Ls3 c5
Thread Starter
Melting Slicks
Joined: Mar 2001
Posts: 3,251
Likes: 48
From: Parkland Florida
Corvette Challenge Champ-01
Dragster Challenge Champ-06
Ls3 c5
Two years ago we put in a 376/525 LS3 crate engine from Jegs. Have drag raced it ever since with no issues. I drive my car to the dragstrip race it and drive it home. On the way home about a week ago it just shut down on the highway. No check engine lights. Tried starting it just cranked. Called AAA towed me home. Scanned it no stored codes. Thought it might be the Lingenfelter conversion box TRG-002. Ordered a new one installed it cranked right up. Drove it home from the shop. Stalled about 2 miles from home. Waited to be towed. After about 35 minutes decided to pull the fuel pump relay out of the fuse block located next to the battery. Reinstalled it cranked right up. Still chasing this gremlin. Anyone have any ideas? Thanks.
Moderator, Tech Contributor
Joined: Sep 2013
Posts: 15,631
Likes: 4,076
From: Cape Coral, Florida
Hi Bob !!...it may be a crank sensor and a way to diagnose it is to see if you have any Tach movement during cranking...if you have a fuel pressure gauge turn the key to ON...see what your fuel pressure is....if the fuel pressure drops like a rock during cranking that’s another thing you can look at...I see your in Union...if you want to bring the car down to Monmouth County I can take a look at it but if it starts normally there is really nothing to check !!...if I think it’s a CKP I just hook up the scope to check the signal wire !!...oh, you can also turn the key ON and see if you can hear the fuel pump prime.
Rob
Rob
Last edited by C5 Diag; Sep 3, 2019 at 07:54 PM.
Thread Starter
Melting Slicks
Joined: Mar 2001
Posts: 3,251
Likes: 48
From: Parkland Florida
Corvette Challenge Champ-01
Dragster Challenge Champ-06
Hi Bob !!...it may be a crank sensor and a way to diagnose it is to see if you have any Tach movement during cranking...if you have a fuel pressure gauge turn the key to ON...see what your fuel pressure is....if the fuel pressure drops like a rock during cranking that’s another thing you can look at...I see your in Union...if you want to bring the car down to Monmouth County I can take a look at it but if it starts normally there is really nothing to check !!...if I think it’s a CKP I just hook up the scope to check the signal wire !!
Rob
Rob
Last edited by Turbo Bob; Sep 3, 2019 at 08:04 PM.
Thread Starter
Melting Slicks
Joined: Mar 2001
Posts: 3,251
Likes: 48
From: Parkland Florida
Corvette Challenge Champ-01
Dragster Challenge Champ-06
Yes original fuel pump. It almost seems heat related. When it cools down it will start and run fine.
Moderator, Tech Contributor
Joined: Sep 2013
Posts: 15,631
Likes: 4,076
From: Cape Coral, Florida
If the Tach does NOT move it may be a crank sensor...if a bad crank sensor you will have no spark or injection pulse...pull a plug wire off a coil and see if the spark jumps...to check injection pulse connect a test light to battery POSITIVE...remove an easy injector connector...while cranking probe the striped wire...the 12 volt test light will blink dimly if you have injection pulse...no spark...no injection pulse...NO START !!
Thread Starter
Melting Slicks
Joined: Mar 2001
Posts: 3,251
Likes: 48
From: Parkland Florida
Corvette Challenge Champ-01
Dragster Challenge Champ-06
If the Tach does NOT move it may be a crank sensor...if a bad crank sensor you will have no spark or injection pulse...pull a plug wire off a coil and see if the spark jumps...to check injection pulse connect a test light to battery POSITIVE...remove an easy injector connector...while cranking probe the striped wire...the 12 volt test light will blink dimly if you have injection pulse...no spark...no injection pulse...NO START !!
Moderator, Tech Contributor
Joined: Sep 2013
Posts: 15,631
Likes: 4,076
From: Cape Coral, Florida
You can swap the fuel pump relay with the horn relay...see if the car runs ok...like I said see if you have a 2 second prime on the fuel pump with key on...I did a YouTube video on testing the fuel pump relay circuit if it comes down to that...I usually scope the pump and check current flow and RPM !!
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Racer
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From: Montana
The TRG-002 has troubleshoot indicators... with red or green light flashing.
