For years now, enthusiasts have been retrofitting early project cars with LS-series engines and Gen III PCM conversions. The available features (cable or electronic throttle, cruise control, forced induction support, and so on) make the Gen III PCMs highly desirable for nearly any conversion.
The following projects are fine examples of Gen III control systems for small-block engines, turbocharged V-8 and V-6 engines, LT1 engines, and big-block engines.
Project 1: 24x Small-Block Chevy in a 1933 Willys
This 1933 Willys was built and owned by Bill Adam. The car originally had a 5.7L TPI engine from a 1987 Camaro Z28 and an ECM from a 1990 Corvette. Bill chose to upgrade the ECM to the GM# 12200411 PCM for greater tune-ability and a future 4L60E transmission install.
This tech tip is from the full book, HOW TO USE AND UPGRADE TO GM GEN III LS-SERIES POWERTRAIN CONTROL SYSTEMS.
For a comprehensive guide on this entire subject you can visit this link: LEARN MORE ABOUT THIS BOOK HERE
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This is Bill Adam’s 1933 Willys. I met Bill in 2002 when he and his son, Troy, heard there was a guy down the road (me) playing with TPI engines. Bill is a retired toolmaker and fabricated just about everything in this car. He was one of the first in town to install a fuel-injected V-8 engine in a street rod. When I first met Bill, his Willys had an original 1987 5.7L TPI engine with aftermarket wire harness and an ECM (GM# 1227727) from a 1990 Corvette. The Willys ran great, but after seeing some of the newer technology I was playing with, Bill couldn’t leave well enough alone.
GM 4x Vortec Small-Block System
In 2006, Bill and I worked together to upgrade the ECM to a 2002 PCM (GM# 12200411) for single coil and distributor operation using a 1996–2002 ignition system and 2002 Express Van calibration file. In hot rodder fashion, the electronics upgrade turned into a heads-up upgrade, including ported aftermarket heads, LT4 hot cam, and TPIS Mini Ram intake manifold. Ultimately the conversion to the GM truck ignition system with this PCM was a failure due to a persistent corrosion problem within (several different styles of) the Vortec distributor.
EFI Connection 24x Small-Block System
Bill was ready to throw in the towel and go back to the TPI ECM. But by then, the prototyping of an EFI Connection24x crankshaft reluctor for small-block engines was nearly complete. So, Bill’s Willys became the first vehicle to receive a 24x conversion (the second was my S10 Wildside pickup).
Bill fabricated his own ignition coil mounts by drilling holes through a set of aftermarket die-cast aluminum valve covers and attaching threaded posts to screws from the back side of each valve cover. These LS1/LS6 ignition coils don’t allow much room for oil fill, PCV valve, or breather holes. An alternative choice for better clearance is a set of GM# 12573190 ignition coils.
This was the first engine to receive EFI Connection’s 24x conversion. At the time of prototyping, the 1996-newer Vortec V-8 plastic timing cover was the only choice for this application. Due to a slight mismatch of timing cover sealing surfaces between early and late engine blocks, Bill chose to apply JB Weld to the face of the block to extend the seal surface. The TPIS billet-aluminum SBC timing cover now resolves this sealing issue.
Mounting the ignition coils on the valve covers is not for everyone, but this engine bay offers no other room for cleanly mounting the eight coils.
Removing the high voltage from the Vortec distributor, we only needed the camshaft position signal it provides. Moisture or no moisture within the distributor cap, Bill no longer had to worry about ignition problems related to the Vortec distributor. The 4x Vortec small-block crankshaft reluctor was removed and replaced with the first 24x small-block crankshaft reluctor.
Timing Cover
A problem with any crankshaft reluctor installation on an engine that did not originally have a crankshaft reluctor (1995-older) is that General Motors changed the timing cover sealing surface just enough that the 1996- newer plastic Vortec timing covers leak. Although TPIS has since resolved this problem with a machined billet aluminum timing cover, Bill cleaned the face of this 1987 block to apply JB Weld to the trouble areas, ground the new surfaces flat, and then generously applied red RTV sealant to protect against oil leaks.
