96 Tahoe dies while driving and won't start

[east302]

Okay,

I noticed a few strange things: i tried to generate some trouble codes.

Unplug CKP: trouble code
Unplug MAF-Sensor: trouble code
Unplug CAM-Sensor: no trouble code
Unplug TPS: no trouble code
Unplug ECT: trouble code

When i took a look at the "live data" from my chevy, my diagnosis-software show me some strange values:

View attachment 182818
View attachment 182819

I don't believe, that this is normal when the car is not running.

Best regards with cold beer in my hands..

Matthias

When you plug your scanner in, it should be reading zero rpm and a TPS value of zero percent or close to it.

Try looking at that TPS again.

The ECT looks to be reading close to ambient, assuming it was around 24-degrees Celsius that day. But 160-C is really high, that's 320-F so that could be an issue there.

Your injection looks to be functioning correctly from the computer side. Each injector is getting voltage and the VCM is grounding each injector during cranking.

You have fuel pressure of 60-66 psi, correct?

You have spark at all eight cylinders, correct?

You have a passing compression test on all eight cylinders, correct?

 

[east302]

Grab a screen shot of those rpm, ECT and TPS values again. Maybe the ones you posted earlier were some type of stored history screenshots.

 

[Nightflyer]

The rpm, ect and tps are okay.

Now zero rpm, temperature it at 17 degrees and tps is at zero.

I've never done a compression test.
Fuel pressure is near 55psi (too low now...)?
I've spark on every cylinder.
I think that compression (bad or worn timing chain) has nothing to do with the injectors, right?

 

[east302]

Fuel pump spec is 60-66 psi and should hold for a few minutes with ignition off.

Compression test will tell you if you have issues with rings or valves.

You have spark, so it's either fuel or air.

Compression check:



Fuel pressure check:

 

[Nightflyer]

I've double-checked the fuel pressure...

After turning the ignition on the fuel pressure is at 50psi......i think that's too low..

 

[east302]

Cycle it a few times see if it comes up. Since you replaced injectors, it may take a few seconds to pressurize.

But 50-psi is on the low side. I thought you had 60 earlier?

 

[Nightflyer]

Hi east302,

You're right: there was pressure about 60psi.

I've tested it with another fuel pressure gauge from a friend (he has an professional one and i cant find mine)...his fuel pressure gauges reads 50psi at ignition on and engine off. While cranking it goes up to 52psi...

 

[east302]

Spray some starting fluid or carburetor cleaner into the throttle (open the throttle plate first), replace the air intake with the MAF sensor plugged in and try to crank it.

If it starts and then either dies or continues to run, it's probably your fuel pump.

 

[Nightflyer]

Ok,

I've installed an other fuel pump...59psi at the schrader valve

Aaaand: no fuel at the injectors and no start..

The chevy wants to start with starting fluid. The first time i used too much starting fluid, so it backfires one time thru the intake..

 

[east302]

Something's missing here, then.

What is the pressure while cranking?

What brand distributor cap and rotor did you use? Delco seems to work better than some cheaper brands. May not be good enough spark...kind of grasping at straws here.

What percentage is the TPS reading with throttle closed?

Just for the hell of it because I heard it somewhere, unplug the MAF and adjacent air temperature sensor and try to start it.