1996 Tahoe no start

[rwbruce]

Here we go. This has got me stumped. The tahoe sat for about a month and the battery ran down completely (glove box light was on). Charged the battery up and then no start. It was running perfectly before. Replaced the crank sensor, coil, and coil module. I have spark at the plugs and 60 PSI at the schrader valve. I can pour gas down the carb throat and it will run then die when out of gas. Checked all the fuses about a dozen times. Not getting any error codes. Got me stumped. What would be stopping the injectors from squirting?

Thanks
Randy

 

[exp500]

IS Anti-theft light flashing/solid? Does it light when key to on not start?
Book fuel pressure 62-68. Most will run at 60 but not below.

 

[Joseph Garcia]

Welcome to the Forum from NH.

Lots of knowledgeable folks here who freely share their knowledge, experiences, and perspectives. Knowledge is power.

I hope that you will become a participating member in the Forum's discussions.

Pics of the truck, please.

I cannot personally help you with your question; however, other members on this Forum that are much more knowledgeable than me will chime in.

 

[OR VietVet]

Welcome to the forum. Leaning toward what @exp500 said or a problem with the spiders at the throttle body. Not a carb.

More Information for ACDELCO 2173245

 

[rwbruce]

IS Anti-theft light flashing/solid? Does it light when key to on not start?
Book fuel pressure 62-68. Most will run at 60 but not below.

No security/anti-theft light flashing on the dash board. Do you think that 60 psi is too low for it to start?

 

[rwbruce]

IS Anti-theft light flashing/solid? Does it light when key to on not start?
Book fuel pressure 62-68. Most will run at 60 but not below.

Also, the security light does not come on with the key is turned. Isnt it supposed to come on and then off?

 

[exp500]

That is a big clue, maybe bulb removed? I would try that first. That is how anti-theft reacts.

 

[rwbruce]

Ok here is the latest. Pulled the dash and the inst panel. just to see why the security light was not coming on and there is no bulb in that spot. Never has been. the contacts are fresh and clean. But just to see i switch a bulb plugged it back in and nothing bulb does not light. So i think i am not going down the correct path but wondering if i should do the relearn process anyways?
Or focus back on the injectors see if they are getting power?

 

[exp500]

Shoulda tested for power and ground at bulb socket. Bulb is currently installed I hope.
Next test is to look at wiring diagram .You have to figure out the how on the ground side. Since bat went dead, It forgot it was in drive mode. Now it is searching for something it can't find, so no start is the likely problem. I would at least check all fuses while installed again -with a meter, key on also.
Factory radio still installed? Do you have 2 chipped keys?
Do you have access to a tech2 or similar scanner?

 

[rwbruce]

So i can still test the socket dash is still apart. The bulb i put in there did not light when i cycled the key several times and tried to start it. Checked the fuses again with a meter all good. Radio is not the original but i removed it just in case. I did notice the the radio fuse was blown when i originally tested the fuses from the first no-start condition. No chip in keys which makes it a passlock system? Its a 1996. I have a snap-on Solus scanner and no error codes to speak of.
Any help will be appreciated i love this Tahoe, perfect condition and this has me stumped.

Thank you

 

[exp500]

Simple enough to test for power at injectors, unplug big cable on intake. test connector for power and ground, then test injectors for same while cranking.
The 96 is unique in several areas, so I recommend you get factory service manual. Try ebay.
I'm pretty sure passlock is factory on yours (chip key). Could remove lower column cover and look for ring around lock cylinder.
Remember that computer runs at 5 volts so don't put 12 at the wrong place.
Here is another thread with some diagrams while you wait for your manual for troubleshooting guide on no start.
HELP! NO INJECTOR PULSE,...non running 96 suburban tried everything | Page 3 | Chevy Tahoe Forum | GMC Yukon Forum | Tahoe Z71 | Cadillac Escalade - Tahoe Yukon Forum
Will your snapon read all the modules/two way comms?

 

[Eman85]

You should have passlock and a security light. If I remember correctly to reset passlock turn the key to the on position for 10 mins. Then turn it off and try to start. Do some google on security ;ight reset.

 

[east302]

This is on a 96, right? GM brought Passlock out in 95 or so but wasn’t added to the GMT400 line until 98.

After pressurized and with ignition off, does the pressure hold steady for a few minutes (say, above 50 or so) or does it drop to zero?

Have you tried a different pressure gauge?

Sorry, but since life happens and the gauges on these get flaky, are you sure you have gas in it?

If it runs and dies on starter fluid, that’s usually going to point to a pump but your pressure looks reasonable (unless the gauge is really inaccurate).

Here’s the diagram for the injector harness on a 98. There may be a difference between a 96, but it’s probably similar. Ignition on, you should see battery voltage on the connector side pink wires to a ground. The VCM controls the ground to pulse the injectors, so a noid light would be needed for testing that.

 

[rwbruce]

This is on a 96, right? GM brought Passlock out in 95 or so but wasn’t added to the GMT400 line until 98.

After pressurized and with ignition off, does the pressure hold steady for a few minutes (say, above 50 or so) or does it drop to zero?

Have you tried a different pressure gauge?

Sorry, but since life happens and the gauges on these get flaky, are you sure you have gas in it?

If it runs and dies on starter fluid, that’s usually going to point to a pump but your pressure looks reasonable (unless the gauge is really inaccurate).

Here’s the diagram for the injector harness on a 98. There may be a difference between a 96, but it’s probably similar. Ignition on, you should see battery voltage on the connector side pink wires to a ground. The VCM controls the ground to pulse the injectors, so a noid light would be needed for testing that.

View attachment 354700

This is 1996 manufactured in 95 no key chip. The pressure gauge will read 60-62 while the engine is turning over and then drop to 60 and hold. I have a half tank of gas but I will be changing the fuel filter today. I do not think that this is the issue but I can cross that off the list. I do not have a different gauge to try but this one is new. Thanks for the diagram!!! trying stuff today...crossing my fingers.

 

[rwbruce]

Changed the fuel filter tried to start nothing. Pressure at gauge is 62 when turning motor over. Pulled wires out of the injector loom and when the key is on pink wire has power. What is a noid light? I am going to go thru the relearn procedure to see if that works. If it doesn't I am not sure what to try next.

 

[exp500]

Thanks for the update. Best of luck.

 

[exp500]

Noid light is injector signal tester nickname. You can use a 194 bulb and fold pins straight to plug +-.
On the relearn, I believe you have to at least touch starter on the end key on sequence.

 

[th3 shifty]

having the same issue... same year truck.. will crank and not kick over.. sometime it will let a slight stumble but wont kick.

 

[exp500]

@th3 shifty - Please start your own thread so any long troubleshooting stays seperate and in one place. Thanks.