Dead Chevy

[B.G. Smith]

In reference to a 2001 chevy 1500 pickup with the 4.3 V6. Throttlebody injection. Vehicle has been sitting idle for a couple of years. Drained the fuel from tank, put in about 4 gallon of new fuel. Replaced the fuel filter. The in tank pump will pump but don't know the volume or pressure. Poured a little gas in TB and it runs for a short period (until fuel is gone) the it will continue to run a minute or so but sounds like it is only running on one cylinder. How hard is it to replace the TB injector? I am leaning toward the pump being the problem, any ideas or suggestions? Thanks. bg

 

[TFucili]

IIRC GM TBI only runs @12 psi. I'd start by checking pressure and flow. The injectors are not difficult to replace if it come to that. I had a CJ7 with a Howell TBI conversion and it was pretty easy to troubleshoot.

 

[Killer223]

might need the filter again, but yeah those tbi injectors are easy to replace and not to expensive either.

 

[brods]

Do you have a code reader or scanner? If its anything like the 88 or 89 TBIs you should be able to see the spray pattern from the injectors with the air cleaner off. Have someone crank the truck wile watching to see if the injectors are spraying (be safe about it of course). You can pull the injector connectors and use a test light to see if the injectors are getting power during cranking. On the 88 and 89 the ecm must receive an reference signal from the module in the distributor before firing the injectors. A bad coolant sensor will cause the ecm to think its -30 degrees and flood when starting in warm weather (found this one the hard way). A bad TPS may put the ecm in clear flood mode also causing hard starting. The last part of the FSM troubleshooting chart is to check the fuel pressure (9-13 psi). If you like I could take pictures of the troubleshooting charts for the 88 and email them to you. Don't know if the 2001 would be similar enough for them to be useful or not.

 

[Wayne M.]

Hold on! It's not TBI OR regular EFI! It's CPI! 4.3 vortecs are different. Check fuel pressure and the basics. After that get a book! See the diagram.

 

[TFucili]

Good catch Wayne!

 

[B.G. Smith]

Hold on! It's not TBI OR regular EFI! It's CPI! 4.3 vortecs are different. Check fuel pressure and the basics. After that get a book! See the diagram.

View attachment 99349

That's it. Thanks Wayne and all others who have replied. It looks like the injector is inside the intake manifold. It lists for around $150.00 bg

 

[Wayne M.]

Thanks. Ask how I know :-laf
We had a bunch of Jimmys in the fleet as supv rigs, and this system was troublesome. It's a central injector that branches off via plastic tubing to mechanical nozzles. Looks great on paper, and to me reminds me of a throwback to the old "Fuelie" mechanical setup. Some call that assembly a spider. Have fun with the line hookups at the rear!

 

[B.G. Smith]

That looks like a bad nightmare, just realized that the injectors are under the intake manifold. Best thing about it is this is not my truck. bg