Light emitting diode (LED) STATUS light operation/diagnostic codes:
• Solid RED indicates powered on/no input signals present (normal for key on/engine off)
• Solid GREEN indicates the TRG-002 has a valid crankshaft and camshaft signal and is in
synchronized operation
• Blinking RED indicates no crankshaft signal in with a camshaft signal detected
• Check connections at the crankshaft sensor. Check the tachometer or the engine RPM with a scan tool while cranking the engine. If no RPM is shown while cranking then the TRG-002 is not outputting a crankshaft signal.
• Blinking GREEN indicates no camshaft signal in with a crank signal detected
• The engine should start but you may sometimes have to crank the engine for a long time before it starts. You most likely do not have a proper camshaft sensor signal into the TRG- 002. Check camshaft sensor connections and wiring pin-outs.
• The ECM/PCM should set a camshaft sensor DTC.
• Blinking RED RED RED GREEN (three red blinks followed by a green blink) indicates the TRG-002 lost crank synchronization and recovered
• Usually due to electrical noise or bad sensor/wiring.
• Blinking GREEN GREEN GREEN RED (three green blinks followed by a red blink) indicates a loss of camshaft signal.
• Usually due to electrical noise or bad sensor/wiring.
• The TRG-002 will blink either of these two last error codes on the three (3) power up cycles after the problem occurs. If the error does not occur again during those three power ups then the code will clear. If another code occurs prior to the code clearing, the older code will be cleared and the new code will be stored and displayed.
Light emitting diode (LED) STATUS light operation/diagnostic codes:
• Solid RED indicates powered on/no input signals present (normal for key on/engine off)
• Solid GREEN indicates the TRG-002 has a valid crankshaft and camshaft signal and is in
synchronized operation
• Blinking RED indicates no crankshaft signal in with a camshaft signal detected
• Check connections at the crankshaft sensor. Check the tachometer or the engine RPM with a scan tool while cranking the engine. If no RPM is shown while cranking then the TRG-002 is not outputting a crankshaft signal.
• Blinking GREEN indicates no camshaft signal in with a crank signal detected
• The engine should start but you may sometimes have to crank the engine for a long time before it starts. You most likely do not have a proper camshaft sensor signal into the TRG- 002. Check camshaft sensor connections and wiring pin-outs.
• The ECM/PCM should set a camshaft sensor DTC.
• Blinking RED RED RED GREEN (three red blinks followed by a green blink) indicates the TRG-002 lost crank synchronization and recovered
• Usually due to electrical noise or bad sensor/wiring.
• Blinking GREEN GREEN GREEN RED (three green blinks followed by a red blink) indicates a loss of camshaft signal.
• Usually due to electrical noise or bad sensor/wiring.
• The TRG-002 will blink either of these two last error codes on the three (3) power up cycles after the problem occurs. If the error does not occur again during those three power ups then the code will clear. If another code occurs prior to the code clearing, the older code will be cleared and the new code will be stored and displayed.
Thread Starter
Melting Slicks
Joined: Mar 2001
Posts: 3,251
Likes: 48
From: Parkland Florida
Corvette Challenge Champ-01
Dragster Challenge Champ-06
The TRG-002 has troubleshoot indicators... with red or green light flashing.
Light emitting diode (LED) STATUS light operation/diagnostic codes:
• Solid RED indicates powered on/no input signals present (normal for key on/engine off)
• Solid GREEN indicates the TRG-002 has a valid crankshaft and camshaft signal and is in
synchronized operation
• Blinking RED indicates no crankshaft signal in with a camshaft signal detected
• Check connections at the crankshaft sensor. Check the tachometer or the engine RPM with a scan tool while cranking the engine. If no RPM is shown while cranking then the TRG-002 is not outputting a crankshaft signal.
• Blinking GREEN indicates no camshaft signal in with a crank signal detected
• The engine should start but you may sometimes have to crank the engine for a long time before it starts. You most likely do not have a proper camshaft sensor signal into the TRG- 002. Check camshaft sensor connections and wiring pin-outs.
• The ECM/PCM should set a camshaft sensor DTC.
• Blinking RED RED RED GREEN (three red blinks followed by a green blink) indicates the TRG-002 lost crank synchronization and recovered
• Usually due to electrical noise or bad sensor/wiring.
• Blinking GREEN GREEN GREEN RED (three green blinks followed by a red blink) indicates a loss of camshaft signal.
• Usually due to electrical noise or bad sensor/wiring.
• The TRG-002 will blink either of these two last error codes on the three (3) power up cycles after the problem occurs. If the error does not occur again during those three power ups then the code will clear. If another code occurs prior to the code clearing, the older code will be cleared and the new code will be stored and displayed.
