Wont Start After Engine Install
Thread Starter
Launching!
Joined: Dec 2004
Posts: 288
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From: California
Wont Start After Engine Install Odd situation, never had a problem prior to engine swap 
Just finished a grueling engine/Trans swap... & Now it wont start, pretty depressing...
Anyways, I scanned the PCM & it gives me the "P1637" L-Terminal, I researched this code up and down but didnt get much out of it besides looking at my alternator as the culprit. I inspected my alternator wires & they look fine... The only aspect of the wiring system im confused about is the ground(s) in the rear driver side head, there was a bunch of black wires that i assumed were Ground wires, so i screwd them in all together.
Now before digging back in the car i really wanted to make sure im looking in the correct places, sense many of the people on this board do this stuff ALL the time i wanted your expert advice.
Also i went to a performance shop in my area & the guy said that my cam sensor could be causing this problem sense he said, that the cam sensor is what tells my coil packs to create spark.... Ive never heard that before
Any suggestions/advise would be GREATLY appreciated!
Just finished a grueling engine/Trans swap... & Now it wont start, pretty depressing...
Anyways, I scanned the PCM & it gives me the "P1637" L-Terminal, I researched this code up and down but didnt get much out of it besides looking at my alternator as the culprit. I inspected my alternator wires & they look fine... The only aspect of the wiring system im confused about is the ground(s) in the rear driver side head, there was a bunch of black wires that i assumed were Ground wires, so i screwd them in all together.
Now before digging back in the car i really wanted to make sure im looking in the correct places, sense many of the people on this board do this stuff ALL the time i wanted your expert advice.
Also i went to a performance shop in my area & the guy said that my cam sensor could be causing this problem sense he said, that the cam sensor is what tells my coil packs to create spark.... Ive never heard that before
Any suggestions/advise would be GREATLY appreciated!
Last edited by TWISTEDTA; Sep 25, 2006 at 10:39 AM.
That code points to the generator which is located in the alternator. Make sure the small red wire is connected to the alternator via the plug on top. It's not unusual to break this wire during an engine swap because it's so small and easy to miss.
Some quick questions:
* Does the car even crank over? If so...
can you smell or detect unburnt gas when cranking?
* Any other DTC's showing up?
* What is the battery voltage at the terminal and the AUX post by the fuse box?
You're getting some mixed information. The vehicle can start with a bad cam sensor reading, but will not start with a bad crank sensor. The cam sensor helps determines TDC for the PCM. The signal from crank sensor drives the fuel injectors and coil packs; not the cam sensor. IF it was a bad cam sensor, the car would start but it would take excessive cranking to turn it over.
Some quick questions:
* Does the car even crank over? If so...
can you smell or detect unburnt gas when cranking?
* Any other DTC's showing up?
* What is the battery voltage at the terminal and the AUX post by the fuse box?
You're getting some mixed information. The vehicle can start with a bad cam sensor reading, but will not start with a bad crank sensor. The cam sensor helps determines TDC for the PCM. The signal from crank sensor drives the fuel injectors and coil packs; not the cam sensor. IF it was a bad cam sensor, the car would start but it would take excessive cranking to turn it over.
Thread Starter
Launching!
Joined: Dec 2004
Posts: 288
Likes: 0
From: California
Originally Posted by DrkPhx
That code points to the generator which is located in the alternator. Make sure the small red wire is connected to the alternator via the plug on top. It's not unusual to break this wire during an engine swap because it's so small and easy to miss.
Some quick questions:
* Does the car even crank over? If so...
can you smell or detect unburnt gas when cranking?
* Any other DTC's showing up?
* What is the battery voltage at the terminal and the AUX post by the fuse box?
You're getting some mixed information. The vehicle can start with a bad cam sensor reading, but will not start with a bad crank sensor. The cam sensor helps determines TDC for the PCM. The signal from crank sensor drives the fuel injectors and coil packs; not the cam sensor. IF it was a bad cam sensor, the car would start but it would take excessive cranking to turn it over.
