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Would you explain again what you mean by "if I take it out again it will die with in 10 to 15 minutes". While you are at speed on the road? When stopping for a light? While idleing? When you put the pedal down after stopping? When you put it in gear? Or not starting after running?
 

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If you don't have access to real-time diagnostics, or codes, then the rest of us are limited to guesses.
If you could at least narrow down when / how it tends to die on you, at least our guesses will improve.
 
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Discussion Starter #23
If you don't have access to real-time diagnostics, or codes, then the rest of us are limited to guesses.
If you could at least narrow down when / how it tends to die on you, at least our guesses will improve.
Ok so I can drive to work no problem maybe about 7 minutes away mostly all freeway and I can make it back home same time and distance but ill get home park it and maybe let it sit for an hour and I'll go and start the car and it will som times die while in park...and if it doesn't die in park I will while driving down the street while in gear and the code it kicks up is a p1371
 

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Okay, so google "DTC P1731". The top links will tell you the code's meaning and the various causes.
 

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Interesting. This is the one where a fuel pump, then a new opti, and then a new battery. And it's not run right after that. For the OP you'll be way ahead of the curve if you can work through the routines in the link above to find what part of the opti is out of wack. Most problems with AM optis is a mix of poor quality parts, poor assembly and manufacturer, and careless inexperienced installation. You'll be at the mercy of some sort of shop to hopefully know how to remove, blueprint and re-install that opti. IDR whther you got your oem opti back, but the sensor in most all aftermarket units have been suspect to sketchy function when up to operating temp. If you have your original opti, then you're a lucky man and more probable getting a good operating unit by combining the two together.

If you're using a shop, then good luck. If you're contemplating even a little about doing the R&R yourself, then post some of the things you've pulled up searching on your own, and you might get additional guidance on here.
 

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Ok so I can drive to work no problem maybe about 7 minutes away mostly all freeway and I can make it back home same time and distance but ill get home park it and maybe let it sit for an hour and I'll go and start the car and it will som times die while in park...and if it doesn't die in park I will while driving down the street while in gear and the code it kicks up is a p1371
That code is opti-related.
 

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OP now has two "diagnostics" pointing to OPTI., the second after a OPTI "Parts Swap". The second OPTI could be bad OR there may be a wiring harness issue.

Sometimes when the "parts cannon" is fired and the new part does not clear a very generic code, actual trouble shooting may be cheaper than repeated guesses and multiple "parts cannon" firings.

As the OP's issue is still present after a repair shop has charged for repairs the OP could reach out to the shop and see if they will back their diagnosis, and replace the OPTI again, OR maybe check the wiring or refund some labor.If the shop does not stand behind the work the OP could also have the code documented by a third party and see if the better business bureau or a professional association might help.

The bottom line is the low and high resolution signals may be found at the OPTI but not at the PCM pins. A guy who is good can make these tests with a oscilloscope by carefully back probing the connectors (not piercing the wires). This may be cheaper than repeated OPTI swaps. There is a sub harness between the OPTI and the main harness, it might be worth the cost to just replace it.

OP if you do go to another shop be sure to ask if they have a scan tool that displays live data and has someone who has and can use a scan tool with oscilloscope features. You are lucky in one way with a OBDII 96. The crank sensor makes looking at the OPTI signal much easier. The oscilloscope will show things the multimeter can not.. Signal dropouts(missing pulses) and low signal voltage(PCM needs good levels to process the signals).

If you or a friend can use a multimeter the link I posted is a good starting point.
 

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+1 on given the amount of parts already replaced..this "could" be a intermittent wire issue anywhere that when car gets to operating temp it dies.

FWIW I chased wtf does the car randomly die....started gently tugging on wires while engine was running. My needle in the haystack was the brown wire in the 4 pin top opti harness just came out of the connector. It was never crimped when made. The car immediately died when I just touched that wire

...so start wiggling some wires...the grounds on DS head at coil would be a good start
 

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Another great advice from BALLSS. If you find out that was the wiring problem, by all means get your old OPTI and keep t in the trunk. Aftermarket optis are often POS.
 
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G104 on the ICM side of the head will mess up the PCM and or the ICM if it can not handle all the current that several things that ground at that point use.
Post #20 seems like a good idea.

As many others have suggested wiggling wires is a good start as it requires no tools.

Ground testing can mean more than wire wiggling and cleaning connectors. Voltage drop through the wire is the last and only prof of hidden ground problem.

Signal measurements are hard for most DIY but the best way to avoid OPTI swaps. A error code is not a good reason to start replacing parts.

As many people have said wiring may be a hidden hard to diagnose issue which gets worse with car age.
 

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Discussion Starter #34
It was holding at 45 and started dropping very slowly after 1 minute then I turned ignition off and released pressure and went to put the car in the on position and it stays on 41 to 42 psi ?
 

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You should measure fuel pressure:
1. Ignition on, engine not running.
2. Idle
3. Idle, vacuum line pulled off the FPR.

Your numbers seem to be fine, but make three above mentioned measurements.
 

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If you have an extra $20, it's far worth it to invest in an OBD bluetooth reader on amazon. Download Torque Lite and you'll be able to monitor a lot of data through your phone.

I was having a stumble, hesitation and stall issue only while driving. No codes would pop. When idling and in park, I saw nothing out of the ordinary on the app until I reved it up. It was then I noticed my temp would drop down to -44*F.

I took the pigtail off the temp sensor and saw the terminals on both the sensor and pigtail was completely rusted and falling apart.
 

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I had a random ignition issue where the car would cough and die. Just flat out run perfectly and then nada. Started out of nowhere. Spent HOURS tracing every single wire underhood and making sure everything was 5x5. No codes. Completely random.

I finally found the issue by popping open the underhood fuse box and wiggling ****. One of the fuses was making good contact when cold, but as it warmed up - the clearance increased between the spade and the female receiver - making a short. Pulled the box, fixed the connection, problem solved.
 
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1. Go to a very very different shop.
2. Don't use car parts stores for diagnostic work.
3. Search on here and/or google the large amount of information on exactly your "runs and then doesn't" condition. Hint: look into issues that come about as the car comes up to temp: resistance issues, grounds, ignition coil and ignition coil module, there's more
We had a problem with our 96 Chevy SS shutting down out no where. We took it to this automotive electrical shop. It turned out to be the fuse block that's under the hood. He cleaned and soldered all the connections. That was over 16 years ago. We have not had that problem since.
 

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Discussion Starter #40
Ok so I measured my key pellet resistance and bout a gm #12 vats key got it cut today and started my car but....my passkey fault light is still on ???
 
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