canuck94z28

I just got my pcm(done by MADZ28) installed& my 52 mmtb. & @idle my scanmaster showed 0.74 volts& after i revved it a couple times i saw a reading of 0.76.Some other readings i got were 03 maf,146 on lbl & 138 on the right,the iac was 60.These again were @idle.I remember yrs. ago the tps voltage could be adjusted & to try for at least 5.0 volts @w.o.t.Anybody have any ideas on these #,s & can i get my tps voltage higher @ w.o.t or does the pcm adjust for the bigger tb.Thanks

Injuneer

You don't need to adjust your TPS voltage. I've never heard anyone aiming for 5.0V at WOT - the would actually set a code. Some people claim they get better results with an 0.50V closed throttle reading, but I've never found any logic to support this.

The LT1 PCM reads the closed throttle voltage when you turn the key on, and as long as its between 0.20 - 0.90V is accepts that reading as the 0% throttle reading, then adds about 4.0V to that reading to pro-rate the throttle percent as the throttle opens. At WOT it will typically read 4.0V higher than the closed throttle voltage, and that's fine, as long as it doesn't go over 4.90V. Over that will set a code for high TPS voltage.

The difference between 0.74V and 0.76V is insignificant. Appears there might be a minor bit of friction in the throttle cable or the linkage.

3GPS on the MAF reading at idle seems very low. Typically you will see 6.0 GPS or higher. The BLM's indicate that its either running lean, and the PCM is adding 14% extra fuel on the left side, and almost 8% extra fuel on the right side to bring the A/F ratio back where it belongs. OR.... you have a false lean condition and the PCM is adding fuel the engine doesn't need.

Read this:

http://www.injuneer.com/Scanner.html

canuck94z28

Thanks again for that valuable reply.I have some of this writen to my scanmaster manual & i will try another maf sensor & see if readings are similiar when i can get car out of storage.

canuck94z28

Update.I bought another maf from a salvage yard last spring(2010)& that reading of 3.0 gps@ idle is the reading that i get now all the time.I did see 6.0 w/ my orig. one(i still have btw).I was told the salvage one was from a 1996 1500 gm truck.Would this cause my reading to be what it is?Any ideas on this.Also, like i said those other readings will be looked at more closely in a couple months as the readings i got might be affected by car not being started /run for 4 months,old gas,etc.

shoebox

You can't just throw a MAF from any old car (or truck) on the car. It's calibration may be different. A MAF reading by itself is not comparable to another without knowing other operating parameter values occurring at the same time.

canuck94z28

Thanks for the reply .Like i,ve said the car seems to run ok w/that truck maf but since i still have the stk. one i,m going to do some back-to back comparisons.