For the hassle and oil leak risk involved, you are better off buying the TPIS billet-aluminum timing cover and being done with it. TPIS designed their billet-aluminum small-block timing cover for original crankshaft sensor placement, making this beautiful timing cover a direct bolt on for 1996-newer small-block engines as well.
TPIS designed and manufactures this beautiful billet-aluminum timing cover for small-block Chevy engines. This timing cover eliminates oil leak issues of the 1996-newer Vortec V-8 timing cover when used with a 1995 or older small-block Chevy engine.
Speed Density
Bill initially chose the 1990 TPI ECM because it offered speed-density operation. The 1990–1992 TPI ECMs use a MAP sensor to determine how much fuel to deliver. With tight clearance ahead of the throttle body, and a mechanical fan, a MAF sensor was not possible in this engine bay. The 1996-newer GM fuel management systems use both a MAF and a MAP but the MAF sensor is often eliminated and the PCM is programmed to rely on the MAP sensor for fuel delivery.
Ignition Coil Selection
Bill chose to use LS1 ignition coils (simply because they were available). Some owners unnecessarily get caught up with ignition coil selection. General Motors has used five types of ignition coils (see Chapter 6). Any set of eight ignition coils can be used interchangeably. In fact, among LS-series engines, all ignition coil wire harnesses match every LS-series engine wire harness.
Be aware that the PCM calibration has dwell settings that may need to be adjusted if you use a different set of eight ignition coils. EFI Connection uses the very common GM# 12573190 ignition coils because they fit best on the small-block/LT1 valve covers to allow clearance for oil fill cap, PCV valve, and breather.
DTCs on Startup
Production GM vehicles contain solenoids, relays, sensors, and on-board modules not used in most conversion projects. Upon initial startup of your Gen III PCM conversion, you may notice DTCs that have set related to something that is not used in your vehicle.
Using a base calibration from a 2002 LS1 Camaro with a 4L60-E transmission, the Willys set more than 30 DTCs immediately following the first engine startup. DTCs related to the 4L60-E transmission, emissions equipment, air conditioning, cooling fans, and alternator (that covers just about all of them) can be disabled because the LS1 PCM is not controlling or monitoring this equipment for this vehicle. The mass airflow DTC (P0102) is actually required for DTC processing for speed density operation, but the calibration is set to never illuminate the MIL. It is “normal” for a conversion and clearly explained in EFILive documentation.
VATS Bypass Modules
Almost daily, enthusiasts throw money away by purchasing VATS bypass modules. I quickly found one of these modules on eBay advertising, “Normally it costs between $150 and $300 to have this feature deleted from the PCM. By using our module you accomplish the same function for less and you won’t have to ship your PCM/ ECM to have it reprogrammed.” A VATS bypass module is often purchased during the parts gathering phase of a project and then not used.
The problem with using a bypass module is that the PCM still requires programming to disable other functions specific to the original car. No matter how well-built these modules are, they do nothing more than allow the engine to run so that you can be greeted with an MIL that indicates you need your PCM reprogrammed.
The PCM calibration requires a few changes beyond disabling VATS. Avoid the VATS bypass module and let your tuner disable VATS in the PCM calibration while making other necessary changes.
700R4 Transmission
Bill and I began with a PCM calibration from a vehicle with a 4L60-E transmission so the idle table values would be appropriate for the 700R4 automatic transmission in the car. The PCM immediately sets DTCs related to the 4L60-E transmission. We disabled these within the PCM calibration using EFILive tuning software. This is an appropriate step as they are disabled in a PCM calibration from a manual transmission vehicle. Had General Motors released an LS-series vehicle with the 700R4 transmission, they too would have disabled these DTCs. Bill and I had the foresight to build the engine wire harness to support a 4L60-E transmission.
