Lt1 runs, then wont start back up!
01-30-2017, 09:23 PM
#1
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Join Date: Mar 2015
Posts: 77
Lt1 runs, then wont start back up!
Fresh top end rebuild, Solomon tune. Start car up runs and idles great, shut car off after running for 1 min. Then try to start it up again and it just turns over but doesn't start. Has good fuel pressure. Go to start it up the next day and it fires right back up! What could be causing this? Optispark wouldnt do this would it? Its a brand new skip white opti with the original Mitsubishi sensor installed from my stock opti.
Also i do not have my radiator or waterpump hooked up, could the pcm be sensing this and not letting the car start back up do to lack of all of the sensors hooked up?
Also i do not have my radiator or waterpump hooked up, could the pcm be sensing this and not letting the car start back up do to lack of all of the sensors hooked up?
Last edited by Midnight_Z; 01-30-2017 at 09:25 PM. Reason: Adding more content
02-15-2017, 09:22 PM
#3
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Join Date: Mar 2015
Posts: 77
Re: Lt1 runs, then wont start back up!
Must have been the coolant sensor on the wp not being hooked up. Once i got that hooked up, radiator, and ewp it runs great and starts right back up. Makes sense, if the pcm isnt getting a coolant reading it should cut spark. Ohh and no codes.
02-16-2017, 11:16 AM
#4
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Location: Hell was full so they sent me to NJ
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Re: Lt1 runs, then wont start back up!
No it doesn't cut spark, per the factory manual. If you were driving down the road, and the coolant temp sensor failed, or the connector fell off, and the engine stopped, it would be a bit dangerous. If the coolant temp sensor fails, the PCM turns on both fans, and if it's an auto trans car, TCC will apply early.
Just a coincidence. The PCM does look at the CLT sensor to see how rich to set the cold start mixture, but with a code set, it defaults to programmed settings. If the engine warmed up a bit, and the PCM was still using a very rich mixture, might delay starting.
Just a coincidence. The PCM does look at the CLT sensor to see how rich to set the cold start mixture, but with a code set, it defaults to programmed settings. If the engine warmed up a bit, and the PCM was still using a very rich mixture, might delay starting.
Last edited by Injuneer; 02-16-2017 at 11:22 AM.
02-21-2017, 12:03 PM
#5
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Join Date: Mar 2015
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Re: Lt1 runs, then wont start back up!
Makes sense. So i started my car today as its just about ready to hit the road. And it started right up but now refuses to idle lol. Idles slightly rough at 1500-2500rpm but the minute i let off the gas and try to let it idle at 900-1k it just stalls.
Now a week ago it ran perfect in the garage for 15min, got up to temp fans turned on and everything was great. And it idled great, maybe a very slight hint of surge up and down a hundred rpm but not really noticeable.
Only thing that has changed since that 15min warm up is...........i put the k&n air filter on after spraying it lightly with the k&n oil the night before. And i added thermo paste behind my ICM for good heat transfer. This problem is very annoying!
Now a week ago it ran perfect in the garage for 15min, got up to temp fans turned on and everything was great. And it idled great, maybe a very slight hint of surge up and down a hundred rpm but not really noticeable.
Only thing that has changed since that 15min warm up is...........i put the k&n air filter on after spraying it lightly with the k&n oil the night before. And i added thermo paste behind my ICM for good heat transfer. This problem is very annoying!
02-21-2017, 03:14 PM
#6
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Join Date: Dec 2015
Location: St. Paul, MN
Posts: 194
Re: Lt1 runs, then wont start back up!
Just a thought, did you double check all the fits on everything when you put the K&N back on. If you removed the connection of the elbow from the throttle body and didn't get it back on for a good seal (I always check mine with a mirror) you may have a leak there, or have a vacuum line disconnected or loose.
Sounds like just rechecking what you touched or moved may be the answer.
Sounds like just rechecking what you touched or moved may be the answer.
07-18-2020, 12:44 PM
#8
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Join Date: Jul 2020
Location: San Diego
Posts: 3
Re: Lt1 runs, then wont start back up!
Fresh top end rebuild, Solomon tune. Start car up runs and idles great, shut car off after running for 1 min. Then try to start it up again and it just turns over but doesn't start. Has good fuel pressure. Go to start it up the next day and it fires right back up! What could be causing this? Optispark wouldnt do this would it? Its a brand new skip white opti with the original Mitsubishi sensor installed from my stock opti.
Also i do not have my radiator or waterpump hooked up, could the pcm be sensing this and not letting the car start back up do to lack of all of the sensors hooked up?
Also i do not have my radiator or waterpump hooked up, could the pcm be sensing this and not letting the car start back up do to lack of all of the sensors hooked up?