your AFPR.

Since you're not pulling any timing, don't worry about the knocks.
Your 02 is doing what it is supposed to do.

Ray Quayle

DJ,
Thanks, but I'd forgotten you were running an '88 PROM. It is $32B and that seem fine in 8192 using the 6E ads as you've seen.

Thanks anyway.

rick lambert

Hey Ray, come back here maybe you can answer this part too. Why do you suppose both DJ and I got a MAP readout on our 86 and 87?
Even my 87 FSM talks about MAP, even gives a voltage reading, but there are no MAP sensors? I've read where MAP was used only in 84 I think, and then again on later models.

kopbet89c4

Could the "MAP" in MAF cars be the voltage at the MAF?

tequilaboy

Byte 29 is the MAT (manifold air temperature) voltage, incorrectly labelled as MAP in TunerProRT

rick lambert

Don't know I know the FSM in acronyms (did I spell that right?) talks about the MAP voltage being between 4-5 volts, but there is no MAP sensor, in MAF cars the ECM sources a voltage (4-6) volts to the MAF sensor, and that's as close of a correlation as I've seen. Yet it's funny both DJ and I have a MAP readout on our scanning.

Hey tequilaboy, thanks for the explanation...mabe someon should clue Mansur in on this!

RRT vette

Sorry guys, I haven't been very active on here today. I spent most of my day wheeling and dealing on a 06 F150 crewcab FX4. I had been wanting one for some time now and decided to break the bank. Yes, I don't have a MAP sensor and do have a MAT sensor. As stated, I guess the readings from the MAT are displayed in MAP readings. Everything seems to be o.k. except for the BLM's. I have a feeling, now, this will be a long process of getting the fuel trims right. I need to get some data while driving for a more complete scan. I will have to work for the next 5 days so it might take awhile.

Thanks for all the help so far.

Ray Quayle

Anyone using one of thes ads files will see this item unless you change it. tequilaboy is correct and really knows his stuff, way better than me when it comes to tuning. Byte 29 and 30 both refer to MAT. Byte 29 is the raw value and is multiplied by a scale factor to display actual volts. Byte 30 (the one actually listed as MAT in the 6E and 86-88_8192 ads files) is the Analog to Digital converted representation of this value in COUNTS that is bounced against a table to obtain temperature. So both MAT in Temp and MAP in Volts, as listed in TunerPro, from the 6E or 86-88_8192 ads files show the same data in different formats.

I'm not sure if Mark even supplied these ads files although they list Mark as the author. Anyone can hack these things up. So it may not hurt to inform him, but I just eliminated it. Go to ALDL Setup (F4), click the "Edit ALDL Datastream Definition" button, click the + to expand ALDL Sensor Data, scroll down and click "Manifold Absolute Pressure (MAP)", click the "Delete" button and then click the "Save Changes and Close" button. No more pesky MAP item.

rick lambert

That all makes sense Ray and Tequilaboy. What I'm curious about is why the FSM for an 87 actually references MAP and its voltage?of course there are no MAP sensors, that I don't understand unless they just used the same acronyms with explanations in the Driveability and Emmissions section for several years, since MAP was used in 84 and not again for many years, did they just get lazy and not eliminate it from this section?

RRT vette

I got a chance to use the scan again today. It is a little hard to document the scan while driving. The knock counts are a little high and the knock retard started increasing while driving from stop. These are the numbers after various driving conditions after I got back home from the post office. I had started a thread about a popping sound I keep hearing from the TB/plenum area at around 1700-2200 RPM, seems when I hear the noise the knock counts start piling up. Sorry, not much time now to discuss, my wife is on a rampage and we will be leaving for a few hours. I'll check back later, (I didn't double check spelling). Thanks


TPS....57v
Cool temp...208
Srtart up Cool temp...211
MAT...139
Voltage...13.9
FP voltage...13.6
engine RPM...750
N/V ratio...255 rpm/mph
MAF...8.1 g
MAF raw...7g
Load variable...50
Run time...930 sec

Target AFR...14.7
O2 sensor...7-9 mv (varies)
INT...127
BLM...108
Inj base with...1.5
Desired idle speed...675 rpm
IAC...36 steps

Spark adv...23.5 (varies close)
Spark adv relation...16.8 (varies close)
Knock count...142
MAP...3.14v
EGR...0 (goes to 100% + after throttle and driving)
ECCS...0 (goes to 80% + after driving)

RRT vette

Late entry: http://forums.corvetteforum.com/show....php?t=1404200

tequilaboy

You know that you can record the data to a log file/recording session by clicking on the red button and then review or export the data later, so you don't have to visually monitor while driving.

RRT vette

I did not know this. This will save a little headache, but I knew it could be done but not how. After viewing the scan in various driving conditions, I only can see where I am running pig rich. I need to confirm that the rotor is pointing at #1 cylinder TDC and purchase the AFPR. Why would I be getting so many knock counts while driving? I don't hear them other than the popping noise, but it will knock when the noise is not audible. Thanks

rick lambert

You probably need to re-check your timing and the wires on the ESC.

RRT vette

Will do.