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95 s10 blazer

this car will not start when its cold.i have been from one of the fuel system to the 4.3 efi motor in it. please help.

Did your inspection include fuel pressure testing? will it fire up when cold with a priming fluid? I am thinking the mixture is to lean for cold start,just how cold was it? cranking speed good? Is the pump original? filter? sock in tank ever been changed?

I have the same problem with my 93 s-blazer if you get and answer let me know and i will do the same

good crank speed ,20 degrees it also will spit and sputter when it is running it sunday i put a new fuel pump in it and strainer and spidervalve and fuel filter.

If just to eliminate it, I would have the battery load tested, many auto part stores will do it for free.

battery is good this thing is givein me fits about ready to stick a match to it

Check your coolant temp sensor.

Change the ignition coil and see what happens. If you have a distributor with the coil in the cap, it’s the first thing to guess at. Check that center electrode. If it has been ground to dust, there would be a weak spark.

thanks i thought it might be something like that never thought about the dis. cap i thought the coil might be goin bad if it has one

It sounds like the system is losing fuel pressure as it sits. It sounds like you replaced all of the components that normally cause this problem EXCEPT one.

Did you replace the pulsator check valve on the fuel pump assembly? This check valve keeps the system from draining back into the tank.

where is the pulsator check valve at?i have been from one end of this fuel sys. the other i have never seen anything that looks like a check valve

Here is a TSB that describes it…

File In Section: 6E Engine Fuel & Emission

Bulletin No.: 66-63-09

Date: April, 1997

Engine Hard Start or No Start (Replace Fuel Pump Pulsator)

1992-96 Chevrolet and GMC Trucks
1992-96 Oldsmobile Bravada
with Gasoline Engines


Some owners may report their engine is hard to start or will not start.


The fuel delivery system may have low or no pressure due to a ruptured fuel pump pulsator. The pulsator is the flexible connector between the fuel pump and the metal fuel line in the tank. This rupture appears as a tear in the pulsator openings and is the result of exposure to gasoline containing a high percentage of ethanol.


Follow the Strategy Based Diagnostic Steps for the reported symptoms. If diagnosis reveals low or no fuel system pressure, and the fuel pump is identified as a possible cause, follow the service procedure for, On-Vehicle Service, Fuel Pump, in the appropriate Truck Service Manual. Before replacing the fuel pump, inspect the pulsator for signs of tears or leaks. If the pulsator is damaged, replace it with P/N 25175836 and re-test the fuel system for normal pressure. This pulsator is made of Viton which is resistant to Ethanol content fuels. P/N 25175836 replaces P/N 25094266 for trucks. This change will appear in GMSPO parts catalogs as they are revised.

That was some good research by willey; but, it may not be pertinent to the 4.3L engine. I couldn’t find a listing at Auto Zone, nor at Advance Auto Parts, for a pulsator (damper); neither, could I find a listing for a fuel pressure regulator. Here’s a drawing of the Blazer 4.3L:

bigdaddyhedge, it’s up to you to use a repair manual to know the components of the fuel system (and, other systems), and how to do tests, such as fuel pressure testing, and finding parts in the system.

It is pertinent to this engine, it has the check valve. The check valve is a dealer only item, call a chevy parts department and you will find it.

Yes, willey, that is something for bigdaddyhedge1 to do (call the Chevrolet parts department). He has been informed of the TSB (again, good job!). I don’t need the instruction of the repair manual, the actual repairer does.
I don’t have control over the detail of the available drawings, at Auto Zone, et al. bigdaddyhedge (or, his repairer) should get those details elsewhere.

willey if this works and i think it will iou a sreak dinner. god bless ya ill let ya know the out come. i pick up the part in the morn.