General Motors appropriately enables (and disables) DTCs for production vehicles according to the features specific to each vehicle. A Gen III LS PCM conversion requires certain DTCs to be disabled according to the features being used in the retrofit vehicle. The first engine startup revealed this list of DTCs that were later disabled (turned off). These DTCs are appropriate for the 2002 Camaro LS1/4L60E, but not for a 1933 Willys.
Cruise Control
Adding cruise control to the Willys was an afterthought. The installation was completed; start to finish, over the better part of a Saturday. We scored a used 1998 LS1 Camaro cruise control module on eBay for about $50 and pulled a brake switch from a 1996 LT1 brake pedal assembly that was lying around. The addition of cruise control set us back about $75 and several hours of labor. The Willys required a slight variation on the typical cruise control wiring (see Chapter 14).
First, Bill prototyped a throttle body linkage adapter for the TPI throttle body. This was the most difficult part of the installation because the cruise control cable was designed for an LS1 engine throttle bracket and throttle body. This adapter can be reworked for a better, and cleaner, installation.
Bill identified a stealthy location for the cruise control module beneath the driver’s seat and on the bottom side of the floor. The F-Body cable is plenty long enough to mount the cruise control module out of sight.
Bill had to make a custom throttle cable adapter to receive the 1998 Camaro Z28 cruise control cable. Here a prototype is shown during installation.
A new wire harness for the cruise control module is shown on the floor next to Bill as he is routing the wires up the pillar in front of the door.
This wire schematic represents the implementation of a 1998 Camaro Z28 cruise control module into the Willys. Notice the PCM’s secondary VSS output was used to provide a 4,000 pulse-per-mile signal to the cruise control module as the primary VSS output was already used for the speedometer. The 1998 Camaro Z28 cruise control module does not require the cruise engaged status or cruise inhibit signals.
Although a 1996 Camaro/Firebird brake switch was installed for proper cruise control signals, many other GM brake switches provide the same signals.
To satisfy the cruise control module’s 4,000 pulse-per-mile VSS input requirement, a terminated wire was inserted into cavity 49 of the red PCM connector (PCM secondary VSS output).
This early GM steering column contained a cruise control set/coast switch only. There was no provision for the accelerate/resume functions.
The 1998 Camaro Z28 cruise control module fit comfortably between the frame rails of this Willys. The Camaro/Firebird cruise control cable is much longer than the GM truck cables. This cable length was ideal for hiding the cruise control module under the vehicle.
With the PCM’s secondary VSS output circuit now attached to the cruise control module’s 4,000-pulse-per-mile VSS input, a calibration change was made to set the PCM’s pulse count to 4,000.
While we could have used just about any GM brake switch from a vehicle with cruise control, we had a 1996 F-Body brake switch that fit nicely within the tight space of the dash. We tapped into the stop lamp circuit and TCC brake signal circuit to satisfy the cruise control module’s brake switch signal requirements. Bill used a steering column from an early GM vehicle with cruise control. The multi-function lever (turn signal and cruise control switch lever) only had the set/coast feature, so we wired the cruise ON/OFF to switched 12V ignition, ignoring the resume/accel feature.
The cruise control module requires a 4,000 pulse-per-mile VSS signal, so we looked to the LS1 PCM. The PCM’s primary VSS output was already being used for the speedometer (red connector, cavity 50, green/white wire), so we used the PCM’s secondary VSS output wire at the red connector, cavity 49. The final step was to change the PCM’s secondary VSS output signal to 4,000 pulses per mile using EFILive tuning software.
Conclusion
Bill’s 1933 Willys is a fine example of a Gen III PCM bringing modern fuel injection, tuning, and additional nice-to-have features (such as cruise control) to an early street rod. The only improvement left for the Willys is a 4L60-E transmission upgrade. The 700R4 has seen better days and Bill is already looking forward to the drivability improvements after a 4L60-E installation.
This tech tip is from the full book, HOW TO USE AND UPGRADE TO GM GEN III LS-SERIES POWERTRAIN CONTROL SYSTEMS.
