Bill
I used the meter on the switch.. With the key out- key in- switch off-switch on-in the on position-run position-start position- and again after the Eng. died.
All is good in the switch and the wires coming out from the switch.. Used also an idiot light along the wires to check for a breaks (all Good)..
Saturday I will check the fuel pump also in these same on--off--start--run positions.
I replaced all the Eng. sensors, However,,over the years I have gotten bad parts right out of the box. I'm looking at two areas ---oil pressure sensor and
the crank sensor (both are New).
The PCM is also new, and programmed at one of the local dealers,, along with an update for the fuel system (recommended by GM) .
I have also added a list in the attachments of all the parts I have replaced in the pasted couple months... I under stand that the PCM runs the fuel pump for the
first 4 seconds (Ing. switch start/ crank position) and then the Oil pressure sensor on the back of the Eng. takes over ounce it reaches 4 lbs or > of oil pressure.
I get 24 lbs. oil pressure instantly.
What is the best way to check the oil pressure sensor switch with-out removing it. To remove the switch you have to remove the Intake Manifold.
By now you must cringe when you see my name... LOL
Thanks Bill
mike

 

Bill
I used the meter on the switch.. With the key out- key in- switch off-switch on-in the on position-run position-start position- and again after the Eng. died.
All is good in the switch and the wires coming out from the switch.. Used also an idiot light along the wires to check for a breaks (all Good)..
Saturday I will check the fuel pump also in these same on--off--start--run positions.
I replaced all the Eng. sensors, However,,over the years I have gotten bad parts right out of the box. I'm looking at two areas ---oil pressure sensor and
the crank sensor (both are New).
The PCM is also new, and programmed at one of the local dealers,, along with an update for the fuel system (recommended by GM) .
I have also added a list in the attachments of all the parts I have replaced in the pasted couple months... I under stand that the PCM runs the fuel pump for the
first 4 seconds (Ing. switch start/ crank position) and then the Oil pressure sensor on the back of the Eng. takes over ounce it reaches 4 lbs or > of oil pressure.
I get 24 lbs. oil pressure instantly.
What is the best way to check the oil pressure sensor switch with-out removing it. To remove the switch you have to remove the Intake Manifold.
By now you must cringe when you see my name... LOL
Thanks Bill
mike

 

Mike

The Oil Pressure Switch will NOT cause the engine to shut down. So,, cross that one off the list.

Im leaning towards the fuel system.

 

Bill...how do I bypass the computer and jumper the fuel pump directly? Please be specific as I am an electrical moron.

 

For Bill and Mike....I may have had a breakthrough...we had put in a complete c6 zo6 exhaust system last year, including the zo6 manifolds and cats..which are very tight on the passengers side. I tied back the wires under there with a large zip tie..which I found had been melted thru by the manifold. I reached my hand under there and fiddled with the loose wires and the car started right up...so it could be one of them is shorting out..I am thinking one of the grounds or the crank sensor wire...but I will have to take off the manifold to see what is going on under there.

 

So I just ran it for 15 minutes and drove up and down the block several times when it started to stall again...just made it back into the driveway and it won't restart...either the heat is getting to one of those wires or the fuel pump is pooping out when overheating. I just don't think its anything with the BCM or the PCM...but it still could be one of the relays on the passengers side footwell

 

Until you can confirm the integrity of the wires on the passengers side, near the starter, don't do any other troubleshooting. Once you examine those wires and fix if necessary, then resume troubleshooting. Take pictures if you find damage.

BC

 

Thank you Bill! This exact problem happened after sitting for the winter and recharging the battery. I'll research your recommendations.

John

 

Not sure on these Corvettes, but older GM EFI systems used an oil pressure switch in parallel with the fuel pump relay. If the relay puked and you still had oil pressure, you could still drive the car. Low oil pressure or a bad oil pressure switch would not shut it down.

I would be sticking a fuel pressure gauge on there with a long enough hose so you can duct tape the gauge to the windshield and watch it going down the road. Not pretty, but this works.

