How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask GM Tech (Cam) Your Own Question
GM Tech (Cam)
GM Tech (Cam), Chevy Technician
Category: Chevy
Satisfied Customers: 15201
Experience:  GM Grand Master Technician 2007. 14 years experience.
10949255
Type Your Chevy Question Here...
GM Tech (Cam) is online now
A new question is answered every 9 seconds

Chevrolet S10 4x2: 1995 s10 will not run. After a lot of cranking

Customer Question

1995 s10 will not run. After a lot of cranking it will start
sometimes but only run a few seconds and shut off. I have replaced the
fuel pump and fuel filter. Checked for battery voltage at the relay and
pump, they are battery voltage. I had a code 54, relay but it functions
as it should.
Submitted: 2 years ago.
Category: Chevy
Expert:  Gary replied 2 years ago.
will the engine run on starting fluid or carb cleaner being sprayed into the butter fly ?
Customer: replied 2 years ago.
Yes, it will run on carb cleaner. I am wondering if it may be the oil pressure switch. The gauge work just fine.
Expert:  Gary replied 2 years ago.
the oil pressure gauge will just run the fuel pump if the computer can not control the fuel pump relaycan you see what the fuel pressure is when it will not start key ON engine OFF ?if you unplug the fuel pump relay and jump the orange terminal wire to the grey wire terminal will the truck run ?
Customer: replied 2 years ago.
I do not currently have a large enough piece of hose to test the fuel pressure. On the relay, I cannot see behind so I cannot determine wire color. I do know the top two terminals are battery voltage. That leaves the bottom two terminals, which is which?
Expert:  Gary replied 2 years ago.
on the relay are there little numbers that show which terminal is which on the relay ?if so you want to jump #30 to # ***** in the box the relay plugs into and that should hot wire the pump to runand see if the truck will run
Customer: replied 2 years ago.
See the attached image of the relay. The pins are only labeled with 1-5.
Pins 2 & 3 are battery voltage. By the image it looks like to jump it would be pin 2 or 3 to pin 5, correct?
Expert:  Gary replied 2 years ago.
3 to 5
Customer: replied 2 years ago.
I connected jumper between 3 and 5, the fuel pump runs. It only started once and died after a few seconds.
I'll get the fuel pressure test done tomorrow unless you can think of anything else.
Expert:  Gary replied 2 years ago.
so the pump will run when jumped even when it dies the pump is running ? if so we need to be sure we have enough fuel pressure next
Customer: replied 2 years ago.
Yes, it dies even when the pump is running. 42 psi, tested it three times and it holds pressure.
Expert:  Gary replied 2 years ago.
can you keep it running with carb cleaner or starting fluid ?
Customer: replied 2 years ago.
Yes, it will keep running on carb cleaner. I had already tried this as you suggested.
Does the 95 model year have a passlock system?
Expert:  Gary replied 2 years ago.
no it does noti am wondering if you are looking your injector pulse can you see when it will not run if you have an injector pulse with a noide light while cranking it over ?
Customer: replied 2 years ago.
I tested with a noid light just on one cylinder and it appears to be pulsing correctly.
Expert:  Gary replied 2 years ago.
the other 3 are not ?do the none pulsing injectors with the key on show 12 volts on one of the terminals in each connector ?
Customer: replied 2 years ago.
I was able to pulse check #2, #3, & #4. All tested good for pulse. I cannot access #1 without some removal of the intake.
Customer: replied 2 years ago.
Okay, it's been almost 3 days, is anyone going to reply??
Customer: replied 2 years ago.
As per the wiring diagram the oil pressure switch is part of completing the circuit. I replaced the oil pressure switch, it will run a few seconds longer now but still dies even with the the fuel pump relay being by-passed.