LS1 No Start
04-26-2013, 10:40 PM
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LS1 No Start First of all, the LS1 is in a rx7...it's not a brand new swap and it has been running well for me for the past year until a few weeks ago.
Car cranks over just fine (IE - starter engages, motor turns, etc.) My problem is no spark.
At first...it would intermittently start. Would have to turn the key 3-5 times sometimes before it eventually started. Other times, it would start first try. Then one day while driving, it just started dying. Would push clutch in, rev it, would come back alive.
Currently, it will not start at all. When trying to start it, I get no RPM reading on my gauge, which points to a CKP issue, but as you can see below, I have gone over all of that.
What I've checked so far:
new NGK tr55 plugs and all my plug wires have ~30 ohms
Get ground from block to shock tower and ground from negative battery terminal to shock tower (everything is grounded)
All my fuses are good
Blue and red pins 1 and 40 are grounded.
Blue pins 20 and 57 have 12v constant
Blue pin 19 has 12v ignition
CKP Pins (Blue 2, 12, 21) have continuity between CKP connector and PCM connector
New CKP
Swapped my PCM into a buddies Transam, started right up first try
Coil pack harness pink wire has 12v, black wire is grounded. Individual coil packs also have 12v and ground, yet i'd assume they just arent getting the signal to fire.
I can hear the fuel pump and regulator gauge right before fuel rail shows ~60psi
Currently have the intake pulled to check MAP and Cam sensor, yet i don't think they contribute to spark issues.
Another weird thing is that my Kenwood radio receiver wont turn on. This happened as my car wouldn't start. No coincidence here. My Jeep also has a Kenwood deck, so i stuck the RX7 deck into the jeep and it powers up, so the receiver isn't dead. It only needs 2 wires, possibly 3 to turn on. It has the 12v constant to keep radio memory, ground, and ignition 12v. I've probed them all and they all check out. So I'm not sure as to why the Kenwood deck won't turn on in the Rx7 but will in the Jeep.
Car cranks over just fine (IE - starter engages, motor turns, etc.) My problem is no spark.
At first...it would intermittently start. Would have to turn the key 3-5 times sometimes before it eventually started. Other times, it would start first try. Then one day while driving, it just started dying. Would push clutch in, rev it, would come back alive.
Currently, it will not start at all. When trying to start it, I get no RPM reading on my gauge, which points to a CKP issue, but as you can see below, I have gone over all of that.
What I've checked so far:
new NGK tr55 plugs and all my plug wires have ~30 ohms
Get ground from block to shock tower and ground from negative battery terminal to shock tower (everything is grounded)
All my fuses are good
Blue and red pins 1 and 40 are grounded.
Blue pins 20 and 57 have 12v constant
Blue pin 19 has 12v ignition
CKP Pins (Blue 2, 12, 21) have continuity between CKP connector and PCM connector
New CKP
Swapped my PCM into a buddies Transam, started right up first try
Coil pack harness pink wire has 12v, black wire is grounded. Individual coil packs also have 12v and ground, yet i'd assume they just arent getting the signal to fire.
I can hear the fuel pump and regulator gauge right before fuel rail shows ~60psi
Currently have the intake pulled to check MAP and Cam sensor, yet i don't think they contribute to spark issues.
Another weird thing is that my Kenwood radio receiver wont turn on. This happened as my car wouldn't start. No coincidence here. My Jeep also has a Kenwood deck, so i stuck the RX7 deck into the jeep and it powers up, so the receiver isn't dead. It only needs 2 wires, possibly 3 to turn on. It has the 12v constant to keep radio memory, ground, and ignition 12v. I've probed them all and they all check out. So I'm not sure as to why the Kenwood deck won't turn on in the Rx7 but will in the Jeep.
Last edited by usmcpi; 04-26-2013 at 11:07 PM.
04-27-2013, 01:19 AM
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Someone wanna help me out and go unplug their TPS and see if car starts or has RPM reading while trying to start?
I have this: http://www.jegs.com/p/Caspers-Electr...57621/10002/-1 All the reviews I read about it says it works and voltage is boosted a good 2v under WOT, thus headlights getting brighter. Mine still got dim, along with the radio cutting off at WOT. So if this box has gone bad, thus preventing a TPS signal from getting through...
I would test it myself and remove it and try to start the car, but my intake mani and starter are off.
I have this: http://www.jegs.com/p/Caspers-Electr...57621/10002/-1 All the reviews I read about it says it works and voltage is boosted a good 2v under WOT, thus headlights getting brighter. Mine still got dim, along with the radio cutting off at WOT. So if this box has gone bad, thus preventing a TPS signal from getting through...
I would test it myself and remove it and try to start the car, but my intake mani and starter are off.
