Normal values

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Warnburt
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Joined: Sat Jan 30, 2016 8:03 pm

Normal values

Post by Warnburt » Sat Jan 30, 2016 8:59 pm

I have a gm tpi system from a 1986 camaro on my 1972 pickup (350 small block, rv cam and headers, smog exempt meaning no egr or catalytic converter). The ECM number is 1227165. I am using tunerpro xdf file 32.xdf and ads file 1227165-160.ads. I finally got the program to read the values from the ECM (no small feat in itself) and think the maf value is not good. Do you have a table of "normal" or expected values for a variety of operating conditions? (Key on, cranking, idling, partial throttle....). The temp, iac, and tps values seem to be good, 66F (cold), 144 steps, and .45-4.5V respectively. The maf reads 17430 and the o2 sensor reads 452.88mV with the key on but not running. There are no units on the displayed table for airflow but again with the maf reading so high makes me think the maf sensor is bad. The engine currently will not start.

I understand every situation is unique based on chip programming and engine configuration but I feel what I am looking is not that uncommon (chip programmed by Jim at tpis.com). A general idea if the values I see are in the ball park would be helpful. I have searched tunerpro, third-gen, moates, and many other sites looking for the information.

Again, what I am looking for is a table of "standard" values I should see from the maf and o2 sensor for a relatively stock normal motor in a variety operating conditions

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Mangus
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Post by Mangus » Tue Feb 09, 2016 9:55 am

both the O2 and MAF values while the car isn't running aren't particularly useful. You'll need to get the car running first before really exploring those values. The O2 should oscillate, centered around 500 mV, once the O2 is warmed up.

Can you run the stock tune?
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1989 Trans Am

IDcavy93
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Post by IDcavy93 » Wed Feb 17, 2016 5:39 am

NOOB here...
I'm amazed that an 80s EFI system uses a MAF! I didn't think GM started using that until the late 90s - even in Camaros! Especially on a TBI system.
I had a 93 Caprice police car with the 5.7 and it used speed density instead of the MAF.

My Cavy is MFI but is also speed density. The MAP reads around 92 kPa at key on here in Boise (2737ft) which my 1227730 uses as a baro check...

My NB O2 reads as described...oscillating around 500mV.

Not sure what my point is...just trying to add to the conversation and help!

:oops:

Byteme
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Post by Byteme » Thu Sep 15, 2016 8:44 am

94 for the Camaro is when they started the MAF sensor. Are you positive what that motor and PCM are from?

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Mangus
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Post by Mangus » Thu Sep 15, 2016 8:48 am

86-89 TPI Camaros, Firebirds, and Vettes used MAFs with the 1227165.
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Warnburt
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Post by Warnburt » Sat May 20, 2017 10:32 am

I never did receive a "standard values" table. I did read that maf and o2 values are unusable with engine off or cranking. During cranking the maf values read about 1600. I am not able to get engine to start. I have been able to log during cranking and the only anomaly I see is engine speed is zero at all times. I assume I f the ecm sees zero engine speed the injectors will not fire. I also see in the log table Rich/Lean reading lean. I also see Learn Control is disabled (BLM is 128). Any suggestions.

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