Fuel injectors

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  #1  
Old 03-20-13, 03:02 PM
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Fuel injectors

Can someone tell me how to test the fuel injectors when the engn
ine will not start. The engine is turning over, have sparks to plugs, checked the fuel check on the back of engine and the new fuel pump is pumping gas but sounds like the gas and spark are not getting together
 
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Old 03-20-13, 03:59 PM
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Go to get it analyzed to find out the problem if you can get it to run. I t will be faster and cheaper. - I have had that problem until I decided not to be stubborn.

There are many types of cars with injectors from throttle body to sequential with six or more injectors and many coils and there are many other possibilities.

Dick
 
  #3  
Old 03-20-13, 05:44 PM
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fuel injectors

2000 Blazer need to know how to check fuel injectors to make sure the gas is getting to them. Cannot get it to run so cannot take to shop right now.
 
  #4  
Old 03-20-13, 06:40 PM
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If gas and spark are not getting together, you have:
1. wrong timing
2. plugs flooded with gas from attempts to start. Take couple of them out, and smell them. If they smell of gas - well, you have you question answered and if they are WET with gas, they won't produce reasonable spark. Take butane torch to the tips, until they are white, then put them back in and try starting again. If they caome out nice dry and clean - well, you got your question answered too, right?
 
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Old 03-20-13, 07:32 PM
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Fran108,

Post the year, make, model, engine size and mileage of your vehicle, so that accurate repair information can be posted for you. There are quite a few reasons for a no start condition that have NOTHING to do with spark and fuel delivery. The answer to your fuel injector question is to use a tool called a "Noid Light" to confirm that the injectors are firing. You can borrow a "Noid Light" for FREE from an Auto Zone store via their "Free Loaner Tool Service".

Thank You
Amy
 
  #6  
Old 03-20-13, 07:46 PM
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a 2000 blazer does not have normal injectors. they have what you call pop-it valves. they need at least 50psi to open. have you put a gauge on the fuel system?
 
  #7  
Old 03-21-13, 05:12 AM
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Can also do a quick check using aerosol carb cleaner. While someone cranks it, spray a mist of the cleaner into the intake. Use the little extension tube so the spray atomizes sufficiently and don't overdo the amount you shoot in. You should at least get a few coughs and sputters if everything but fuel delivery is working. An experienced mechanic with the right touch can keep one running at a rough idle, but all you really want to know is that it will fire and try to run.
 
  #8  
Old 03-21-13, 09:59 AM
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Fran108,

Seems like I have to get a refund on the speed reading course I took (LOL). Sorry, but I didn't see your posting where you stated your vehicle is a 2000 Blazer.


The 4.3 engine in your Blazer likes fuel pressure. The “Spider” is a mechanical valve fuel injector system, that uses fuel pressure to operate and open the valve(s).

A central fuel control valve is opened electronically and allows fuel (under pressure) to the mechanical poppet valves (aka injectors).

This fuel pressure is what opens the injectors. The principal of operation is like an old diesel style injector set-up. worked.

50 PSI is not enough fuel pressure to open the injectors. It specs out at 55 to 62 PSI.

Possibilities:

Fuel filter is clogged up.

Fuel pump is defective.

Fuel pressure regulator issue.

Even when the injector system is working correctly there are still going to be future issues due to the "Mechanical Poppet Valve" set-up. With that being said you should strongly consider the "MFI" conversion below.

GM Parts Direct: pk12568332 - SCPI to MFI upgrade kit for 4.3 V6

Thank You
Amy
 
  #9  
Old 03-21-13, 07:02 PM
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I can attest to the problem with no starting a 4.3L engine.

My 1999 Jimmy was "bullet proof" until one morning, I went to the Drug store 6 blocks from my house. When I came out it would not fire. My mechanic was 2 blocks away and pulled me back to his shop. After asking what the problem was, he said it was probably the fuel pump and I only had 150,000 miles on it. He explained that fuel pressure is critical on that set-up and will not run if it is even 1 or 2 psi too low. He had to replace his wife's Blazer at 125,000 and his son's Blazer at about the same time, so I got away longer at 150,000 miles. It is not a 5 minute replacement and the pump is not cheap.

Now all I have to do is worry about my wife's 2000 Blazer with 125,000 miles. - Maybe I should have hers done while I am aware of the eventual problem and avoid the breakdown and towing if she is not close to my mechanic that is reasonable and very honest.

Dick
 
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Old 03-22-13, 03:49 AM
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Maybe I should have hers done while I am aware of the eventual problem and avoid the breakdown and towing
Naw, Dick, wait until she is caught in a snow bank in outer Mongolia, Minnesota I agree with the PM on the vehicle, totally. Just in jest!
 
  #11  
Old 03-22-13, 04:11 AM
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....avoid the breakdown and towing
Nah, be daring!!!
 
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