Hard start and stalling issue
04-12-2021 | 08:04 AM
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Hard start and stalling issue
Hey my name is brad. I own a 96 z28 obd2 5.7l lt1.
Having an issue i can not seem to track down. I have a hard start issue. Ill give it 4 or 5 cranks it will start after about 10 mins it will drop all rpm and jump rpm back up if it does not stall and it will stall at any running time after it stalls and hard starts again it will run with no problem other than a misfire. The code its pushing out is a p0372 code i started having issues after i changed my water pump. I have changed the opti and the crank sensor but neither have fixed the issue. Im thinking its my ignition coil or ignition module. But i also hear it could be my fuel filter. Need help. Thanks.
Having an issue i can not seem to track down. I have a hard start issue. Ill give it 4 or 5 cranks it will start after about 10 mins it will drop all rpm and jump rpm back up if it does not stall and it will stall at any running time after it stalls and hard starts again it will run with no problem other than a misfire. The code its pushing out is a p0372 code i started having issues after i changed my water pump. I have changed the opti and the crank sensor but neither have fixed the issue. Im thinking its my ignition coil or ignition module. But i also hear it could be my fuel filter. Need help. Thanks.
04-12-2021 | 08:47 AM
#2
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From: Hell was full so they sent me to NJ
Re: Hard start and stalling issue
P0372 is for the high resolution pulse signal from the optical cam position sensor in the Opti. That can cause the problem you are having. You indicate you had this problem with the previous Opti, and replacing it with a new Opti did not fix the problem. What brand is the new Opti?
Since this problem occurred only after you replaced the water pump, you may have damaged the Opti wiring harness or the harness connector when you were working on the water pump. Did the new Opti come with a new “short” harness permanently attached, or did it just have a connector on the body of the Opti that you plugged the existing harness into? The will determine where the harness may have been damaged and what to look for.
You can also test the Opti harness using Shoebox’s instructions:
4th Gen LT1 F-body Tech Articles
Scroll down to the “Optispark Harness” topic.
The fuel supply may be a cause of extended cranking, and that problem can be diagnosed by checking the fuel pressure by using a pressure test gauge, turning the key to “RUN”, watching the pressure when the pump primes and shuts off. Should reach at least 40 PSI, and drop very slowly when the pump shuts off. Rapid pressure loss can indicate failure of the check valve in the pump, a leaking injector, a failing pressure regulator, or leaks in the lines.
But since this all started with the water pump replacement, check the Opti harness first.
The crank position sensor does not affect the way the engine starts and runs. It is only there for misfire detection.
Since this problem occurred only after you replaced the water pump, you may have damaged the Opti wiring harness or the harness connector when you were working on the water pump. Did the new Opti come with a new “short” harness permanently attached, or did it just have a connector on the body of the Opti that you plugged the existing harness into? The will determine where the harness may have been damaged and what to look for.
You can also test the Opti harness using Shoebox’s instructions:
4th Gen LT1 F-body Tech Articles
Scroll down to the “Optispark Harness” topic.
The fuel supply may be a cause of extended cranking, and that problem can be diagnosed by checking the fuel pressure by using a pressure test gauge, turning the key to “RUN”, watching the pressure when the pump primes and shuts off. Should reach at least 40 PSI, and drop very slowly when the pump shuts off. Rapid pressure loss can indicate failure of the check valve in the pump, a leaking injector, a failing pressure regulator, or leaks in the lines.
But since this all started with the water pump replacement, check the Opti harness first.
The crank position sensor does not affect the way the engine starts and runs. It is only there for misfire detection.
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