Don't know where to start...
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From: Callahan, Fl
Don't know where to start... I have a GM Performance LS3/4L65e combo installed in a 67 Chevelle. Engine turns over but I have no spark or fuel pressure, what have I overlooked? Any insight/advice is welcome! Anyone in the N.E. Florida area want to come by? Beer & food awaits....
Cheers,
Geoff
Cheers,
Geoff
Thread Starter
Teching In
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From: Callahan, Fl
On The Tree
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From: Detroit, Michigan
Can you get a multi-meter on the fuel pump harness, key up, and see if you read 12v?
Anything is possible, the pump could be dead, best to see that the PCM is sending power to prime the pump.
Start with the basics right?
Anything is possible, the pump could be dead, best to see that the PCM is sending power to prime the pump.
Start with the basics right?
Thread Starter
Teching In
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From: Callahan, Fl
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From: Callahan, Fl
On The Tree
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From: Detroit, Michigan
I don't think you could verify it outside of pulling the calibration with HP Tuners or EFI Live or something similar.
The fact that there is no fuel pressure or spark makes me suspicious. I've had cars in the past where when the key wasn't recognized, it would still energize the starter and crank the engine, it just wouldn't fuel or energize the coils.
I still think checking the power to the pump is the place to start, if there's no power going to the pump then clearly it's a problem with wiring or calibration. If wiring is good, then I would suspect the problem lies within the PCM SW. The other possibility is that the key module isn't wired into the PCM correctly.
I don't have much experience with the GM Performance Kits if I'm being honest. Hopefully someone else can chime in.
The fact that there is no fuel pressure or spark makes me suspicious. I've had cars in the past where when the key wasn't recognized, it would still energize the starter and crank the engine, it just wouldn't fuel or energize the coils.
I still think checking the power to the pump is the place to start, if there's no power going to the pump then clearly it's a problem with wiring or calibration. If wiring is good, then I would suspect the problem lies within the PCM SW. The other possibility is that the key module isn't wired into the PCM correctly.
I don't have much experience with the GM Performance Kits if I'm being honest. Hopefully someone else can chime in.
On The Tree
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From: Detroit, Michigan
Compression, fuel, spark. Verify all those first. Fuel noid lights are handy for this and spark is easy as well as compression easy and fuel pressure easy. If all that checks out to sort through the wiring heres a simple guide;
All Orange wires are bat12v+BAT so you can check the pins and see what has orange and verify each is hot with the key off. All pink are 12v+IGN so you can check to see all those are hot with the key on ign. If all those check out you can check the grounds within the harness using a test light by using the positive term on the bat with the clip and the test light probe on the ground. If all that checks out on all fronts then you can verify the pins ( easy to do by color ) check the sensors and compare the colors to the PCM pins which you can find diagrams fro over at LS2swap
VATS related issues shouldn't be present if its a made for swap deal but you never know. I can tell you this much even though im not a tuner, buying HPtuners for swap related control alone is worth the money. There is an open source set up made by some board members here you could look into that might help but a handheld scan tool isnt going to help much if swapping LS motors is something you want to do more than one of. If its a one off? Find a good tuner who can sort out whats what and you can check most of the issues with wiring by verifying sensor function. Hope this is of some help
All Orange wires are bat12v+BAT so you can check the pins and see what has orange and verify each is hot with the key off. All pink are 12v+IGN so you can check to see all those are hot with the key on ign. If all those check out you can check the grounds within the harness using a test light by using the positive term on the bat with the clip and the test light probe on the ground. If all that checks out on all fronts then you can verify the pins ( easy to do by color ) check the sensors and compare the colors to the PCM pins which you can find diagrams fro over at LS2swap
VATS related issues shouldn't be present if its a made for swap deal but you never know. I can tell you this much even though im not a tuner, buying HPtuners for swap related control alone is worth the money. There is an open source set up made by some board members here you could look into that might help but a handheld scan tool isnt going to help much if swapping LS motors is something you want to do more than one of. If its a one off? Find a good tuner who can sort out whats what and you can check most of the issues with wiring by verifying sensor function. Hope this is of some help
Agree with the HP Tuner/EFI Live comment, even if you don't tune it you can see into it and that is invaluable, even if you don't know what your doing at least others can help. This is on the market place now
https://ls1tech.com/forums/market/1914481
Agree with Orange and Pink wire focus first to ensure the batt and ign power is proper. Grounds are a bitch I'd check quality of ground as well.
Past that I'd be focusing on why the pump does not trigger a prime on key on condition. I'd add stand alone power to the pump first to see if it is working, if it is you know you have a PCM or RELAY problem.... start with the relay and verify key on is triggering the relay. just keep working back from there, alot of times if you fix one thing you fix many.
Good luck, I feel your pain.
https://ls1tech.com/forums/market/1914481
Agree with Orange and Pink wire focus first to ensure the batt and ign power is proper. Grounds are a bitch I'd check quality of ground as well.
Past that I'd be focusing on why the pump does not trigger a prime on key on condition. I'd add stand alone power to the pump first to see if it is working, if it is you know you have a PCM or RELAY problem.... start with the relay and verify key on is triggering the relay. just keep working back from there, alot of times if you fix one thing you fix many.
Good luck, I feel your pain.
Grounds!!! Good catch yes of course how could I overlook stressing the importance of grounds. 99% of the time with auto electrical problems its ground related. Add more, the more the merrier.
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Teching In
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From: Callahan, Fl
Thanks for the insight/advise Cam,EPFATBOY and Ol Geezer! Have some work to do now, the ONLY thing I'm sure of is, it is grounded, haha
Last edited by Geoff1200; Feb 6, 2019 at 03:21 PM. Reason: oops