S10Wildside

Any thoughts/opinions about an OBDII TPI engine?

__________________
http://www.eficonnection.com


1991 Trans Am Convertible (Project)
5.0L TPI Engine, T5


2000 Firehawk
Trans Am, SLP Firehawk, LS1, 4l60E

Vader

Are you considering this for the sequnetial injection? Would you try to incorporate individual spark timing, too? Would you use both the MAF and MAP? I can see no other benefits to changing to an OBD II PCM, and either would require a cam and crank position sensor, and possibly a higher resolution crank sensor depending upon the system used.

S10Wildside

Individual spark timing: no
MAF and MAP: possibly, maybe just MAP

Benefits as I see them:

• Sequential Fire
• 4L60E/4L80E Control
• VSS Sensor Control
• Custom Operating Systems for Forced Induction (EFILive)
• Auto VE Correction (EFILive)

I was surprised to recenty learn that the 01-02 LS1 PCM 12200411 was used in the 01-02 Express Van that still uses the Gen 1 small block (L31) with cam sensor (distributor) and crank sensor with external igniton module and coil (like the LT1).

Currently EFILive supports this PCM and offers some pretty cool features (auto VE correction, custom OS, etc).

Possibly next weekend I'm going to convert a L98 to work with the 01-02 LS1 12200411 PCM on my test stand. I almost have all the parts. Since I've been rewiring my S-10, I'm going to begin building a new engine harness for these newer electronics. I really like the idea of using the 4L80E with my truck.

V8Rumble

I for one find the idea a bit intriguing... I'd appreciate it if you'd keep us apprised of what you learn.

S10Wildside

Sure...

Here's a list of parts (this will be revised until the engine is running and I know the list is complete):

• 12200411 PCM (LS1, Truck, S-10, Blazer, Express, others)
• Wiring Harness for 12200411 (must follow Vortec L31 schematics)
• Vortec 305/350 Distributor (has camshaft sensor in it)
• Vortec 305/350 Harmonic Balancer
• Vortec 305/350 Timing Cover
• Vortec Timing Reluctor Ring (goes behind timing cover)
• Vortec Crank Position Sensor
• Vortec Ignition Module
• Vortec Coil
• Knock Sensor (2001 Express Van w/ 5.7 engine)
• 01-02 Express Van HO2 Sensors

Let me suggest that the O2 sensors from the Camaro/Firebird will probably work, but they use different connectors (but wired the same to the PCM). The Corvette sensors use the same connector as the Express Van. Please look beyond what vehicle the sensors were used with. The O2 sensor simply returns a voltage to the PCM that represents the air/fuel mixture. Zero volts being lean, 1.0 volts being rich. The Corvette sensor is no better than the Express Van sensor.

I just installed the Vortec distributor into my TPI engine. It completely clears the runners, but will require relocating the coil. The distributor is offset just like the runners are (bank two is set further forward than bank one).

scuzz

S10Wildside can do it!
He has also built the same harness for my streetrod project.
It looks great, and I'm installing it next week. He made the injector harness to work with Ramjet instead of TPI. Either should work great.

Fast92RS

I was always wondering about this. I'd like to see how it turns out. I think with MAF would be better in the long run for future mods. Would it be possible to convert a factory TPI harness to OBDII?

Fast355

I've already done the swap with a TPI 305 van (1994 G10 w/ 4L60E). I used the OBDII SFI PCM from a 1998 Express Van.

1989GTATransAm

Sounds interesting but I have to pass smog in Kalifornia. Will the smog technicians know there is a different computer in the car than what is supposed to be there?

S10Wildside

There are a few snags in doing this.

PCM Location
The LS1 PCM will not fit under the 3rd gen dash.

Passenger Side Harness Bulkhead
The molded bulkhead ECM harness connector in the passenger side pillar does not pass enough wires through it for the LS1 PCM. You can not easily add more wires. The extra wires are for injectors, transmission, and the individual sensor ground wires from the PCM to the TPS, CTS, IAT, and MAP. (The TPI ECM has these shared...paired for speed density, shared for mass air.)

I could build a plug and play third gen harness (not quite 100% plug and play), but have no intentions of doing this anytime soon. There would be a lot of hours into it until a template is made.

bingo

Why would the PCM not fit? I have an LT1 PCM under my dash and they are about the same size.

S10Wildside

You're using the computer on the left (96-99 Vortec Truck/Van), and I'll be using the computer on the right (01-02 LS1/Truck/Van/S10).



It's my understanding that there are a few annoying limitations with the early Vortec computer (no way to get around the 5800rpm fuel cut-off). Someone correct me if I'm wrong...I can't even back that up with supporting documentation...but I know there's a discussion at Monodax Homepage - TunerCat OBDII Scanner and Data Logger - MXScan Info- about it.

Currently, EFILive is making the 01-02 PCM a very powerful piece of equipment. With custom operating systems available, you won't need to consider aftermarket PCMs for high horsepower applications. And these used PCMs are available in yards for under $40.00!

S10Wildside

Good to know. I guess you'd need a custom mounting bracket then. The LT1 PCM is pretty much the same size as the LS1 PCM.

S10Wildside

I'm not sure what they're testing for exactly, but I suppose you could still run smog equipment. I don't know if the smog techs care about the engine computer being used.