 

Hi Bill....I have been working on the corvette...I did get to the suspect wires but they seem to be OK....I did find that the o2 sensor harness was too close to the exhaust and had melted some of the sheilding on it, but the wires themselves seem unharmed. I cleaned the grounds under the battery tray and retightened the battery terminals,. The car did start right away, but again stalled after a few runs around the block. Then it won't restart again.
I also noticed that my tailights are not working and the flashers are only flashing on the front lights...not the rear. I am at my wits end...I feel it might be the fuel pump or the anti theft relay...how do I get power directly to the fuel pump to test it?
echelonphoto is online now Report Post Edit/Delete Message

 

Bill,
I have a 2000 c5 convertible with 60k miles, when the car is sitting idling or I'm driving around I am hearing a whine/humming/buzzing sound from the rear speaker of course the radio is off but it sounds like the radio is on with the volume turned off. This annoying sound that I am hearing also fluctuates when I turn on the blinkers or rev the engine/rpm range. I hear it all in the rear driver side speaker, well I'm pretty sure that is where its coming from. Also if I have my interior lights on and I look closely they dim up and down with fluctuating sound/blinkers/rpm rev. Is this some type of electrical feedback my Vette is experienceing?? It is not very loud but enough to be annoying! Please help!

 

Mike


GM C5 LS engine does not use a Oil Pressure kill switch. Dont know why but it doesnt.

echelonphoto
Tail lights/ blinkers are most likely a defective Multifunction switch. Until you monitor fuel pressure and jump out that relay, its tough to go any further.

devilredc5

You have a LOT going on here.

You have to start at the battery. Have it tested. Look at CCA and reserve capacity. If there questionable, replace the battery.

Read and post the following:

Alternator output engine running. Read it from the BATT terminal on the back of the alternator and at the battery.

Instrument Panel digital and Analog volt meter reading. Engine off key on and engine running.

Post IPC Gage readings and compare with the battery voltage reading.

Look in the Instrument Panel Fuse box. Fine the RDO/ CD Mini fuse #5 and pull it. See if the noise goes away.

Read the alternator OUTPUT and the battery while the engine is running. Measure it on the AC Scale and see if you get any AC readings. If you get any readings, you may have some bad diodes in the alternator.

ENGINE RUNNING. With the DC Volt meter on DC Volts, put the pos lead on the Alternator BATT output terminal and the Neg lead on the battery Positive terminal. Reduce the scale and see if you have any reading. You should NOT but if you do, the starter solenoid connection is loose/dirty bad..

Have you cleaned your chassis grounds?

Bill

 

Ok thanks bill I will check it out and get back to you

 

I recently also had a random stalling issue and No Codes thrown. Turned out to be a faulty Crank Position sensor. I'm not saying that's your problem but something to keep in mind. I'd start by checking the ground post at the rear of the car for the fuel pump.

When it stalls, cycle the ignition key to off and then try to restart the car and see if the fuel pump runs to pressurize the system at start up. If it does, the fuel pump is likely not your problem.

 

'....update on situation....yesterday the car ran briefly and then stalled again...wouldn't restart. This morning ..still wouldn't start. I jumpered the fusebox connectors for the fuel pump relay....I heard the fuel pump running when I turned the key on...after several crank attempts the car started...I let it idle...everything sounded great...smooth idle...I then activated the left blinker and the car immediately stalled...I turned off blinker and car restarted...tried blinker again and it worked normally...no stalling...restarted car several times normally...I drove it just in my court...as I was turning around , car started to stumble..I parked it...won't restart and I don't hear fuel pump now....I pulled two history codes....BCM 2578 and 2583...which has to do with a short in blinker circuit...does this sound like a grounding issue? Is there any way to take the blinkers out of the circuit and see if that is shorting electrical system?

 

Pulled another history code....IPC 1542H...which is oil temp switch to ground...car is still idling...I am afraid as soon as I move it it will stall....do you think a wire is intermittently shorting out?

 

Man,,,,,,,,,,, You have tooooo many weird things happening. Examine the wiring under the battery and at the PCM below the battery and look for battery acid damage.

 

Well when even you are stumped...I know I have a problem...so you don't think its a ground issue? As I noted before....the shielding on my o2 bundle was melted, but the the wire insulation looks intact..so I don't think its that.

 

Just started successfully again...hit the hazard switch and it faltered and died...turned off switch...restarted fine...put on blinker...died...Blinker does not work now with key in on position

 

I'm not stumped... I'm not seeing all the symptoms. There are more but you are not seeing them. Its difficult for me to explain to you what I see, feel,hear and look for when I troubleshoot a C5.

If it dies, you are loosing SPARK, FUEL COMPRESSION or AIR. Thats what it takes for the engine to run. When it wont start, do you have fuel pressure and spark??