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Discussion Starter · #1 ·
I just recently installed a set of 1.6 roller rockers on my 84 and now seem to be having an issue with what appears to be the ESC or knock sensor. I get a noticeable stumble or cut out like the system is retarding the timing real hard or just cutting it off like some plugs are not firing. (I already replaced the plugs, wires, cap and rotor, and tried a new distributor with the exact same results) I just recently read that GM had to revise their knock sensor because the old ones were too sensitive and was wondering if anyone else had a problem similar to this, and or if anyone had the part number to the revised knock sensor.

James
 

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I may be wrong, but I didn't think the 1984 Corvette engine had a knock sensor.

The addition of a knock sensor for the engine management system in 1985 allowed an increase in compression and a more aggressive spark timing map in the ECM.

As a result power increased for the 1985 models to 230 hp from the 205 hp rating in 1984.
 

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Discussion Starter · #3 ·
Yeah, the 84 has a knock sensor. The only difference between the 84 and the 85 is the intake. The 84 has the dual throttle body Crossfire intake and the 85 has the tuned port injection system. Both years have 9:1 compression. The reason for the horsepower increase was the much better flowing TBI setup. The CFI intake is very restrictive and doesn't allow the L83 to breath well above 4000 RPM.
 

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Will the LT-4 spark module fit an L-83 ECM setup? :huh:

I know on the LT-1 engines it enables a more aggressive spark advance and has plug-and-play interchangeability.
 

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Discussion Starter · #5 ·
Will the LT-4 spark module fit an L-83 ECM setup? :huh:

I know on the LT-1 engines it enables a more aggressive spark advance and has plug-and-play interchangeability.
I'm not sure.... I know that on the 84 there is an ESC (Electronic Spark Control Module) that works in conjunction with the knock sensor to monitor spark advance and retard, but I am not sure whether or not an LT-1 / LT-4 sensor would work correctly.
 

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Just for kicks, did you ask this same question on "another" forum? I wrote a reply to a very similar post, but I'm too lazy to re-type it here. (Feel free to ask on this forum for any clarification to that other post.)
 

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Will the LT-4 spark module fit an L-83 ECM setup? :huh:

I know on the LT-1 engines it enables a more aggressive spark advance and has plug-and-play interchangeability.
The LT4 module plugs into the ECM, whereas the '84 module is a standalone module that mounts under the hood. They also require different sensors due to differences in the internal circuitry.
 

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Discussion Starter · #8 ·
Just for kicks, did you ask this same question on "another" forum? I wrote a reply to a very similar post, but I'm too lazy to re-type it here. (Feel free to ask on this forum for any clarification to that other post.)
Yeah, I asked this on a couple of forums. Hopefully I'll get this problem resolved. I don't want to go out a buy a new sensor just to have it do the same thing. Hoping to find someone else that may have had the same problem.
 
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