# 96 s10 blazer wont start



## mrc9999 (Sep 18, 2012)

ok any help on this would be welcome!!! I have a 1996 Chevy s10 Blazer 4.3L vortek, 4x4, 4 door and the stupid thing won't start. following is a list of brand new parts I have replaced after I will explain what its doing. NEW: plugs and wires, battery, distributor cap, rotor button, camshaft sensor, crankshaft sensor, ICM, Ignition coil, Fuel Filter, Fuel tank vent valve, Fuel Pump, Fuel relay in the glove box, and all in the dash fuses are good.

Truck will not start. Turns over stong, good spark, plugs are not wet. There is no smell of gas at all coming from the engine compartment. Throttle body is completely dry. Checked the fuel pressure, by all means its supposed be 57-61psi, its not however. I have read thousands of posts and threads trying to make head way on this darn thing and all I've been doing is throwing parts at it not fixing it. I know that if it not pushing the gas at the right psi it won't open the ports (obviously) but I can't understand why its not pumping at the right psi. I have even sprayed starting fluid into the carb to not have that do anything. Fuel pressure is keeps coming back all over the board, but all lower than it should be. what could be slowing down the fuel pressure at the fuel pressure test point? the gas is making it there just not fast enough. someone please give me an educated guess not an opinion. I'm single mother of 2 teenagers and NEED my truck!!!! please help me


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## octaneman (May 13, 2009)

Hi mrc9999

Good grief !

I nearly fell off my chair reading your post. Spending a fortune on all those parts without results is mind blowing. Tossing parts at it won't solve the problem if you can't narrow down what the main cause is. 

When it comes to fuel related problems here's what you need to know;


1) Fuel pressure fluctuations are usually the result of a bad fuel pressure regulator, faulty fuel pump, or a crimped fuel line. Since your fuel pump has already been replaced, what you will need to do is bring your truck to a qualified service tech and have them hook up a fuel pressure gage and pinch off the fuel return line. With ignition on (engine off) the fuel pressure should rise slightly above what the normal fuel pressure should be. If the mechanic see's that the pressure continues to fluctuate, then the problem lies within the main fuel line which was most likely placed in a bad position restricting fuel flow during the fuel tank's re-installation.

2) Another form of fuel restriction is when the fuel filter is put on backwards. 

3) Vortec engines come with a spider injector style system, the spider system is renowned to cause major problems because the fuel pressure regulator gives out and leaks over time giving a strong gas odor just before the engine dies. To replace the regulator the intake manifold must be removed and the intake gasket replaced or else the engine will never fire. There is also the problem of some after market suppliers of the fuel regulator that are defective and its recommended that OEM parts are used as replacements. 



Question: 

1) Did the engine suddenly just die when you were driving or was the truck parked and refused to start ? 

2) Have you put it on a scanner to retrieve any computer codes before or after the ECM was replaced ? 

3) Was there a smell of gasoline in the engine compartment *after* the engine initially died on you ?


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## mrc9999 (Sep 18, 2012)

Ok so 1 the truck has been acting funny and not staring right for 3 months. Very temperamental, turned over very hard and bogged like it didn't want to start not sure if that has anything to do with it. 2 there is no local certified mechanics anywhere near me and my truck doesn't move so I can't bring it anywhere. 3 I can test the fuel pressure myself only problem is its not getting the psi it needs, its hard to put a fuel filter on backwards when its labeled flow with an arrow?...the filter was changed in the spring and then again 4 days ago after the starting issues so I'm pretty sure thats not it. 4 The truck never has stalled and/or cut out while driving or at an idle so I'm not thinking its a crimp in the line I have run my hands and a dry rag over the whole fuel line so no leaks and no crimps to my knowledge. 
No to answer all 3 of your questions....no it didn't die while running it was running, and 4 hours later went out to start it to leave and hasn't started since...no codes have been thrown at all before or after the starting issue, it wasnt the ECM I replaced it was the ICM....and no.. no odor after the engine was last running
So where do I go from here.


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## octaneman (May 13, 2009)

mrc9999 said:


> Ok so 1 the truck has been acting funny and not staring right for 3 months. Very temperamental, turned over very hard and bogged like it didn't want to start not sure if that has anything to do with it. 2 there is no local certified mechanics anywhere near me and my truck doesn't move so I can't bring it anywhere. 3 I can test the fuel pressure myself only problem is its not getting the psi it needs, its hard to put a fuel filter on backwards when its labeled flow with an arrow?...the filter was changed in the spring and then again 4 days ago after the starting issues so I'm pretty sure thats not it. 4 The truck never has stalled and/or cut out while driving or at an idle so I'm not thinking its a crimp in the line I have run my hands and a dry rag over the whole fuel line so no leaks and no crimps to my knowledge.
> No to answer all 3 of your questions....no it didn't die while running it was running, and 4 hours later went out to start it to leave and hasn't started since...no codes have been thrown at all before or after the starting issue, it wasnt the ECM I replaced it was the ICM....and no.. no odor after the engine was last running
> So where do I go from here.



What you need to do is test the fuel pressure regulator. 

Leak down test : The first test is to do a leak down test to see if the regulator holds pressure. Hook up your fuel pressure gage and have an assistant with you to turn the ignition key on/off. Turn ignition on (engine off) a few times to build pressure within the lines. When line is pressurized look for any leaks from the gas lines to the engine compartment. Turn ignition off and observe the gage needle, the needle should drop approx 4-5 psi and then hold steady for about a minute. If the gage needle drops to 0 immediately after you shut off ignition then you have problem, either the injectors are leaking or its going through the regulator. If it doesn't drop to 0 then it passes the leak down test. 


If the fuel injectors and regulator pass the leak down test and the fuel pressure is still not building up to specs, the new fuel pump you put on is defective which needs to be replaced. 


Note : When replacing the fuel pump make sure the pump is seated in its proper position within the tank, and the pump screen is not being restricted or else it will draw in air instead of fuel.


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## riyarobin (Dec 26, 2013)

For your blazer to start properly you need 60psi pump pressure.


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## wolfen1086 (Oct 4, 2007)

Check the fuses and make sure they are intact also check on top of the tank where all the lines connect at, its entirely possible that one is bent just enough to ruin your day
( been there done that on a 89 )


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## Basementgeek (Feb 7, 2005)

This is a 15+ month old post, I bet they have it fixed by now.

BG


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## wolfen1086 (Oct 4, 2007)

WOW I didn't even notice the dates


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