Some quick questions:
* Does the car even crank over? If so...
can you smell or detect unburnt gas when cranking?
* Any other DTC's showing up?
* What is the battery voltage at the terminal and the AUX post by the fuse box?
You're getting some mixed information. The vehicle can start with a bad cam sensor reading, but will not start with a bad crank sensor. The cam sensor helps determines TDC for the PCM. The signal from crank sensor drives the fuel injectors and coil packs; not the cam sensor. IF it was a bad cam sensor, the car would start but it would take excessive cranking to turn it over.
Yes the car cranks over
& yes the i can smell the raw fuel
Im not sure about the voltage but ive even tried to start it with a battery charger connected to the battery it self.
No, no other codes, just that one.
Yea i inspected that wire, looks fine. I was thinking maybe its internal (Inside Alternator)? Or the crank sensor.... Im pretty sure if it were the crank sensor id have another code for it.
Thanks man
Have you checked for spark?
The crank sensor w/run the motor. But the cam sensor times the injector firing for sequential operation.
W/out the cam sensor it will run batch/bank fire on the injectors.
It will also set a code with out it.
The crank sensor w/run the motor. But the cam sensor times the injector firing for sequential operation.
W/out the cam sensor it will run batch/bank fire on the injectors.
It will also set a code with out it.
Originally Posted by TWISTEDTA
Hey thanks for your reply bro
Yes the car cranks over
& yes the i can smell the raw fuel
Yes the car cranks over
& yes the i can smell the raw fuel
I just did another rebuild and could not get the thing to start. Was really pissing me off because i couldn't figure it out. It turned out to be VATS, i turned that **** off w/HPT and it fired right up.
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Thread Starter
Launching!
Joined: Dec 2004
Posts: 288
Likes: 0
From: California
I checked all the grounds that i could see, they look a.o.k
Im running TR55 Plugs i believe... Its the hotter plug
I havent unplugged one though, i will do that next to ditermine if its even getting spark.
What is Vats? & if it were Vats, wouldnt it have a code?
Yea, it has perfect fuel pressure at this point. Im running 36 ible injectors. Its not the tune thats for sure, because even though its a new set up, it still has a tune from my last set up. Its going to need another due to the fact that this cam is alot bigger then the TR224
Thanks ALOT guys, i really, really appreciate the input.
Im running TR55 Plugs i believe... Its the hotter plug
I havent unplugged one though, i will do that next to ditermine if its even getting spark.
What is Vats? & if it were Vats, wouldnt it have a code?
Yea, it has perfect fuel pressure at this point. Im running 36 ible injectors. Its not the tune thats for sure, because even though its a new set up, it still has a tune from my last set up. Its going to need another due to the fact that this cam is alot bigger then the TR224
Thanks ALOT guys, i really, really appreciate the input.
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Thread Starter
Launching!
Joined: Dec 2004
Posts: 288
Likes: 0
From: California
Originally Posted by See5
I know a common problem on Vettes is the ground wire on the back of the driver's side head.
I really need a chart that shows every single ground wire and where it goes....Anybody know where i can find one?
Keep'em coming guys, thanks!
It doesn't matter were you bolt the grounds on the heads as long as you have them all bolted in. There is a ground strap that goes from the bottom of the block on the drivers side to the chassis just forward of the drivers side fender on the Fbodies. Not sure if you have that on the vette. Mine runs just under the alternator but you dont want it to touch the back post on the hot wire on the alternator ( i did this and melted the terminal on the battery). Perhaps the reluctor is not properly installed on the crank.
VATS= Vehicle Anti Theft System. I just did a tear down and went to a bigger cam too. I was racking my brain trying to figure out why it wouldn't start, opened up HPT and turned off VATS. Started right up.
Thread Starter
Launching!
Joined: Dec 2004
Posts: 288
Likes: 0
From: California
Yea that ground wires is on correctly, Im not very sure of the crank sensor yet. I Havent even had time to get back under that thing. I must addmit ive learned alot already ffrom this thread!
