Start - Dies issue (beating a dead horse)
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Teching In
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Start - Dies issue (beating a dead horse) I have an 87 camaro z-28 that I have been working on a swap for,
(engine background)
I pulled a 4.8 out of a 2003 GMC Savana that ran (I drove it for 1.5 years) until one day it just stopped running out of the blue, would start then die, would stay running if you sprayed gas into the intake directly, but wouldn't stay running on it's own. I suspected it was a bad fuel pump, the van was rusty and had some other issues so I pulled the motor, trans and 100% of the wiring harness - minus headlight & tail light wiring.
I got it installed into my camaro, wiring harness was never removed from engine and includes original key/ignition. I replaced the fuel pump with a Walbro 255, replaced the fuel filter and FPR as well. From what I understand the likely issue is the Passlock system, I tried the "relearn" procedure both 10min and 30 min multiple times both, with no success, I have yet to check fuel pressure at the rail but am assuming it's fine with all the new parts (I will check once I get to town and can buy a test gauge)
engine still starts, runs for 1-2 sec and dies, maybe every 10th time it tries to keep going but never any longer than 2 more sec. I checked fuel injectors with noid light set and they never cut out like I would expect with passlock issue
I am lost on how to proceed further, and am beyond frustrated with this motor, please help
(engine background)
I pulled a 4.8 out of a 2003 GMC Savana that ran (I drove it for 1.5 years) until one day it just stopped running out of the blue, would start then die, would stay running if you sprayed gas into the intake directly, but wouldn't stay running on it's own. I suspected it was a bad fuel pump, the van was rusty and had some other issues so I pulled the motor, trans and 100% of the wiring harness - minus headlight & tail light wiring.
I got it installed into my camaro, wiring harness was never removed from engine and includes original key/ignition. I replaced the fuel pump with a Walbro 255, replaced the fuel filter and FPR as well. From what I understand the likely issue is the Passlock system, I tried the "relearn" procedure both 10min and 30 min multiple times both, with no success, I have yet to check fuel pressure at the rail but am assuming it's fine with all the new parts (I will check once I get to town and can buy a test gauge)
engine still starts, runs for 1-2 sec and dies, maybe every 10th time it tries to keep going but never any longer than 2 more sec. I checked fuel injectors with noid light set and they never cut out like I would expect with passlock issue
I am lost on how to proceed further, and am beyond frustrated with this motor, please help
Last edited by Dustin Fritz; Jun 29, 2015 at 02:11 PM. Reason: add info
Thread Starter
Teching In
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kept everything on the wiring harness including BCM, fuseboxes, as it was in the van, when I plug my scanner into the obd2 port it cant communicate with the vehicle, not sure what the deal is.
i have a feeling i need to completely tear down the wiring harness and eliminate everything that's not needed, and follow every wire to its proper location. But the haynes online manual i got doesn't have wiring for the PCM so i dont know how to even try to figure it out
i have a feeling i need to completely tear down the wiring harness and eliminate everything that's not needed, and follow every wire to its proper location. But the haynes online manual i got doesn't have wiring for the PCM so i dont know how to even try to figure it out
On The Tree
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your main issue of pursuit should be getting your scanner to communicate. That PCM from the truck has only one wire that's critical for PCM scanning and thats in the Blue Connector of the PCM pin 58. Pin 58 from PCM goes to Pin 2 of the OBD-2 Port.
Since you did the swap you should check for power in your OBD2 Port FIRST. Pin 16. If that doesn't have +12V at all times or even with key on then you need grab a +12v battery wire source and splice into that wire and get that fixed. Then attempt a rescan. If that still doesn't work then go on and check continuity between Pin 58 Blue PCM connector and Pin 2 OBD2 port.
Pins 4,5 of the OBD2 port are ground wires.
Since you did the swap you should check for power in your OBD2 Port FIRST. Pin 16. If that doesn't have +12V at all times or even with key on then you need grab a +12v battery wire source and splice into that wire and get that fixed. Then attempt a rescan. If that still doesn't work then go on and check continuity between Pin 58 Blue PCM connector and Pin 2 OBD2 port.
Pins 4,5 of the OBD2 port are ground wires.
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Thread Starter
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I'll work this week on troubleshooting the obd2 port first, since I'd like that to work anyways
Thank you so much for the info on which pins to look at... i'll report back and let you know what the scanner reads out
Thank you so much for the info on which pins to look at... i'll report back and let you know what the scanner reads out
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Starts, dies In addition to the scanner check for fuel and spark. You will need a noid light and use a timing light for spark. Also make sure you are maintaining fuel pressure. If it runs with spray I would say you have spark so look to fuel pressure and injectors firing even when running on spray.
Thread Starter
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took a step forward this evening, was able to track down the obd2 port wiring issue, that wire had accidently been disconnected, was able to get the reader to connect
codes that read out were evaporative emissions purge valve (which was an issue since day one of having the van) i found when i was pulling the motor that the purge valve wasn't seated properly...
all the other monitoring systems were ok, including the fuel system monitor, so that leads me to believe that it is likely a VATS issue...
how do I go about getting the system programmed out of the computer? I'm assuming the PCM (blue and green connectors) is what gets reprogrammed? Sorry, I'm new to fuel injection and vehicle computer systems (first project where I'm messing with any of this)
also, since it's needing reprogrammed is there anything else I should have changed in the system (Like removing rear o2 sensors since they're not being installed anyways)
thanks for the help so far and for the future assistance!
codes that read out were evaporative emissions purge valve (which was an issue since day one of having the van) i found when i was pulling the motor that the purge valve wasn't seated properly...
all the other monitoring systems were ok, including the fuel system monitor, so that leads me to believe that it is likely a VATS issue...
how do I go about getting the system programmed out of the computer? I'm assuming the PCM (blue and green connectors) is what gets reprogrammed? Sorry, I'm new to fuel injection and vehicle computer systems (first project where I'm messing with any of this)
also, since it's needing reprogrammed is there anything else I should have changed in the system (Like removing rear o2 sensors since they're not being installed anyways)
thanks for the help so far and for the future assistance!