1996 chevy s10 4.3L v6 loss power high rev

foremanrider450 · 05-07-2009, 06:45 PM

this truck idles fine but around 2400rmp it loses all power. if you can help thanks

hrlow2 · 05-07-2009, 06:53 PM

Sounds like a blown head gasket.Saw many like that. If blown between cylinders, will not get water in the oil, but your compression is traveling to the adjoining cylinder.

**mack1** · 05-07-2009, 10:31 PM

Hi foremanrider450 and welcome to TSF,

I suspect gas starvation at the higher rpms. Last time I had that problem, it was a fuel filter that was almost totally stopped up (by water). Would let enough volume pass for low speeds, but not enough for the higher speeds.

That engine used a single fuel line with electric pump external from the tank.
Not sure the filter on the circulating type systems will hold back water, but might be stopped up by debris.

There is a test for volume flow where you disconnect the line and see how much the pump will deliver at the engine in a given time. Sorry I don't remember the volume or time, but maybe someone will jump in and tell us both.

Another way to test would be to use a pressure gauge on the fuel line at the engine. The pressure (probably about 60 psi for your engine) should hold to near pressure at all rpms. A drop of 9 psi at high rpm is acceptable for normal operation.

Very best regards,
Mack1

edited: I forgot about the fuel pressure gauge method.

foremanrider450 · 05-08-2009, 06:07 AM

ok well i will try that out and i will let you guys know what happens thanks

**mack1** · 05-08-2009, 06:16 AM

If you don't have a pressure guage, you might be able to use one for free at a local Auto Zone. Other parts houses might also do the same.

Best regards,
Mack1

**Raylo** · 05-08-2009, 10:26 AM

If you decide to test fuel pressure make sure you look up the actual spec for fuel pressure for the type of injection you have. Those motors came in 2 versions..... CPI and TBI and the pressures are very different. CPI spec is about 60 psi and starting and performance is very sensitive to pressure. TBI runs a lot lower pressure and I believe is not as sensitive to fluctuations as CPI, especially for starting. Don't forget to consider fuel filter, too, as mentioned above.

05-07-2009, 06:45 PM	#1 (permalink)
foremanrider450 Registered User Join Date: May 2009 Posts: 2 OS: xp	1996 chevy s10 4.3L v6 loss power high rev this truck idles fine but around 2400rmp it loses all power. if you can help thanks

05-07-2009, 06:53 PM	#2 (permalink)
hrlow2 Registered User Join Date: Oct 2008 Location: West Virginia Posts: 458 OS: Windows XP Home SP2	Re: 1996 chevy s10 4.3L v6 loss power high rev Sounds like a blown head gasket.Saw many like that. If blown between cylinders, will not get water in the oil, but your compression is traveling to the adjoining cylinder.

05-07-2009, 10:31 PM	#3 (permalink)
mack1 TSF Articles Team Join Date: Nov 2007 Location: Texarkana, Texas Posts: 1,245 OS: xp sp3 My System	Re: 1996 chevy s10 4.3L v6 loss power high rev Hi foremanrider450 and welcome to TSF, I suspect gas starvation at the higher rpms. Last time I had that problem, it was a fuel filter that was almost totally stopped up (by water). Would let enough volume pass for low speeds, but not enough for the higher speeds. That engine used a single fuel line with electric pump external from the tank. Not sure the filter on the circulating type systems will hold back water, but might be stopped up by debris. There is a test for volume flow where you disconnect the line and see how much the pump will deliver at the engine in a given time. Sorry I don't remember the volume or time, but maybe someone will jump in and tell us both. Another way to test would be to use a pressure gauge on the fuel line at the engine. The pressure (probably about 60 psi for your engine) should hold to near pressure at all rpms. A drop of 9 psi at high rpm is acceptable for normal operation. Very best regards, Mack1 edited: I forgot about the fuel pressure gauge method. __________________ "If you like yourself others will like you also" me "Don't drink downstream from the herd" Will Rogers Submit New Articles Here Last edited by mack1; 05-07-2009 at 10:38 PM.

05-08-2009, 06:07 AM	#4 (permalink)
foremanrider450 Registered User Join Date: May 2009 Posts: 2 OS: xp	Re: 1996 chevy s10 4.3L v6 loss power high rev ok well i will try that out and i will let you guys know what happens thanks

05-08-2009, 06:16 AM	#5 (permalink)
mack1 TSF Articles Team Join Date: Nov 2007 Location: Texarkana, Texas Posts: 1,245 OS: xp sp3 My System	Re: 1996 chevy s10 4.3L v6 loss power high rev If you don't have a pressure guage, you might be able to use one for free at a local Auto Zone. Other parts houses might also do the same. Best regards, Mack1 __________________ "If you like yourself others will like you also" me "Don't drink downstream from the herd" Will Rogers Submit New Articles Here

05-08-2009, 10:26 AM	#6 (permalink)
Raylo TSF Enthusiast Join Date: Feb 2006 Location: Maryland, USA Posts: 524 OS: XP Desktop, Vista HP Notebook, XP Notebook	Re: 1996 chevy s10 4.3L v6 loss power high rev If you decide to test fuel pressure make sure you look up the actual spec for fuel pressure for the type of injection you have. Those motors came in 2 versions..... CPI and TBI and the pressures are very different. CPI spec is about 60 psi and starting and performance is very sensitive to pressure. TBI runs a lot lower pressure and I believe is not as sensitive to fluctuations as CPI, especially for starting. Don't forget to consider fuel filter, too, as mentioned above.