[V8Vairs] GM TPI question

[George Jones]

Tim,

Thanks for the info. It's nice to hear that the system is that forgiving. Is your system a speed density, of a MAF system. I believe after 1990, all the TPI systems went to speed density (and picked up VATS). I understand that Speed Density is cheaper, much easier to use and is more forgiving of engine changes, but the MAF system is much more accurate (efficient). I don't understand why GM would have gone to a less efficient system when the pressure is always on to reduce emissions and increase fuel mileage.

Maybe I'm just confused. Tell me more about the Vortech SPFI system...
How did you get past the anti-theft system? Was the truck download the only one you could use? Wouldn't it have been better to use a program from a Vette? Where did you download the firmware from? What were the stumbling blocks you encountered?

Thanks,

George Jones
'65 Monza Convertible Crown V8




 --- On Mon 02/12, Tim Barrie < tbarrie at meritprecision.com > wrote:
From: Tim Barrie [mailto: tbarrie at meritprecision.com]
To: bubblehd at excite.com, v8vairs at corvair.org
Date: Mon, 12 Feb 2007 09:27:14 -0500
Subject: RE: [V8Vairs] GM TPI question

George, I am using a '96 Vortec with the sequential fuel injection. I usedthe original harness and computer and it was surprisingly very easy. I wouldthink that the TPI would be just as easy.You need the wiring diagram for the engine and access to a GM scan tool whenyou start it up.I just pulled the pins out of the computer plugs for each sensor that Iwasn't using. There are only a few that you must have to make it run. TheVSS isn't required. I spent about 40 hours doing this as I ended up changingthe length of every wire to accommodate the new placement of the computer.I didn't have the original computer for the engine so I picked one up at thesalvage yard. It was actually out of a V6 but my engine started up and raneven with the distributor out by a tooth. I went on ebay and found a '96 truck for sale with a standard trans. I usedthat truck's VIN to download the correct program into the computer using thescan tool.  Started it up, it idled at 700rpm and all of the sensors 
checkedout with correct readings.I believe that you would only need the VSS if you are going to retain CruiseControl and/or an automatic transmission with electronic shifting. Tim-----Original Message-----From: v8vairs-bounces at corvair.org [mailto:v8vairs-bounces at corvair.org] OnBehalf Of George JonesSent: Sunday, February 11, 2007 10:26 PMTo: V8Vairs at corvair.orgSubject: [V8Vairs] GM TPI questionI'm looking at the possibility of replacing my Edelbrock Performer and 4160carb with a GM TPI set-up. I've been doing some research on the conversion,and the only problem I see is with the Vehicle Speed Sensor (VSS). From whatI see, this is a critical requirement to have the ECM function properly. Thequestion I have, is; where, on a Crown drivetrain, can I install a VSS? Fromwhat I've read, the normal location is at the output of the transmission,obviously difficult to do on the Crown._______________________________________________Join Excite! - http://www.excite.comThe most 
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