2 ?'s 1-scanmaster & 2-pcmforless? please help
10-07-2004, 10:21 PM
#1
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Join Date: Aug 2001
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2 ?'s 1-SCANMASTER & 2-PCMFORLESS? please help
Hey guys I could really use some input here.
1st problem is I installed a scanmaster in my 96 SS about a year and half ago and have been lucky to not have any sensor problems until now. My service engine soon light came on and when I went to see what the trouble code was on the scanmaster it just had the dashed line. So I went through the scan and noticed my clt temp was stuck at 40 deg. Come to find out the sensor on the waterpump is broken. Now can someone please tell me why the scanmaster didn't give me the code# for this?
2nd problem I took my car today to the dyno and I'm very disappointed to say the least. My sig has the mods and hp/tq for the original setup. Since then I called pcmforless for a custom tune for the future mods that I was going to put on. I told them I was going to be adding AS&M headers, Random Tech y-pipe (w/dual cats) 42lb injectors. Now when I got the new pcm and injectors I put them in and took it to the dyno to see what changed and the best I could get was 348rwhp and 354.8rwtq. So I thought maybe because the tune was setup for the headers and y-pipe it was getting screwed up. So I finally got the headers in after a 8 week backorder had everything put on and went back today to the dyno and my best was 364.6rwhp and 369.1rwtq. So I basically spend about 2k for an extra 6rwhp and 8rwtq. Does anybody have any suggestions?????? Would the broken sensor cause the computer to be more conservative with the timing or is this program just no where near what it should be. Everybody says that headers give you so much more power and I'm getting nothing and I lost 10hp from that stupid program.
Sorry for being so long winded but I could really use some advice here I am real upset with my results. Thanks
1st problem is I installed a scanmaster in my 96 SS about a year and half ago and have been lucky to not have any sensor problems until now. My service engine soon light came on and when I went to see what the trouble code was on the scanmaster it just had the dashed line. So I went through the scan and noticed my clt temp was stuck at 40 deg. Come to find out the sensor on the waterpump is broken. Now can someone please tell me why the scanmaster didn't give me the code# for this?
2nd problem I took my car today to the dyno and I'm very disappointed to say the least. My sig has the mods and hp/tq for the original setup. Since then I called pcmforless for a custom tune for the future mods that I was going to put on. I told them I was going to be adding AS&M headers, Random Tech y-pipe (w/dual cats) 42lb injectors. Now when I got the new pcm and injectors I put them in and took it to the dyno to see what changed and the best I could get was 348rwhp and 354.8rwtq. So I thought maybe because the tune was setup for the headers and y-pipe it was getting screwed up. So I finally got the headers in after a 8 week backorder had everything put on and went back today to the dyno and my best was 364.6rwhp and 369.1rwtq. So I basically spend about 2k for an extra 6rwhp and 8rwtq. Does anybody have any suggestions?????? Would the broken sensor cause the computer to be more conservative with the timing or is this program just no where near what it should be. Everybody says that headers give you so much more power and I'm getting nothing and I lost 10hp from that stupid program.
Sorry for being so long winded but I could really use some advice here I am real upset with my results. Thanks
Last edited by Bill's SS; 10-07-2004 at 10:35 PM.
10-08-2004, 12:00 AM
#2
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Re: 2 ?'s 1-SCANMASTER & 2-PCMFORLESS? please help
Are you still running an OBD-II PCM in your 96? If so, ScanMaster can not read codes on OBD-II.
I also think if you check, you will find that the coolant temp is indicating MINUS 40degF. That's what you get when there is an "open" in the circuit, repesenting resistance greater than 100,000 ohms. The PCM seeing that coolant temp is definitely going to hurt performance. It will prevent the system from going into closed loop. Might also be affecting PE mode target A/F ratio.
I also think if you check, you will find that the coolant temp is indicating MINUS 40degF. That's what you get when there is an "open" in the circuit, repesenting resistance greater than 100,000 ohms. The PCM seeing that coolant temp is definitely going to hurt performance. It will prevent the system from going into closed loop. Might also be affecting PE mode target A/F ratio.
10-08-2004, 05:31 AM
#3
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Re: 2 ?'s 1-scanmaster & 2-pcmforless? please help
Yes, I still have OBD II. What is PE Mode? 
What else is out there that I can get that will read computer codes. I was expecting to have around 380rwhp after all this was done, this wouldn't effect it that much would it?????? Thanks
What else is out there that I can get that will read computer codes. I was expecting to have around 380rwhp after all this was done, this wouldn't effect it that much would it?????? Thanks
10-08-2004, 06:02 AM
#4
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Join Date: May 2000
Location: Memphis, TN
Posts: 249
Re: 2 ?'s 1-scanmaster & 2-pcmforless? please help
To read OBDII trouble codes, you need something like Autotap. Or you could get a OBDI conversion from pcmforless.com or madz28.com and your Scanmaster will read your trouble codes then.
Also, being in open loop wont hurt performance any. The car is always in open loop at wide open throttle.
Also, being in open loop wont hurt performance any. The car is always in open loop at wide open throttle.
10-08-2004, 06:59 AM
#5
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Re: 2 ?'s 1-scanmaster & 2-pcmforless? please help
No, its not in "open loop".... its in "power enrichment mode" (PE) at WOT. Coolant temperature is one of the variables used to determine the target A/F ratio. Here's an excerpt from Chris Bennight's well written tuning document:
WOT Table
This is the percent TPS that will be required for the WOT bit to be set in the computer when the engine temperature is less than 151 C. This can be altered so that the computer is always in PE mode at idle rpm’s (thus O2’s are ignored) if so desired.
PE vs. Coolant Temp
This table contains the Power Enrichment (additional fuel) that will be added at WOT vs. the coolant temperature when in PE mode (WOT)
PE vs. RPM
This table contains the Power Enrichment (additional fuel) that will be added at WOT vs. the current RPM. This is typically where fuel tuning for WOT operation is done. Values can be positive (Adding fuel) or negative (Subtracting fuel).
This is the percent TPS that will be required for the WOT bit to be set in the computer when the engine temperature is less than 151 C. This can be altered so that the computer is always in PE mode at idle rpm’s (thus O2’s are ignored) if so desired.
PE vs. Coolant Temp
This table contains the Power Enrichment (additional fuel) that will be added at WOT vs. the coolant temperature when in PE mode (WOT)
PE vs. RPM
This table contains the Power Enrichment (additional fuel) that will be added at WOT vs. the current RPM. This is typically where fuel tuning for WOT operation is done. Values can be positive (Adding fuel) or negative (Subtracting fuel).
10-08-2004, 08:28 AM
#7
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Location: Reading, Pa
Posts: 521
Re: 2 ?'s 1-scanmaster & 2-pcmforless? please help
I also agree, get that sensor fixed. Also, what were the atmospheric conditions on the days you did the two different dyno pulls? Any big changes could also factor in. There are several small things adding up to give you the frustration you are experiencing. Get them worked out and you'll be on track. PCMforless does all my race tuning and their work is outstanding so I would be comfortable saying it's probably not in the new tune.
10-08-2004, 11:05 AM
#9
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Re: 2 ?'s 1-scanmaster & 2-pcmforless? please help
The atmospheric conditions were not really that different each time I dynoed. I plan on fixing the sensor today or tomorrow. N2Odave you said there are several small things adding up, can you please let me know what you mean besides the sensor. I figured I should have 380rwhp with this setup, maybe I was wrong. Everybody kept saying that headers will make a huge difference though and to me 6hp is not huge. Thanks guys.