For a comprehensive guide on this entire subject you can visit this link: LEARN MORE ABOUT THIS BOOK HERE
SHARE THIS ARTICLE: Please feel free to share this article on Facebook, in Forums, or with any Clubs you participate in. You can copy and paste this link to share: https://www.lsenginediy.com/gen-iii-ls-pcm-conversion-upgrades-projects-lessons-strategies/
Project 2: Twin-Turbo Small-Block Chevy in a 1998 GMC Truck
Jeff Jones’ Twin-Turbo 1998 GMC truck. (Photo Courtesy Jeff Jones)
Jeff Jones is the owner of a unique 1998 GMC Sierra. Although his professional automotive day job is as a Lexus technician, his automotive hobby includes GM engine performance. Looking for more performance from his 5.0L Vortec engine, he went to the salvage yard to source two turbos for a little added “boost.” The plastic Vortec intake manifold was problematic for several reasons, including the inability to properly size fuel injectors for the additional demands of using two turbos. A Ram Jet 350 intake manifold was a direct fit to the 5.0L Vortec engine and allowed for external fuel injectors, a forward-facing throttle body, and better airflow than the original intake manifold. The next issue was to address the limitations of the 1996–2000 Vortec “black box” PCM that General Motors designed to power the truck.
PCM Considerations
Jeff’s twin-turbo build required a better PCM than was in the car. The truck’s original black box PCM is not capable of reading boost or MAP sensor values above 105 kpa. He dismissed aftermarket ECUs with a hunch that a newer GM PCM may allow for the rest of his truck (gauges, transmission, air conditioning, etc.) to remain fully functional. Jeff knew that the Vortec 5.0L engine in his GMC was used through 2002 in the Chevy Express Van and that the 2002 Express Van used the same PCM (GM# 12200411) that is used with 2002 LS-series engines.
EFILive COS forced-induction table showing MAP above 105 kpa.
LS1 PCM connectors, retainers, dress covers, terminals, and removal tool.
With the buzz on Internet message forums discussing LS1 vehicles being tuned for forced induction while using the original GM PCM, he had a promising direction forward. Thanks to EFILive, the GM PCM can be loaded with a custom OS to fully support forced induction.
Repinning the Engine Wire Harness
While wiring in a new PCM may seem like an enormous task, General Motors has made this rather easy by using the same connector terminals for 1996–2000 truck PCMs and the 2001–2002 GM# 12200411 PCM. The connector family and series are Delphi Micro-Pack 100W. Although the connectors are different, the terminals are interchangeable. All that is required is a terminal removal tool (or your fingernail), wiring diagrams, and a little time.
Jeff has been helping truck owners repin their black box PCMs for the newer PCM (GM# 12200411) for years through a well-documented repin guide. The Gen III PCMs require two 80-cavity Micro-Pack 100W connectors; each connector uses two colored and indexed retainers. This PCM requires two blue retainers and two red retainers.
GM# 12200411 LS1 PCM installed in the truck. (Photo Courtesy Jeff Jones)
Instrument cluster removed. (Photo Courtesy Noel Schnell)
The 1996–2000 PCM is located on the driver-side fender in the engine bay. The engine wire harness is easily accessed and serviceable when disconnected from the PCM. The Vortec black box PCM uses four (sometimes five) connectors.
The new PCM fits nicely in the location of the original black box PCM. The engine wire harness is repinned, one wire at a time, with the two 80-cavity LS-series PCM connectors. If you take your time, you can make the harness rework of the new PCM look as if it has always been there.
Gear Select Switch
In an automatic transmission vehicle, the PCM needs to know when the transmission is in park or neutral (P/N), or in gear. Manual transmission vehicles do not have a gear select switch.
In 1996–2000 GM trucks, the automatic transmissions have a gear select switch mounted on the side of the transmission case. The four-gear select switch wires are routed to the instrument cluster. Jeff chose to splice into these four wires from inside the truck to avoid corrosion and weather-related issues that can occur if the splices are made under the truck.
