Wiring for 1999 tahoe injector

[Terry Deason]

I have a 1999 Tahoe 5.7 4x4 with a no-start condition. It has had the distributor cap and rotor replaced. Now the injectors are not firing. Need a wiring diagram to this section. If you have a good link or know where to get this I would appreciate it very much.

 

[exp500]

First determine if you have spark signal to coil, RPM signal to tach. Do you have theft lite flashing? Check engine grounds. Use OBD to test rpm cranking. Narrow search parameters some. I'll find some likely links.

 

[exp500]

Here is one to start with-

How To Test The GM Ignition Control Module (1995-2005)

GM 4.3L, 5.0L, 5.7L Index of Articles

easyautodiagnostics.com

 

[Terry Deason]

First determine if you have spark signal to coil, RPM signal to tach. Do you have theft lite flashing? Check engine grounds. Use OBD to test rpm cranking. Narrow search parameters some. I'll find some likely links.

Yes, I have spark at all 8. Have fuel pressure at 62psi. How to test rpm cranking. Will run for a few sec. with gas in the throttle body.

 

[exp500]

Your scanner should be able to read rpm. Trying to verify computer signals. All info helps on this.
Check engine ground wires to firewall and negative batt cable. Do you have theft lite flashing/on ?

 

[exp500]

Terry- I reread your original post back from april. Many tests Suggested to you, but vague responses as if you have tested nothing and are going by your feelings of it has fuel,62lbs, has spark and now injectors arent firing.
Tell me, how did you verify spark on all 8 and Injectors not firing?
If you physically verified, then check VATS as requested. Many things and interconnections in these systems and this truck is easy compared to many others.

 

[Terry Deason]

firing on all eight and 62 psi. No codes and no theft light on. Verified by spark tester and fuel pressure gauge. The confusion was when I had a bad fuel tester gauge. Rented it at Autozone and had to get another that works. And this is how it stands now.

 

[OR VietVet]

I would get back in that distributer and inspect the module and the pickup coil. Common failure has been a broken wire at the pickup coil that leads to the module. If wire is broken, you can install a new/reman distributer or disassemble the distributer and replace the pickup coil and while in there do a new module too. You may have a bad module too. I have never seen a failed pickup coil with wires intact. It can happen but I have never seen it.

 

[Terry Deason]

I have spark at all eight that was confirmed with a spark tester.

 

[OR VietVet]

Did you inspect inside the distributer for any problems? Do the tests you feel comfortable with then.