won't run

[drivit]

i bought a new fuel pump for the throttle body
i'm sure buddy just sold me what he had in stock
the truck starts and idles for a second then stalls
if i touch the gas pedal it dies instantly
no change with new pump goodbye $100
it ran when i bought it
someone said i need fuel pressure
what else should i throw my money at?

[hotrod24]

when was the last time you changed the park plugs

[Fordeatinz71]

well, a new pump doesn't mean pressure.  you could have a bad fuel pressure regulator, clogged filter or a pinched line.  also, without being able to see it/hear it firsthand, it's hard to determine what your issue is exactly.  it might not be fuel pressure at all.  it could be, perhaps, the injectors aren't opening as they should.  injector pulse on the TBI motors are controlled by the ignition module, under your distributor cap.  they are about $15 and are easy to replace and die often.  you might also have a bad sensor.  you need to check for codes to see if there are any stored in the computer...you might get lucky and have the truck tell you whats wrong with it. 

[DnStClr]

Your post is a bit confusing. Why did you buy the fuel pump in the 1st place- was the engine not starting? What year truck do you have-an 87? The throttle body  wants to see a fuel pressure of @14-15 psi. If you bought a new electric fuel pump  I think you need to adjust the pressure with a pressure regulator so you wont be sending too much fuel to the throttle body.

[drivit]

it runs like a champ on spray start, so ignition is good
i agree and think its a pressure regulator/injector issue,
however the manual i have says regulator not servicable?
there's crud in everything for sure
i will try and clean /flush what i can
codes will require asking many favours
i'll keep trying thanks

[VileZambonie]

check your fuel pressure first. If it's good, check for injector pulse.

[drivit]

if it idles briefly do i have a pulse?
how do you check injector pulse?

[Fordeatinz71]

well, your regulator isn't considered serviceable.  but if it's bad you will need a new one.  to check for injector pulse you look while the truck is running, you should see a cone-shaped mist of fuel spraying off and on (rapidly) into the TB. 

[VileZambonie]

unplug the injector connector and use a noid light or a test light.

[Captkaos]

What are you working on?  Carb or TBI? 

Side note: The TB regulator is servicable, I did this to my 90 TB.

[drivit]

still trying just to get it running,
installed a new pressure regulator in the throttle body,
along with a new fuel pump in a bucket of fuel,
how do you pulse the injector to test it?
because it will run on spray start.

[TexasRed]

have you replaced the fuel filter?

[DnStClr]

the computer pulses the injectors- I'm not sure how you would do that. It happens very quickly, and the time that the injector stays open is called pulse width..(I think). I hope one of the knowledgeable GM techs helps out- this is pretty technical stuff.

[Captkaos]

Vile posted how to check for injector pulse, but if you want to check it another way, get your timing light and try to crank the truck and point the timing light at the injectors, it will pulse with every fire.  It is much easier with a test light or noid light.

If you do it in good daylight you can see them pulse.  Have you checked your fuel pressure as indicated way up at the top of the post?

[drivit]

thanks for hanging in there with me guys,
i'll keep trying all your suggestions.
i must repeat that this truck will no be going on the road.
it will recieve a total rebuild but i first need it to run,
in order to shunt it around all the other projects here.
so, the new pump draws fuel from a 5 gallon pail and
the lines exit the paessenger side vent window
under the hood to the tb. also i disgarded the fuel filter
thinking it might have been the problem, so the lines are short,
no filter but new pump and pressure regulator.
could i still have a pressure issue?
or my next move will be the ignition module and/or code reader as suggested.