fuel cut?

[cwilson jr]

the other day everytime i would go up inclines, my motor would cut out and i would have to play with the pedal to keep it going.  after a few times of this it stranded me.  it wasn't getting fuel in my clear fuel filter housing before the carb. and when it would, it would not completely fill and there would be air and bubbling as well.

i changed the fuel pump and the filter housing filled up, no air and stayed running fine while in park for a while.  took it down the road a few miles and started doing it again on the flat and eventually several miles later on the way home it stranded me again.

i changed the fuel filter now and when i give it gas while in park, it seems like every 2-3 revs it has a cut out.

what else could this be? i have my filter right before the carb and before that, there is only the sending unit and pump.  had the sending unit out about a month ago.  don't see an issue there.  i don't know what else could this be, unless there might be something else going on as well.

[74 C-10 Shorty]

Make sure the tank is adequately vented first thing.

[cwilson jr]

ok, at the moment it seems to be running "almost" fine during normal driving.  it had two very minor cut outs while pulling out one time, other than that took it up a long steep hill by my house 3x and a somewhat lengthy trip with no issues whatsoever.

however, while parked, and revving it up, it still cuts out maybe every 3-4 times, other than that sounds absolutely perfect AND while heading down the road, gunning it, it will sound just awful, it sounds very sickly and has no power, like its starving for fuel or air.

idles perfect.  what could be the next thing i look at?

[74 C-10 Shorty]

So, did you make sure the tank is vented?, easy way to tell is take the cap off and make a run, if it runs good with the cap off then it's a vent issue.

[cwilson jr]

sorry for the delay, had a few projects going on.  here's what i have happening at the moment on my 1985 k10 350:

an overall miss?

there is a total cut-out/dead spot of the engine sometimes while initially pressing the accelerator anytime when cruising.  haven't tried this while idiling in park yet, and a vibration anytime while having the gas pressed when crusing.  i would describe the vibration as in the whole truck shaking/bucking.

i have so far:
inspected sending unit
replaced the fuel pump
replaced the fuel filter
replaced air filter
removed gas cap


what i could look into next?

[Irish_Alley]

do you have a soc on the fuel tank sending unit? have you replaced that? hows the rubber lines that lead to the fuel pump?

[Fairlane514]

Take the carburetor apart and check your float level. Sounds like the carburetor is running out of gas and then catches up. If its a quadrajet there is also a fuel filter in the inlet, it may be clogged.

[74 C-10 Shorty]

Those filters plug up easy, I always throw them away and put a good inline filter in.

[Irish_Alley]

we did have a discussion on why they glass/clear filters dont fill up all the way and how its normal but bubbles? that would be air in the system and thats the part im not sure about

[cwilson jr]

everything is good on the sending unit/sock and fuel hoses.  i went back to my external fuel filter setup and have eliminated the "dead spot" and the only issue i have now is a large miss remaining.

i have noticed it idiles weakly when warmed up and it cruises fine for the most part, except for when i'm holding the accelerator down while cruising, maybe 1/4 of the way down, which i'm good until immediately when it kicks into 2nd gear, then it starts missing horribly and bucks/shakes the entire truck.  this is on completely level ground.  it runs like crap going uphill as well, but have completely eliminated "dead spots" and cutting out.  i'm left with thinking theres something going on with the fuel delivery in the carb?  i'm going to look into the float as mentioned above.  what else can/should i be looking at?

this is on an 85 k10 350/auto with qa q-jet

[zieg85]

Just a thought... Do you still have the 305 distributor with the ESC system?

[cwilson jr]

it was an originally a 305 truck with the esc system.  that i do know.  now, i remember talking about the subject with a guy, but that was many years ago and i dont recall alot on it.  is that something that can be on there originally which i know it was and not used now or if it's on there it's being used?

[zieg85]

The easiest way to find out is to see if there is a second plug coming from the distributor going into the wiring harness.  There is a way to bypass it but I don't remember which 2 wires you have to jump.  (that is if you still have it and it is still hooked up)

[454Man]

Wires black and green. Splice together

[cwilson jr]

ok, so i'm looking the diagram posted below in the link and if i'm looking at it correctly, it looks like the esc would be on the left-hand side and towards the rear, if you were standing as you just opened the hood?

there is no connections, plug or harness back there, so, i would assume that i have hei already?



http://i6.photobucket.com/albums/y228/Sabaka454/esc82.gif