350 TBI starting issues....

[Christian Sullivan]

Alright I'm stumped on this one.... It seems to be only on cold mornings, and it doesn't do it once the truck has been driven for 15-20 minutes.

Most times it will turn over and run for a second or so and then die, give it a little gas when cranking and she fires right up, let her idle 5 minutes or so and I'm on my way. Got out of work this morning and It would just crank and crank, no start atall, even when giving it a little gas. After about the 6th time while giving it gas she started, ran really rough for 10-15 seconds and all was good. Drove home, killed it, and cranked right back up. When you turn the key on you can hear the fuel pump kicking in, New engine coolant temp sensor added about a week ago. Maybe fuel pump getting week? If y'all have any ideas it would be greatly appreciated!

94 Chevrolet 1500, 2wd Auto, 350 TBI, 270k miles

 

[mike550]

Check the fuel pressure regulator, does it ever die on its own? When I rebuilt my intake, (5.7 tbi) I didn't get a good seal on the fuel pressure regulator, and it ran like ****.

 

[Christian Sullivan]

Check the fuel pressure regulator, does it ever die on its own? When I rebuilt my intake, (5.7 tbi) I didn't get a good seal on the fuel pressure regulator, and it ran like ****.

When I stop at redlights sometimes she acts like she's gonna bottom out on rpm, will drop to 3-400. I'll look into that, thank you

 

[Eveready]

My bet is on the fuel pump, distasteful as that may sound, especially since it is episodic on cold mornings. An outside possibility might be an electrical issue, low battery etc since on cold mornings you are more likely to use more electricity running the heater.

If you can duplicate the problem on a warm day with fan on high and full headlights on, then it might be electrical. I would try it with a good battery to rule that out and then start looking for the bed bolts.

 

[Christian Sullivan]

My bet is on the fuel pump, distasteful as that may sound, especially since it is episodic on cold mornings. An outside possibility might be an electrical issue, low battery etc since on cold mornings you are more likely to use more electricity running the heater.

If you can duplicate the problem on a warm day with fan on high and full headlights on, then it might be electrical. I would try it with a good battery to rule that out and then start looking for the bed bolts.

Don't have a heater, and I start it with all lights off, but I see where you're coming from.. thankfully the fuel pump is only $50 from O'Reilly's, so that's not going to kill me. Only part that sucks is I live on a military base so I have to take it to the self service shop on post and pay $15 an hour for a bay...

 

[Dropped88]

Next time barely press the gas pedal to crack the throttle open just a litte and she if itll fire up better and idle better sorta sounds like your IAC is sticking

 

[arrg]

Don't have a heater, and I start it with all lights off, but I see where you're coming from.. thankfully the fuel pump is only $50 from O'Reilly's, so that's not going to kill me. Only part that sucks is I live on a military base so I have to take it to the self service shop on post and pay $15 an hour for a bay...

Dude, go spend the $15/hr for a bay with a lift. You could have it replaced in less than 2 hrs if you stop for lunch half way through.

 

[Eveready]

Since you are going to be highly pissed as well as out some money if you replace that fuel pump and it still misbehaves I would eliminate electrical issues first. The bit about the blower and lights is to see how it does with lots of power being used vs almost none.

A bad connection at the battery or the starter end could mimic some of the issues you are having. Only then would I go after the fuel pump.

 

[evilunclegrimace]

Borrow or rent a FP gauge before you fire the parts canon. See if your TPS is acting the way it should.
Is the CTS reading with 5 degrees of air temp on a cold engine?
Have you changed the fuel filter ?
How about the fuel pump relay? test it yet?
Bad cap and rotor? Moisture in it?
Bad plugs?
Have you done an EST by pass test?
Sticky EGR valve?

 

[evilunclegrimace]

Next time barely press the gas pedal to crack the throttle open just a litte and she if itll fire up better and idle better sorta sounds like your IAC is sticking

Even if the IAC is stuck fully extended it should start and idle.

Alright I'm stumped on this one.... It seems to be only on cold mornings, and it doesn't do it once the truck has been driven for 15-20 minutes.

Most times it will turn over and run for a second or so and then die, give it a little gas when cranking and she fires right up, let her idle 5 minutes or so and I'm on my way. Got out of work this morning and It would just crank and crank, no start atall, even when giving it a little gas. After about the 6th time while giving it gas she started, ran really rough for 10-15 seconds and all was good. Drove home, killed it, and cranked right back up. When you turn the key on you can hear the fuel pump kicking in, New engine coolant temp sensor added about a week ago. Maybe fuel pump getting week? If y'all have any ideas it would be greatly appreciated!

94 Chevrolet 1500, 2wd Auto, 350 TBI, 270k miles

Holding the throttle pedal while cranking tells the computer to increase injector pulse width (add more fuel) and this can cause a flooding issue.