So my next step will be:
Check for spark
Check Crank sencor
Check Vats
Im not sure if it will do me any good because of the fact that im sure if it were any of these other possibilitys that were mentioned... wouldnt it have thrown more codes?
So my next step will be:
Check for spark
Check Crank sencor
Check Vats
Im not sure if it will do me any good because of the fact that im sure if it were any of these other possibilitys that were mentioned... wouldnt it have thrown more codes?
Last edited by TWISTEDTA; Aug 22, 2006 at 01:19 AM.
Thread Starter
Launching!
Joined: Dec 2004
Posts: 288
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From: California
Update I finally had a chance to take a look. I Cut the dinky red wire that plugs into the top of the alternator so i could extend it, just for a peace of mind, I read ALOT of bad storys about that little basterd.
Also i noticed the ground wire or power wire bolt on the rear side of the alternator was very lose so what i did, was just pulled the whole thing. Now i can inspect it carefully. Another thing, the engine ground that is located on the block next to the engine mount was missing the litte metal braket, Lucky for me i found it and installed it.
So tommorow i will tighten the power bolt, and sence its out, it wont hurt to get the thing tested.
Ill keep ya'll posted.
Thank you
Joe
Also i noticed the ground wire or power wire bolt on the rear side of the alternator was very lose so what i did, was just pulled the whole thing. Now i can inspect it carefully. Another thing, the engine ground that is located on the block next to the engine mount was missing the litte metal braket, Lucky for me i found it and installed it.
So tommorow i will tighten the power bolt, and sence its out, it wont hurt to get the thing tested.
Ill keep ya'll posted.
Thank you
Joe
Thread Starter
Launching!
Joined: Dec 2004
Posts: 288
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From: California
2nd update: Pulled alternator off & got it checked-It passed. Fixed the little RED wire (Extended it)
Checked for spark, had it.
Ran a DTC no codes left.... Yet, car still wont start.
With my set up (See SIG) im probley around 11:0.1 Compression, what should my spark plug gap be?
Im running out of ideas... No codes left, security light does not flash, so i really dought its VATS.
Thanks for all the help guys.
Joe
Checked for spark, had it.
Ran a DTC no codes left.... Yet, car still wont start.
With my set up (See SIG) im probley around 11:0.1 Compression, what should my spark plug gap be?
Im running out of ideas... No codes left, security light does not flash, so i really dought its VATS.
Thanks for all the help guys.
Joe
Teching In
Joined: Nov 2004
Posts: 35
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Originally Posted by TWISTEDTA
Pulled alternator off & got it checked-It passed. Fixed the little RED wire (Extended it)
Checked for spark, had it.
Ran a DTC no codes left.... Yet, car still wont start.
With my set up (See SIG) im probley around 11:0.1 Compression, what should my spark plug gap be?
Im running out of ideas... No codes left, security light does not flash, so i really dought its VATS.
Thanks for all the help guys.
Joe
Checked for spark, had it.
Ran a DTC no codes left.... Yet, car still wont start.
With my set up (See SIG) im probley around 11:0.1 Compression, what should my spark plug gap be?
Im running out of ideas... No codes left, security light does not flash, so i really dought its VATS.
Thanks for all the help guys.
Joe
does the car actually fire and run for a sec before cutting out?? or does it just keep on cranking and not fire at all
have you checked your compression with a guage?? what readings are you getting
Thread Starter
Launching!
Joined: Dec 2004
Posts: 288
Likes: 0
From: California
Originally Posted by SikHabibBroCuz
spark plug gap isnt critical to get the engine running. it may run ruff or miss if the gaps are way out but it will still run
does the car actually fire and run for a sec before cutting out?? or does it just keep on cranking and not fire at all
have you checked your compression with a guage?? what readings are you getting
does the car actually fire and run for a sec before cutting out?? or does it just keep on cranking and not fire at all
have you checked your compression with a guage?? what readings are you getting
but thats as far as it gets