Because the first use of this PCM (GM# 12200411) in this 1998 GMC truck was with a calibration from a 2002 Express Van (4x crankshaft reluctor), the calibration’s gear select switch type was already set to PRNDL (because the 2002 Express Van has a gear select switch on the side of the transmission).
Gear select switch type.
After the 24x conversion, Jeff began with a 2002 LS1 Camaro/Firebird calibration and had to change the gear select switch type from P/N Switch to PRNDL. The LS1 Camaro and Firebird do not use a gear select switch on the side of the transmission since a P/N switch is in the center console that applies a single ground signal to the PCM (blue connector, pin 34) to indicate P/N.
An alternative after a 24x conversion is to begin with a calibration from an LS-series truck because the calibration is already set to the gear select switch type of PRNDL, as LS-series trucks have a gear select switch mounted on the side of the transmission case.
Electric Fans
Dual electric fans from a 2002 LS1 Firebird were installed after the PCM conversion. The Gen III PCMs can control up to two electric fans. The PCM does not supply power and ground for the fans, it supplies the ground trigger to the fan relays. The fan relays supply the power and ground for the fans. A quick trip to the local salvage yard sourced three relays and connectors for the wiring involved. By using the three relays, as is done in the LS1 Camaro/Firebird, the PCM can command low-/ high-speed operation of the two electric fans. (See Chapter 9 for more about electric fan operation.)
After the dual electric fan installation, Jeff added the Camaro/Firebird three-wire A/C pressure sensor for proper operation of the electric fans when the A/C was on. Now the cooling fans cycle properly to meet the demands of the A/C system. (See Chapter 11 for more information about A/C operation.)
The LS1 Firebird electric fans are mounted neatly behind the radiator.
4x Crankshaft Signal: Single Coil and Distributor
On a Vortec small-block engine, the CKP sensor signal output is 4x and CMP sensor signal output is 1x. The ignition system for all Vortec small-block engines is single coil and distributor. Although the ignition system remained the same, the new PCM brought the benefits of forced induction support, electric fan operation, engine speed beyond 5,800 rpm, and popular tuning software support. After all, locating a chassis dyno facility that is fluent with the LS-series PCMs is rather easy.
24x Crankshaft Signal: Coil-Per-Cylinder Ignition
Several years after the PCM conversion, this 5.0L Vortec engine received an EFI Connection 24x crankshaft reluctor and new crankshaft sensor. Having already repinned the engine wire harness at the PCM, all that had to be done was add 10 ignition coil control wires and use the 12V switched ignition and ground wires from the original ignition module and coil wiring to power the eight LS ignition coils. Rather than mount the ignition coils on the valve covers, a bracket was made to mount them on the firewall.
Throttle Swap
Jeff has been gathering parts for a swap from cable throttle to electronic throttle. With a 24x crankshaft reluctor in the engine, he may install a 2003-newer Gen III PCM. Electronic throttle equipment is plentiful in 2003-newer LS-series trucks, but he will run into a snag with electric fan operation while the A/C is on because the 2003- newer GM trucks eliminated the 12V A/C request to the PCM.
A workaround is to activate the electric fan relays from the A/C control switch (and disable the resulting electric fan DTCs in the PCM calibration).
To keep PCM-controlled electric fan operation while the A/C is on, either LS1/LS6 Corvette electronic throttle equipment or 1999–2002 GM truck electronic throttle equipment may be used while retaining the PCM (GM# 12200411). (See Chapter 8 for more information about electronic throttle equipment.)
Regardless of his choice, the Ram Jet 350 intake manifold accepts any Gen III throttle body and the cruise control switches in the steering column multifunction lever integrate seamlessly with any Gen III TAC module. With several electronic pedal assembly options, a custom mount and possible alterations to the pedal length may be required to properly locate the accelerator pedal pad.
