Crank, No start Fuel pump or Spider fuel injector?

[Jake]

Hello I have a crank no start issue on my 99′ S10 4.3.

A few months ago, the fuel pump was making loud noise so i replaced it and the truck has been running great until yesterday.
I tested for spark which is good.
I can hear the fuel pump engaging when i turn the key.

Before i go in too deep i’m going to have the battery checked and test fuel pressure.

I’m wondering if i test fuel pressure, how could i tell if the issue is with the fuel pump or injectors? I’m only wondering because i wiped down the throttle blade (some obstructing build up). I wiped my finger inside and it’s caked thick with build up.

I’m a bit of a newb so let me know if I’m approaching this all wrong :silly: Thanks

Topic

[college man]

On the spider injection the injectors are not electric. They are basically an orifice.
Unless everyone is clogged doubtful check the fuel pressure. see if this helps.

http://troubleshootmyvehicle.com/gm/4.3L-5.0L-5.7L/testing-the-spider-fuel-injector-1

[Donald]

when you replaced the pump did you also replace the fuel filter…. it could simply be clogged.

[Jake]

I did not replace the fuel filter at the time… I got my battery back, tested ok. i also got a fuel filter it was only 12 bucks. I just finished replacing the fuel filter and it had some trouble until i floored the gas pedal and the engine fired right up! The old filter had some dirt in it so it looks like that was the issue.

I’m still losing some fuel pressure during the initial startup and i have to hit the gas pedal in order to get it going. Any other ideas? Thanks for the help!!!

[none]

The fuel pressure regulators are known leakers on the spider injectors. If it’s letting the fuel pressure bleed down far enough, it will cause long crank times. Instead of flooring the gas pedal, try cycling the key on and off a couple times and then crank. Your truck will run the fuel pump for two seconds to prime the fuel pressure every time you key on. If you cycle the key a couple times first and the truck fires right up when you do crank, it’ll point to the regulator being bad. This is usually only good for cold starts unless that regulator is really shot.

If you have long crank times no matter when you’re cranking (cold or hot startups), then you’re more likely to be chasing down a vacuum leak or a weak fuel pump. I know you’ve already replaced the pump, but it’s not unheard of to get a dud fuel pump out of the box. The pump itself could have a bad check valve letting fuel pressure bleed off too.

Some more time with that fuel pressure gauge will answer some of your questions for you. Pay attention to and record fuel pressure with the key on before you crank, engine running fuel pressure, and then finally watch to see if the fuel pressure bleeds down once you shut the key off.

Start with that, if you like, and let us know what you find.

Good luck.

Oh, and pull that throttle body off, clean it out including the IAC passage. That’s a job worth doing even if it doesn’t solve any immediate problems.

[Author]

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