Light emitting diode (LED) STATUS light operation/diagnostic codes:
• Solid RED indicates powered on/no input signals present (normal for key on/engine off)
• Solid GREEN indicates the TRG-002 has a valid crankshaft and camshaft signal and is in
synchronized operation
• Blinking RED indicates no crankshaft signal in with a camshaft signal detected
• Check connections at the crankshaft sensor. Check the tachometer or the engine RPM with a scan tool while cranking the engine. If no RPM is shown while cranking then the TRG-002 is not outputting a crankshaft signal.
• Blinking GREEN indicates no camshaft signal in with a crank signal detected
• The engine should start but you may sometimes have to crank the engine for a long time before it starts. You most likely do not have a proper camshaft sensor signal into the TRG- 002. Check camshaft sensor connections and wiring pin-outs.
• The ECM/PCM should set a camshaft sensor DTC.
• Blinking RED RED RED GREEN (three red blinks followed by a green blink) indicates the TRG-002 lost crank synchronization and recovered
• Usually due to electrical noise or bad sensor/wiring.
• Blinking GREEN GREEN GREEN RED (three green blinks followed by a red blink) indicates a loss of camshaft signal.
• Usually due to electrical noise or bad sensor/wiring.
• The TRG-002 will blink either of these two last error codes on the three (3) power up cycles after the problem occurs. If the error does not occur again during those three power ups then the code will clear. If another code occurs prior to the code clearing, the older code will be cleared and the new code will be stored and displayed.
Thread Starter
Melting Slicks
Joined: Mar 2001
Posts: 3,251
Likes: 48
From: Parkland Florida
Corvette Challenge Champ-01
Dragster Challenge Champ-06
Update. Went to the shop this morning. My friend Mike hooked up spark plug tool and fuel pressure gauge. Drove it city and highway driving for approximately 20-25 miles. Brought a new fuel pump relay along just in case.Car did not miss a beat. Fuel pressure was at 60 lbs. Getting spark. Back to the shop. Checked the fuel pump relay in the fuse block next to the battery. It seemed hot but that may be normal with a just driven hot engine. Won’t leave there until we find the problem.
Last edited by Turbo Bob; Sep 4, 2019 at 01:07 PM.
Thread Starter
Melting Slicks
Joined: Mar 2001
Posts: 3,251
Likes: 48
From: Parkland Florida
Corvette Challenge Champ-01
Dragster Challenge Champ-06
Acct Suspended APR 2026 by request
Joined: Dec 2010
Posts: 10,367
Likes: 1,272
2020 Corvette of the Year Finalist (performance mods)
C5 of Year Winner (performance mods) 2019
if you have an old relay take it apart and get one of the legs and then remove your relay and insert the spare leg into each slot for the fuel pump relay... you should feel some resistance when pushing the leg into the slots, if it's loose then that could be an issue since it isn't making good contact... you can use a dab of solder on the relay legs to make them fit tighter or get another fuse box... I have seen the fuse box disassembled and it seems like a pita to try to fix it from the inside
Thread Starter
Melting Slicks
Joined: Mar 2001
Posts: 3,251
Likes: 48
From: Parkland Florida
Corvette Challenge Champ-01
Dragster Challenge Champ-06
if you have an old relay take it apart and get one of the legs and then remove your relay and insert the spare leg into each slot for the fuel pump relay... you should feel some resistance when pushing the leg into the slots, if it's loose then that could be an issue since it isn't making good contact... you can use a dab of solder on the relay legs to make them fit tighter or get another fuse box... I have seen the fuse box disassembled and it seems like a pita to try to fix it from the inside
1st Gear
Joined: Jul 2025
Posts: 1
Likes: 0
No start
Two years ago we put in a 376/525 LS3 crate engine from Jegs. Have drag raced it ever since with no issues. I drive my car to the dragstrip race it and drive it home. On the way home about a week ago it just shut down on the highway. No check engine lights. Tried starting it just cranked. Called AAA towed me home. Scanned it no stored codes. Thought it might be the Lingenfelter conversion box TRG-002. Ordered a new one installed it cranked right up. Drove it home from the shop. Stalled about 2 miles from home. Waited to be towed. After about 35 minutes decided to pull the fuel pump relay out of the fuse block located next to the battery. Reinstalled it cranked right up. Still chasing this gremlin. Anyone have any ideas? Thanks.