Final Thoughts
The PCM swap was the foundation for every modification that has been done to Jeff’s truck. He considers this project and PCM-related upgrades to be one of the most educational and fun things he has ever done. From Internet message forums, Jeff has learned from people around the world with this same passion, and they shared information and creative ideas. Through this DIY project, he has created unexpected friendships that help to keep this passion alive.
Engine bay. (Photo Courtesy Jeff Jones)
Engine bay showing electric fans. (Photo Courtesy Jeff Jones)
Ignition coils on firewall. (Photo Courtesy Jeff Jones)
Front of truck with “LEX TEK” plate. (Photo Courtesy Jeff Jones)
I met Jeff at his home while en route to the 2009 Car Craft Summer Nationals event. Sharing his genuine passion for GM engine management fuels my flame for this exciting hobby. Don’t let the Lexus technician title fool you; Jeff represents GM performance through and through!
Project 3: Turbo 4.3L V-6 3x Conversion
Syclone/Typhoon lower intake manifold with six injectors.
Fuel injection for GM’s popular 4.3L V-6 engines was introduced in the 1980s with a TBI unit on the top of the engine’s intake manifold. These TBI units use two fuel injectors to distribute fuel in a central location within the intake manifold. Engine vacuum pulls the air/ fuel mixture into each cylinder for combustion. These early 4.3L engines are controlled by ECMs designed to be used with the two TBI injectors.
The 1991 GMC Syclone received the first 4.3L V-6 engine to feature multi-port injection; it had six individual fuel injectors for fuel delivery into each cylinder head intake runner. This improved method of fuel delivery required a new ECM with internal drivers capable of operating the six high-impedance fuel injectors. Although six fuel injectors are used, the ECM has only two injector drivers to run a batch fi re mode (one bank of three injectors at a time). Sequential fire injection was not available for the GMC Syclone or GMC Typhoon.
The 1991 GMC Syclone and 1992–1993 GMC Typhoon do not share the ECM or ignition system with any other 4.3L V-6 engine application. The unique requirement for forced induction, a turbocharger fitted on these 4.3L V-6 engines, was an ECM and calibration capable of controlling the engine’s six fuel injectors and spark advance while under boost (2-bar) conditions. The typical 4.3L V-6 ECM of those days was not designed to be used with this turbocharged engine.
With upgraded engine components (and more boost), 4.3L V-6 owners have gone to the aftermarket to install new (and expensive) fuel management systems for greater tune-ability and control of their powerplant. Unfortunately, aftermarket systems may lack support for the vehicle’s gauges, cruise control, and transmission torque converter lockup control, thus requiring additional aftermarket solutions that only add to the expense of an upgraded fuel management and ignition system.
Gen III PCM
Here is great news for the 4.3L V-6: General Motors has inexpensive production parts available to use the Gen III PCM with any 4.3L V-6 engine. The 2001–2002 PCM (GM# 12200411) was used with both LS-series V-8 engines and the 4.3L V-6 engines found in S-series trucks and vans. These engines are fitted with the 1996-newer 3x crankshaft reluctor and single coil and distributor Vortec ignition system. The same tuning software, such as EFILive, is used with this PCM, regardless of V-6 or V-8 calibration. Other tuning benefits, such as custom operating systems for 2- and 3-bar MAP support, are conveniently included.
GM’s 3x crankshaft reluctor for Vortec V-6 engines is shaped to allow clearance for only a single roller timing chain. Production GM engines use a single roller timing chain, so if upgrading to a double roller timing chain, EFI Connection’s 3x billet-steel crankshaft reluctor is required for reluctor-to-timing chain clearance.
The 1996 4.3L Vortec V-6 engine was updated with an upper balance shaft. The changes to the face of the engine block required a new, and taller, timing cover. This timing cover made provision for the CKP sensor that is used to receive an engine position signal from the 3x crankshaft reluctor.
ECM, distributor, and ignition coil.
3x GM reluctor and 3x EFI Connection reluctor.
Plastic Vortec timing cover and TPIS billet small-block timing cover.
