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5.0 Gi throttle body injected engine dies right after start up/fast idle

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stang32

Regular Contributor
hey all, i got this engine giving me trouble, it is throttle body injection and the pressures are ok, 6psi, low pressure and 29 psi on the high pump
i see a pattern coming out of the injectors but thats all i can tell on that end. i can keep it running indefinitely if i supplement the gas with light sprays of starting fluid. so its not spark related. could the injectors are restricted?
as i sit here i am also wondering if it could also be bad gas. the problem became evident last fall during winterizing and i forgot about it till now. never had a problem with gas from where i get it from on the lake before so hard to believe thats the issue. ill pull a sample later and see what i come up with meanwhile ,f anyone has any ideas. pleas chime in
 
stang32 said:
hey all, i got this engine giving me trouble, it is throttle body injection and the pressures are ok, 6psi, low pressure and 29 psi on the high pump
i see a pattern coming out of the injectors but thats all i can tell on that end. i can keep it running indefinitely if i supplement the gas with light sprays of starting fluid. so its not spark related. could the injectors are restricted?
as i sit here i am also wondering if it could also be bad gas. the problem became evident last fall during winterizing and i forgot about it till now. never had a problem with gas from where i get it from on the lake before so hard to believe thats the issue. ill pull a sample later and see what i come up with meanwhile ,f anyone has any ideas. pleas chime in
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I would avoid using starting fluid, prefer gas. I use a squeeze bottle from mustard with adjustable nozzle for this, to prevent too much coming out. Starting fluid is too volatile to be safe.

It's easier to see the spray pattern if you have a timing light- shine it on the fuel and squeeze the trigger, to see a 'freeze frame'. It will look stationary. If it has any gaps (that's called 'tearing'), it could be a dirty injector, low pressure or possibly the regulator.

Did you purge the air from the fuel pressure gauge's hose before testing? Assuming it has a purge valve, this is a great time to take a fuel sample.
 
Injectors continue to spray but motor starts to die, and only keeps running with a bit of starting fluid?

Without a scanner I would try fresh gas. Empty all parts and refill with fresh from a portable source
 
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