Truck having trouble starting

[Obssean]

Sounds like the IAC passages are plugged, not getting enough air to run. Opening up the throttle gives it air.
Pull out the IAC, clean thoroughly, reinstall and perform an IAC relearn.

It’s not all the time though. It seems to happen at random.

 

[stutaeng]

Is there a good way to check that?

Yes, with an inexpensive fuel pressure guage. Hook it up and turn the key on, but not cranking engine. Now check pressure gauge. Come back 15 minutes later and see guage. Should only be a few psi lower. A leaky FPR will cause pressure to drop significantly.

 

[Obssean]

Yes, with an inexpensive fuel pressure guage. Hook it up and turn the key on, but not cranking engine. Now check pressure gauge. Come back 15 minutes later and see guage. Should only be a few psi lower. A leaky FPR will cause pressure to drop significantly.

I can go grab one after work tomorrow. Where would be a good place to hook it up?

 

[stutaeng]

There's

I can go grab one after work tomorrow. Where would be a good place to hook it up?

There's a Schrader valve in the intake.

A fuel pressure guage as well as a vacuum guage are invaluable diagnostic tools a lot of folks don't own. In my experience they are must-have tools.

Keep us posted.

 

[ColoradoMadMan]

I have a 1998 Gmc K3500 with the 454(7.4) big block. For some reason that seems to be at random the truck will not start without me pressing on the pedal a few times. If I don’t give it gas it will just sit there and crank. Not a huge deal i’m just curious why this is happening and can’t find any info on it. Any ideas?

I used to need to feather the throttle to get my 98 K1500 to start. Got worse over three years. Finally put a fuel gauge on it and found I’d have over 50 psi for about 1 second then would drop to 45. Took many times before the engine would fire before it dropped. (The poppets won’t work under 50 psi). Replaced the fuel pump and it starts better than new.

 

[Obssean]

There's


There's a Schrader valve in the intake.

A fuel pressure guage as well as a vacuum guage are invaluable diagnostic tools a lot of folks don't own. In my experience they are must-have tools.

Keep us posted.

So a little update I had a lady smack into me mid turn and crunched the bed and cab corner. Currently waiting for insurance to review everything and go from there. If the truck isn’t totaled I will look into this issue further but right now I just have to wait until early next week to hear more. Insurance is taking their sweet ass time as usual.