Those with an early 4.3L V-6 are not able to use the GM plastic Vortec timing cover because the upper portion of the cover does not seal to the early engine block. Fortunately the early 4.3L V-6 engines share the same timing cover as Gen I small-block engines. For CKP sensor provision for early 4.3L engines, the TPIS billet-aluminum small-block timing cover provides the best fitment while properly sealing to the face of the engine block.
The GM# 12200411 PCM controls the six fuel injectors in sequential fire (not batch fire) mode. This means individual control of the fuel injectors. With the requirement of six fuel injectors, this newer PCM cannot be used with TBI units.
Early 4.3L TBI engines must receive a multi-port injection intake manifold upgrade so that six fuel injectors may be used. This requirement may be filled by sourcing a used Syclone or Typhoon intake manifold, aftermarket or custom manifold, or upgrading to Vortec cylinder heads and a production GM intake manifold. An attractive option for 4.3L engines using Vortec cylinder heads is the 4.3L marine manifold because it features external fuel injectors and a Gen III 3-bolt type throttle body.
The Syclone/Typhoon, Vortec truck, and LS-series throttle body TPS and IAC engines are directly compatible with this PCM. In fact, so are the ECT, IAT, and MAP sensors used with these V-6 and V-8 engines. The only remaining sensors to add are knock sensors, heated O2 sensors, optional MAF sensor, CMP sensor, and CKP sensor.
Single Coil and Distributor Ignition
The GM# 12200411 PCM was only used with the 4.3L V-6 engines in a single coil and distributor configuration. General Motors wrote the calibration software to expect 3x crankshaft and 1x camshaft signals for engine operation. This PCM uses the 3x crankshaft signal (and other engine sensor inputs) to control the ignition spark advance through the Vortec ignition module and single coil.
It may seem that by providing a higher-resolution crankshaft signal (such as a 24x LS-series crankshaft signal), the PCM controls one coil per cylinder but it simply does not work that way. GM’s 24x encoded signal is mapped for V-8 engines only. Had General Motors released a PCM calibration that supported coil-per-cylinder ignition for the V-6, an appropriate crankshaft reluctor with increased tooth count (higher resolution) could be installed to eliminate single coil and distributor ignition. What General Motors has provided, however, is no disappointment.
Tuning software, such as EFILive, delivers the same tuning benefi ts that sell us on the use of the Gen III PCM for LS-series engines as it does for V-6 engines. Through the same calibration tables and parameters, the same tuning software and hardware, and the same tuning techniques, this PCM is a fantastic engine controller for any 4.3L V-6 engine.
Iron marine intake manifold.
Vortec ignition module and coil.
Intake Manifold
Vortec cylinder heads are plentiful in the boneyards and offer excellent performance gain compared to the early 4.3L cylinder heads. The lower Syclone and Typhoon intake manifold may be modified to accommodate the raised intake runners of the Vortec cylinder heads. Rather than machine the Syclone or Typhoon intake manifold for the Vortec head bolt pattern, the Vortec heads can be drilled for the early 4.3L V-6 bolt pattern to create a better seal and clamping force.
3x Crankshaft Reluctor
The 3x crankshaft reluctor installs on the crankshaft and is firmly held in place between the crankshaft timing sprocket and crankshaft balancer. GM’s 3x crankshaft reluctor fully seats against the crankshaft timing sprocket only when using a single roller timing chain. Double roller timing chain installations require EFI Connection’s 3x crankshaft reluctor.
EFI Connection’s 3x crankshaft reluctor, double roller timing chain, and front Engine.
Vortec Distributor Assembly
The 1996-newer 4.3L V-6 distributor assembly installs in the traditional distributor location and is used to provide a 1x camshaft signal to the PCM. The PCM uses this camshaft signal to determine intake or exhaust stroke for any given cylinder during engine operation.
Vortec distributor installed in engine.
Written by Mike Noonan and Posted with Permission of CarTechBooks
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