Starting Issues TBI 350

[Jake292]

The past few days my truck has had some issues starting. When I first turn the key it fires right up but within a few seconds it sputters and dies; it doesn't matter how much gas I give it. Then when I try to start it again it has to crank for a while and, with the throttle is half way open, it will begin to fire and it clears the fouled plugs and runs fine.

For a while it has died when under an load at idle for a few minutes, like in drive at a stop light. I have been just power breaking it a little bit and it hardly ever dies on me.

 

[89Suburban]

Do you think it is flooding with too much fuel? That's what it sounds like to me.

 

[skysurfer]

lol, I was thinking just the opposite and that the fuel pump is going bad. This is where a pressure gauge mounted in the fuel line comes in handy.

 

[MrMarty51]

My answer to everything. O2 sensor. LOL

 

[89Suburban]

My answer to everything. O2 sensor. LOL

You must be registered for see images attach

 

[Jake292]

it seems more to me that it is running out of fuel. The O2 Sensor is new. Will pull codes this afternoon.

 

[89Suburban]

We got to whip up a vendor on here that sells an affordable fuel pressure tester just for these TBI trucks.

 

[Jake292]

We got to whip up a vendor on here that sells an affordable fuel pressure tester just for these TBI trucks.

yeah $50 aint worth it.

 

[89Suburban]

Might be that damn rubber hose on the pump in the tank.

BTW, if you wind up doing anything with the fuel pump keep this place in mind:

http://www.tanks-to-pans.com/

 

[MrMarty51]

Might be that damn rubber hose on the pump in the tank.

BTW, if you wind up doing anything with the fuel pump keep this place in mind:

http://www.tanks-to-pans.com/

Added that one to Mine favorites, thanks.

 

[bucket]

Pull a few plugs and see what they look like.

 

[Jake292]

Attached is the Tunerpro file, if it helps.

The only error codes that I saw was high map and EST. if the map sensor is still under warranty, I will replace it.

I found parts to do an inline fuel gauge that adds up to 25 bucks, going to do it this week.

 

[Jake292]

it wont let me upload the file like it used to

 

[Jims86]

High voltage is usually a vac leak, or looowwwww.
Check the reference voltage supply at pin C of the MAP sensor (gray wire typically). Measure voltage between pin A (ground) and Pin C (+5 V ref) with a DVM. It should be right around 5 Vdc. With Key on engine off the MAP voltage (Pin B, light green wire typically) should read around 4.8 to 4.9 volts. If it reads the same as pin C the sensor is probably is history. Also check ground reference pin A. With everything off, measure resistance between Pin A and electrical ground (stud next thermostat). It should be fractional ohms.

Another functional check – with engine idling MAP output voltage (depending on idle vacuum) should be in the neighborhood of 1.2 to 2.0 volts. If it is stuck at 5 volts, check grounds and most likely MAP sensor is history.

 

[89Suburban]

it wont let me upload the file like it used to