04-27-2013, 03:06 AM
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Someone wanna help me out and go unplug their TPS and see if car starts or has RPM reading while trying to start?
I have this: http://www.jegs.com/p/Caspers-Electr...57621/10002/-1 All the reviews I read about it says it works and voltage is boosted a good 2v under WOT, thus headlights getting brighter. Mine still got dim, along with the radio cutting off at WOT. So if this box has gone bad, thus preventing a TPS signal from getting through...
I would test it myself and remove it and try to start the car, but my intake mani and starter are off.
I have this: http://www.jegs.com/p/Caspers-Electr...57621/10002/-1 All the reviews I read about it says it works and voltage is boosted a good 2v under WOT, thus headlights getting brighter. Mine still got dim, along with the radio cutting off at WOT. So if this box has gone bad, thus preventing a TPS signal from getting through...
I would test it myself and remove it and try to start the car, but my intake mani and starter are off.
I say stop pulling **** apart!!! The radio is the clue to follow. I'm not very very schooled on the LS1 but..... KISS.... If the radio stopped working the same time you have no spark quite simply look for what they have in common
04-27-2013, 05:29 AM
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I had to pull the start back off to check the continuity between CKP sensor and the PCM pins. Pulled intake mani off to do the same thing with the MAP and Cam sensor. I also have extra sensors laying around so was gonna throw those in.
Well I didn't wire the car, I have no idea what they have in common :-/ But like i said, The radio harness probes out good with my meter. No idea why the radio won't turn on.
Well I didn't wire the car, I have no idea what they have in common :-/ But like i said, The radio harness probes out good with my meter. No idea why the radio won't turn on.
05-30-2013, 02:01 PM
#6
So did the Crank Shaft Position sensor continuity check good......
If you get no rpm reading on a scanner......it's a bad Crank Shaft Position sensor. Or of course it can be the PCM also or a combo of both.
Also.......even if the Crank Shaft sensor is new......get another one. People have purchased NEW "bad" sensors many times.....
.
If you get no rpm reading on a scanner......it's a bad Crank Shaft Position sensor. Or of course it can be the PCM also or a combo of both.
Also.......even if the Crank Shaft sensor is new......get another one. People have purchased NEW "bad" sensors many times.....
.
05-30-2013, 04:32 PM
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Yes, read checked list. I also have voltage coming from CKP to PCM. Although it was only getting 7-8v instead of the 10ish it should get. Can't possibly be the PCM when it started my friends car...again, read checked list
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06-04-2013, 01:57 PM
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did you pull a plug wire and have someone turn it over
and physically see if you have spark?
get a diode tester to plug fuel injector connector into
and see if you has injector pulse.
lets try and narrow it down between fuel and fire.
and physically see if you have spark?
get a diode tester to plug fuel injector connector into
and see if you has injector pulse.
lets try and narrow it down between fuel and fire.
06-07-2013, 10:09 AM
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Thanks for the suggestion LS6427...seems to test good though:
Got a CKP connector pigtail. Connected 12v from battery to pin C, grounded pin B and attached black multimeter lead to it and attached red lead to pin A. Turned car over by hand. Went 0-12v-0-12v-0, etc. Plugged my old stock CKP into my test set up and it did the same thing when i touched it to metal and pulled it away. Sounds normal right?
So went back and retested my PCM blue pins. They had all previously checked good, even while cranking. Pin 19 has 12v with ignition on as it should. Still good. Checked pins 20 and 57 again which are supposed to have 12v constant. They now have 0.6v with IGN OFF and 2.2v with IGN ON...
What the hell would cause this much voltage drop?
Got a CKP connector pigtail. Connected 12v from battery to pin C, grounded pin B and attached black multimeter lead to it and attached red lead to pin A. Turned car over by hand. Went 0-12v-0-12v-0, etc. Plugged my old stock CKP into my test set up and it did the same thing when i touched it to metal and pulled it away. Sounds normal right?
So went back and retested my PCM blue pins. They had all previously checked good, even while cranking. Pin 19 has 12v with ignition on as it should. Still good. Checked pins 20 and 57 again which are supposed to have 12v constant. They now have 0.6v with IGN OFF and 2.2v with IGN ON...
What the hell would cause this much voltage drop?
06-07-2013, 01:51 PM
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Never mind, I'm an idiot...it was because of one of the connectors behind the dash I unplugged when I pulled the dash out. PCM still has power. Why they had any voltage...I have no clue.
06-07-2013, 09:06 PM
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no need for a scope...you can do it by hand. Put 12 volts on PCM Blue 2, Volt test across pins 12 (CKP ground) and 21 (CKP reference signal). Turn engine over by hand and I get 12v - 0v - 12v - 0v etc. So the signal is getting between the PCM and CKP.
