spark control module, or no spark control module?

[1-ton]

My 1991 V3500 Crew Cab with 5.7 (TBI), 4L80E appears not to have a Spark Control Module. The ECM/PCM in it is a PN#16147060. I believe this ECM/PCM was the first year, which came with built in Spark Control. I am just trying to confirm this because I am going to replace the engine bay wiring harness with one from Howell Fuel Injection. This company is the only one that makes an engine bay wiring harness for my odd-ball 1991 V3500.

 

[Twiztedmods]

Factory 5.7? I know some 454's didn't have the Spark Control Module. I had an 87 V30 that didn't have it.

 

[Team208Motorsports]

On early TBI ECMs with dual black plugs, the module is always external. GVW and engine is what determines if there is a module or not.

The difference would be if the system uses burst knock or knock sensors and feed back. A module will have sensors. Burst knock is a set amount of timing added/subtracted from timing table depending on engine conditions.

 

[1-ton]

My 7060 ECM has the Tan colored connector terminals. This truck has a knock sensor, but that is all I know about that. The GVWR on my V3500 is about 9,850. I think the type of ECM/PCM a truck comes with is the main determining factor for coming equipped with a Spark Control Module. The older GM 7747 ECM is one that needs a Spark Control module.

 

[Team208Motorsports]

Well the 7060 changes my statement. Lol.

 

[1-ton]

thought I would bring this back to the top just one more time just to see if anyone happen to know an answer to this question. I know this is a complicated question, which delves deep into to rarely known knowledge.

 

[Team208Motorsports]

Knock sensor goes straight to PCM, so the module would be on board.

 

[Keitha]

14167060 does have spark controll. Easy way to verify is unplug the single tan wire while watching a timing gun - your timing should drop to 0.

 

[1-ton]

Thanks guys. I am guessing there was supposed to be a wiring diagram posted showing the Knock sensor running straight to the ECM/PCM instead of the Spark Control Module, but it did not load properly. That's OK, I get the idea. One thing I need to figure out is where that TAN wire ties into my new wiring harness. Howell Fuel Injections harness is only the ECM/PCM sensor harness, which does not include the charging, starting, headlight, or AC system. I think that the Tan wire starts out at the starter solenoid as a Purple wire, and then runs to a 3-AMP fuse at the fuse block. Which then comes out of the fuse block as a Tan wire running to the ECM/PCM. I am not positive, but I think this Tan wire is the power wire for the ECM/PCM, and it connects into the sensor wiring harness at a multiple junction somewhere.