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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.
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Have weak yellow spark to plugs, 1991 chev k 1500, coil

Customer Question

have weak yellow spark to plugs
JA: What is the model/year of your Chevy?
Customer: 1991 chev k 1500
JA: Are you fixing your vehicle yourself? What have you tried so far?
Customer: coil plugs wires cap rotor module and pickup
JA: Have you checked all the fuses? Do you have a wiring diagram?
Customer: checked all fuses in fuse box under dash do not have wiring diagrahm
JA: Anything else you want the mechanic to know before I connect you?
Customer: no
Submitted: 8 months ago.
Category: Chevy
Expert:  Gary replied 8 months ago.

Welcome! My name is ***** ***** I will do my best to assist you with this problem.Ask me about added features such as phone contact anytime if you wish !

Expert:  Gary replied 8 months ago.

I am assuming this is a 5.7 engine and it cranks over and does not fire up ?

Customer: replied 8 months ago.
Expert:  Gary replied 8 months ago.

can you confirm with the key ON unplug the ignition coil does 1 wire terminal show a confirmed 12 volts with the key ON ?

Customer: replied 8 months ago.
will check
Customer: replied 8 months ago.
11.64 volts on wire
Expert:  Gary replied 8 months ago.

when cranking it over there is a good fuel pulse out of both injectors and it will not somewhat run on starting fluid ?

Customer: replied 8 months ago.
it has a edelbrock after market fuel injection will not fire on starting fluid have weak spark at plug and can smell fuel
Expert:  Gary replied 8 months ago.

what distributor are you running and coil?

Customer: replied 8 months ago.
stock hei that came on 91 chevy also has 40 psi static pressure at rail
Expert:  Gary replied 8 months ago.

ok so the HEI big power wire showed 12 volts with the key ON ? what does it show cranking it over ?

Customer: replied 8 months ago.
will check to see what voltage is when cranking
Customer: replied 8 months ago.
8.43 volts when cranking
Expert:  Gary replied 8 months ago.

if you run a wire right from the positive battery cable to that distributor will the spark be better cranking it over ?

Customer: replied 8 months ago.
ok will try that
Expert:  Gary replied 8 months ago.

ok

Customer: replied 8 months ago.
will talk later the guy I was helping has to go get his kids will talk later thank you jerry potter
Expert:  Gary replied 8 months ago.

ok sounds good

if that does not work and it will not run on starting fluid

is the distributor in correctly ?

what is the compression on the engine are the cylinders above 125 PSI ?