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AMEDEE
AMEDEE, CHEVY TECHNICIAN
Category: Chevy
Satisfied Customers: 24447
Experience:  ASE certified tech ADVANCED LEVEL SPECIALIST. Wisconsin certified emissions state inspector
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1990 chevy: s-10 with the 4.3l v6 and fuel injection..injectors..carb

Customer Question

Have a 1990 chevy s-10 with the 4.3l v6 and fuel injection. there is no gas coming thru the injectors to the carb. If it sits for 3-4 hours it will start. It will then run for a while but then die unexpectedtly after a day or two.
Submitted: 5 years ago.
Category: Chevy
Expert:  AMEDEE replied 5 years ago.
Hello!

Do you happen to know what the fuel pressure is at when it does not start?
Customer: replied 5 years ago.
No I do not know.
Expert:  AMEDEE replied 5 years ago.
SO it has spark when this happens?

It does run on starting fluid when this happens..correct?
Customer: replied 5 years ago.

How would I check that it has spark?

 

We have not put starting fluid in it

Expert:  AMEDEE replied 5 years ago.
Disconnect #1 ignition wire at the spark plug.
Install a spark tester into the end of the spark plug boot.
Have an assistant crank the engine over and check for spark at the tester.
Repeat this process at each spark plug.
If any cylinder does not show spark, proceed to secondary component tests.
If ALL secondary components show no spark, test components individually.
If all cylinders test O.K., inspect for fouled spark plugs and clean or replace as necessary.

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Customer: replied 5 years ago.
I am pretty sure that it has a spark. There is no fuel going into the carb. what does one have to do with the other?
Expert:  AMEDEE replied 5 years ago.
This is because if there was neither spark or fuel, then chances are the computer is not even awake. If there is just not fuel, then you might just have a fuel pump or wiring problem. I would recommend to start by checking fuel pressure if the spar tests checks out. Fuel injected cars are very fuel pressure sensitive. Fuel pressure is very important and must be within specifications! But if the pressure is low, it does not mean the pump is bad. A plugged fuel filter, a pinched line, and low voltage at the pump can contribute to low fuel pressure. All three must be check before replacing the pump! Fuel pressure testing is frequently overlooked but it is one of the common causes of poor performance and hard/no start conditions.

Customer: replied 5 years ago.
what do I need to test the fuel pressure?
Expert:  AMEDEE replied 5 years ago.
Sorry for the delay!

You just need a fuel pressure gauge with the correct adapter to screw into your fuel rail and you should be good to go. Once you got the correct tools, just install the fuel pressure gauge and turn the key on and take a fuel pressure reading.

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