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Hoping it's not the fuel injectors on my S10

'96 Chevy S10 pickup, V6, 2WD



I was dumb and didn’t give the truck a tune up after I purchased it, and I naively drove it until recently. Thanks to my ignorant vehicular ways, I now can’t get the engine to start.



In order, I’ve replaced the battery, spark plugs/spark plug wires, fuel filter, and fuel pump relay. I’m now getting voltage to the spark plugs, and I’ve deduced the issue to the fuel system. I didn’t think that I was getting pressure in the fuel line when I replaced the fuel filter, but I found a nozzle to place a pressure gauge on the fuel line on top of the engine - gas squirts out when I press on the nozzle, so I’m assuming that the line has pressure and that the injectors are getting what they need. I’m going to the parts store to get a pressure gauge to make sure that they’re getting enough pressure…



After the replacements, the engine starts up for a bit when I spray some carb cleaner in the intake, so I know it’ll run.



What are the chances that it’s the fuel injectors and not the pump, and what’s the best way about replacing them after going further into debt?



This has been my own personal suckfest - I’ve got to walk a mile to and from the parts store, and I’m trying to get as much out of each trip as I can…any help/advice would be greatly appreciated! :slight_smile:

Dont think it is the injectors,how many miles?-Kevin

almost 190,000

You really don’t want to do that pump do you?

Chance of injectors over pump,slim but get a pressure gague on it.

The pump your truck uses has a much higher replacement rate than the injectors (espicaly all 4)

More then likely the pump-Kevin

Take a test light and verify that the fuel injectors are receiving battery voltage. While I’m not familiar with this circuit off the top of my head, the injectors should be fused and the grounds that operate the injectors are provided through the ECM.

The injector pulse can also be checked with a Noid light or by listening for a click sound from the injectors as the engine is cranked over. A mechanics stethoscope or long handled screwdriver can be used as a listening device by placing the tip against an injector.

I am pretty darned sure that the truck has a central throttle=body not 4 injectors. However it could still be the problem.

If I had my choice, it would’ve been running by now :wink:

But seriously, I’d rather replace the pump than the injectors.

I would bet the pump too. Injectors are good for many hundreds of thousands of miles and you wouldn’t have all of them at one time. When you turn the key on you should hear the pump run for a couple seconds. If not try banging on the tank and see if that gets it going. Just because gas squirts out of the shrader valve doesn’t mean there is enough pressure to run the system. If you do need injectors, nothing wrong with the junk yard.

Fig. 7 shows six fuel injectors: http://www.autozone.com/autozone/repairinfo/repairguide/repairGuideContent.jsp?chapterTitle=Wiring+Diagrams&partName=Chassis+Electrical&pageId=0900c1528025048b&partId=0900c1528025037b You can put a finger tip on the top of the fuel injector, while the engine is cranking, and feel each time the fuel injector clicks (sprays)-----about, once every 2 or 3 seconds.
When you go to the parts store for that fuel pressure tester, make sure to get an adapter which will fit your Chevy fuel system. AND, get the repair manual. You need it. It will save you $$.

I did not catch that the OP stated V6,in that case for 96 this would be CPI with the spyder and 6 poppet valves. If it was the 4 it would be using 4 individual injectors.Or more correctly CMPI,this uses one injector and 6 poppet valves,IIRC

Wiring diagram shows all 6 injectors are powered by the same fuse. The diagram also shows the crank sensor and ign. module are also routed through this fuse.
You might take a look at Fuse No. 10, 20 amp.

So its not CMPI? I went off a 95 FSM. I checked in the ARRC data base and the 96 4.3 is shown to be using CMPI RPO L35 but you can see wiring to each injector as if it were multi port? this is odd.

Is that a good idea?.Isnt there enough pressure at the tips to inject gas in your skin?-Kevin

I came across this description of the 96 L35 V6 a ways back. The entire document is attached. Here’s an excerpt describing the fuel injection system (1 central injector with 6 poppet valves):

The redesigned Vortec 4300 V6 relies on solid, proven technology to achieve its outstanding level of performance:

Sequential Fuel Injection (SFI) provides the benefits of precise fuel delivery to each cylinder without the cost and complexity of conventional Multi-Port Fuel Injection. The centerpiece of the GM-patented SFI system is a single disk injector that is connected to six individual poppet valves with flexible lines. The central injector controls the flow of pressurized fuel to the poppet valve nozzle in each intake runner.

The sophisticated yet simple SFI system delivers significant benefits to Chevrolet customers:

Fuel delivery is precisely controlled for optimal cylinder-to-cylinder distribution, producing a smooth idle and increased horsepower and torque.
The reduced thermal mass of the poppet valve (compared to conventional solenoid injectors) provides near-instantaneous hot-starts

The poppet nozzles’ design and optimum location produce an effective spray pattern that contributes to the engine’s smooth idle and outstanding fuel efficiency
The SFI’s modular design simplifies service; its central injector can be replaced as a single unit.

Ed B.

When I said it was probably a central throttle-body I was going by my '99. It was!

Vortec 4300 V6 Engine (L35)
After 18 years of continuous development, the Vortec V6 has earned a reputation as a powerful, dependable and economical truck engine. Born in the energy crisis of the Seventies, the 90-degree V6 has matured in the Nineties to become a sophisticated and successful member of GM’s family of engines.
The '96 Vortec 4300 V6 is the culmination of this evolutionary process. It provides many of the performance characteristics of a V8 engine while maintaining excellent fuel economy.

This version of the Vortec V6 debuted in 1992 as an optional engine in several Chevy truck models. This versatile V6 is distinguished by a host of technical advances, including the industry’s first Central-Port Fuel Injection, a steel hydraulic roller lifter camshaft, high-swirl/fast-burn cylinder heads and a tuned two-piece intake manifold. Many of the design technologies introduced on the Vortec V6 have been transferred to the new Vortec V8 engines for 1996.

Dosen’t this say it is Central Port??
And to all you V6 “Knockers” this sounds like a pretty good engine, to me.

Adhdork, what are the numbers and letters on top of the engine?

msn.autos shows that the 1996 Chevy S10 P/U had the 2.2L and the 4.3L with SEFI fuel system. SEFI = Sequenial Electronic Fuel Injection, right?

Are we trying to place a 3.8 in a 96 S-10? All I ever saw was the 4cyl(2.2L I believe) and the 4.3.

Wikipedia shows that this 4.3 could be TBI (suprise). It also shows it could be SEFI (hence the 6 injectors with wiring). It also shows that the last CPI year is 1995 but my ARRC data base shows it as CPI. I bet this gives parts people headaches.

It shows TBI VIN code Z until 1996
It shows CPI VIN code W until 1995
But It also shows VIN code W (cpi)in 1996, with SEFI VIN code X only from 2003,till 2004. It appears to me it was either TBI or CPI in 1996 and SEFI only in 2003 and 2004 with VIN code X.

Well, I know my '99 had central port injection. It was a 4.3 Auto 4X4