S10Wildside

I'm still on track for making this happen this upcoming weekend. I'll have the camera with me to show what's involved.

All I'm waiting on is a crankshaft timing ring and EFILive. They should both be here this week.

I also need to find documentation about installing the new distributor (crankshaft and camshaft positions). I did a little reading at AllDataDiy.com, for the 2001 Express Van, but it wasn't as specific as I had hoped.

Fast355

I am using the old black PCM with the 5,800 rpm limit. I am also limited by the stock LTR TPI intake, so I am not that worried about it. This is for mid-range torque and mileage, not HP.

As far as dropping in the distributer, it is easy. Just turn the crankshaft over until you get to TDC on number 1, then look at the distributer cap to find where the number 1 position will be, turn the rotor about 30-40* counterclockwise from number 1 and drop it on in, it should now line up with the number 1 wire on the cap. You can tell pretty easily which contact goes to number 1 by looking at the top of the cap. My vortec distributer had a white line that faced the rear of the engine when properly installed. When I started the engine and looked at the cam/crank correlation I have been within +/-1* on all 3 Vortec engines that I have built.

PS- It is in my plans to re-pin the existing harness into a 2001-2002 Vortec Van silver PCM, but I haven't gotten around to it yet. The old style PCM isn't all that bad, just the rev limiter thing.

S10Wildside

Easy enough. Thanks!

Did you have to perform the crankshaft relearn procedure?

Fast355

I never had to do the crankshaft relearn procedure, but I have never used the 2001-2002 PCM either. I have done this 3 times with the older 97-98 PCM and never had an issue.

I know that the guys that get PCM "TUNES" over on Fullsizechevy have to get them done.

Fast92RS

In that case the bulkhead would have to be cut out and removed and just use a big grommet or something like that to pass all the new wiring through.

S10Wildside

I had said not easily because the connector can be carefully disassembled using a heat gun.

S10Wildside

Well it runs...

..and what a long day. The crank reluctor ring is no big deal to install...and it can only go on one way without slipping. It's obvious that the Vortec balancer has a slightly different height (from end of balancer toward crank) because of the extra distance the reluctor ring takes. So, the Vortec balancer is required when doing this conversion.

I like the way the wires lay with this distributor.



The engine started right up and threw the following (expected) codes:



I was unable to successfully perform the crank relearn procedure. I initially had a transmission code P1810 that was preventing the relearn procedure, but after disabling that code, I still can't perform the relearn. I'm stumped. So I'll try disabling all the tranny codes and see if the relearn procedure will cooperate.

It's still a great start. The engine fires up immediately and runs great on the LS1 PCM (considering the relearn issue).

bingo

This setup would be sequential wouldn't it. Is that a new model MAS I see in the pic?

__________________
90 Firebird Formula (Stephen)Soon to be sold
LT1/T56(formerly 305TPI/T5), 355 with LE1 heads and cam, Hooker 2210s, 1le Brakes, alston subframe connectors, Spohn tubular control arms and panhard rod, Jegster torque arm, Richmond 4:10 gears and all new interior and paint.
Working A/C!
My car on Cardomain (updated 12/27/06).http://www.cardomain.com/ride/2415999/1

92 Oldsmobile Silhouette (Agnes)

62 Galaxie 500 An old friend that found his way back.

Fast355

Yes, it is.

S10Wildside- too bad you don't grab a 4L60E case and stuff it with your 700r4 guts.

S10Wildside

Sequential - yes
GM 85mm MAF - yes



The 85mm MAF is a great alternative to the original one used with the Vortec and LS1 applications. It's a 5 wire sensor where three wires are used for the MAF and two are used for the IAT sensor. This is desirable if NOT swapping to speed density (and not deleting the MAF) because the IAT is built in and doesn't need to be mounted somewhere. It does require a change to the MAF table values. I swapped in the values from my 2003 Silverado SS. It's actually a very common MAF sensor. It's sometimes referred to as the Z06 MAF, but it's found in 99 and newer full size trucks, too.

Some wires are extra long because I built this harness to go in my S-10, but am using it on the test engine at the moment.

bingo

I am about to do a TPI swap on my Grand Prix and this idea is very interesting. I know the newer PCMs are superior to the older ECMs, but what would this cost? I have all my parts, but this would be a nice upgrade later.

S10Wildside

The cost could completely vary. I purchased many of the Vortec parts on ebay for a very low price. The knock sensor for the 01 Express Van (5.7L)was a different part number than the 90-92 TPI (5.7L) knock sensor, so I added that to the list above. The crank sensor and ignition module are very pricey new, so I'd either pull one from a yard or watch ebay. The PCM is very common and can be easily had for less than $40.00.

Consider a TPI ECM:
- about $40.00 for used 1227730 ECM
- about $70.00 for a new memcal
- about $35.00 for the Moates adapter to get around the OTP proms

When you break down all the parts and compare to the cost of original TPI parts, sometimes you'll see that the OBDII setup is cheaper, and sometimes the original TPI parts are cheaper. Overall, the original TPI stuff is still cheaper...but that all depends on the transmission used, VSS used (12200411 PCM can work with more VSS signals), etc.) If you were set on a OBDI TPI with 4L60E/4L80E, aftermarket transmission controllers are currently very expensive (over $600.00).

I could go on and on...

soultron

I'm smiling from ear to ear right now. that's sweet.

Fast355