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Dr. Theopolis
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Discussion Starter · #1 ·
My car is throwing code 42, EST. It stumbles, dies and runs not so good. I checked the calpak and PROM and made sure they are seated good. Checked the EST and BYPASS circuit connections on the ECM.

What else should i check?

Thanks, Scott

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86 GN, Blue Tops, TA-49, LT1 valve springs, 8Pos MaxEffort, 2 3/4" ATR DP, ported elbow, Adj FPR, Adj wastegate, Walbro 307 (hot wired), tie down strap, K+N, test pipe, Kenne Bell 2 1/2" dual exhaust, 160 stat, Nitto DR's, Directscan, Compaq laptop, Alky inj., Pro Torque 2800 stall in another working trans (#5 and counting)


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Dr. Theopolis
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Discussion Starter · #3 ·
Will that being loose cause problems, Steve?

Scott

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86 GN, Blue Tops, TA-49, LT1 valve springs, 8Pos MaxEffort, 2 3/4" ATR DP, ported elbow, Adj FPR, Adj wastegate, Walbro 307 (hot wired), tie down strap, K+N, test pipe, Kenne Bell 2 1/2" dual exhaust, 160 stat, Nitto DR's, Directscan, Compaq laptop, Alky inj., Pro Torque 2800 stall in another working trans (#5 and counting)


Minimalism (its the least you can do)
 

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Dr. Theopolis
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Discussion Starter · #5 ·
will that cause the car to die?
Scott

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86 GN, Blue Tops, TA-49, LT1 valve springs, 8Pos MaxEffort, 2 3/4" ATR DP, ported elbow, Adj FPR, Adj wastegate, Walbro 307 (hot wired), tie down strap, K+N, test pipe, Kenne Bell 2 1/2" dual exhaust, 160 stat, Nitto DR's, Directscan, Compaq laptop, Alky inj., Pro Torque 2800 stall in another working trans (#5 and counting)


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One of the nice things about TL is the connector right into the ADLD or what ever that deal is called. However I wonder if Ken has explored the windows option for the software and a little more real time data updates.
 

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from: http://www.gnttype.org/maint/malf.html#42

CODE 42

Trouble Code 42 indicates that there may be a malfunction in the Electronic Spark Timing (EST) system.

During cranking, the timing is controlled by the ignition module while the ECM monitors the engine speed. When the engine speed exceeds 400 RPM, the ECM sends a BYPASS signal to the ignition module which switches the timing to ECM control. The ECM calculates what the timing should be then "tells" the ignition module via the EST circuit.

An open or ground in the EST circuit will stall the engine and set a Code 42. The engine can be re-started but it will run on ignition module timing.

The conditions for setting this code are:

System in BYPASS mode but the ignition module is still controlling timing

- or -
Engine speed > 600 RPM with no EST pulses (ECM controlled timing) going to the ignition module for 200 msec.

Typical causes for this code include:

1) BYPASS line is open or grounded
2) EST line is open or grounded
3) PROM or CALPACK not seated properly in the ECM
4) Poor connections between ignition module and ECM
5) Poor routing of EST harness and/or poor quality ignition wires (EMI induced electrical noise)
6) Faulty or incorrect ignition module
7) Faulty ECM
 

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All the scan tools that use the aldl port are limited to the output frame rate. DS uses the engineering test port on the board so it can produce faster data rates.

Salvage, I believe, posted the color codes and terminal locations of the est line and the other one a few months ago. It will be in the archives if the bad ground is not the problem...the grounding of the module. I know about this one as I just fixed one that was running terribly and throwing code 42.
I could move the coil when I started to pull the plug wires.



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Dr. Theopolis
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Discussion Starter · #10 ·
I checked the EST and bypass ckts, and they were not grounded. But i think the DS plug was pushed all the way in on one side. How do you keep it from working its way back in when it rests on the ECM trim cover?

Scott

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86 GN, Blue Tops, TA-49, LT1 valve springs, 8Pos MaxEffort, 2 3/4" ATR DP, ported elbow, Adj FPR, Adj wastegate, Walbro 307 (hot wired), tie down strap, K+N, test pipe, Kenne Bell 2 1/2" dual exhaust, 160 stat, Nitto DR's, Directscan, Compaq laptop, Alky inj., Pro Torque 2800 stall in another working trans (#5 and counting)


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I took a Dremel tool and cut the plastic ECM housing so the connector can "fall thru". Now the ECM is not pushing on the connector and I have no more 42s.
 

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Dr. Theopolis
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Discussion Starter · #12 ·
Good idea! I will give it a try.

Thanks everyone for the help. Now can anyone help me with my 60' times?

Scott

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86 GN, Blue Tops, TA-49, LT1 valve springs, 8Pos MaxEffort, 2 3/4" ATR DP, ported elbow, Adj FPR, Adj wastegate, Walbro 307 (hot wired), tie down strap, K+N, test pipe, Kenne Bell 2 1/2" dual exhaust, 160 stat, Nitto DR's, Directscan, Compaq laptop, Alky inj., Pro Torque 2800 stall in another working trans (#5 and counting)


Minimalism (its the least you can do)
 

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