C30 farm truck, runs but wont re-start

[sr54x4]

first post here, applogize if its in the wrong section.

i have a 1989? gmc c30 dump. I put it here since it is still a square body being a 1 ton. i believe it has the 350 in it. its a farm truck, hauls the you know what from the stables to the far side of the property (1/3 mile or so) to be dumped when ever it gets full of you know what. usually about once per month.

aside from having a dead battery almost every time, it always starts right up. it runs rough and doesnt idle. the problem is, if you let the engine stall out it wont start back up again unless it sits for 24 hours or so.

it does stall often, simply because it is a manual trans, doesnt idle, it has a PTO to dump that needs to be engaged, terrible brakes, no parking brake, dump area is on an incline, etc. and i only have two feet to get all this done! remember its a farm truck, so getting all this stuff fixed is not going to happen.

i would love to figure out why it wont restart after running. i have replaced the cap and rotor as well as ignition coil, no luck. it wont re-start on starting fluid either. usually you can smell gas, so i am thinking it is getting vapor locked or flooded out? are there any simple tests i can do to help narrow it down? driving it out to the dump area and towing it back to the barn with my truck is starting to get old.

thanks in advance!

[clapage6]

sounds like it could either be flooding since it is running etc. or possibly starved for fuel also.

is this a tbi 350 truck?

[sr54x4]

Originally Posted by clapage6

sounds like it could either be flooding since it is running etc. or possibly starved for fuel also.

is this a tbi 350 truck?

not really sure to be honest. how can i tell? i am new to this truck. as long as it is running, and you keep a your foot on the throttle a bit, it will run for as long as you need it to....

[clapage6]

Originally Posted by sr54x4

not really sure to be honest. how can i tell? i am new to this truck. as long as it is running, and you keep a your foot on the throttle a bit, it will run for as long as you need it to....

oh no worries. TBI would be fuel injected and is most easily identifiable in my opinion by the large aluminum intake manifold and no carburetor of course.

if tbi: there could be quite a few issues that I'm sure people here could help you with causing your symptoms.

if carbed: it's a simple float adjustment or needle/seat clean most likely.

[old Rusty C10]

get a can of gumout and clean the heck outta the carb or tbi im betting that if its original its tbvi but im still thinking its flooded... Hudson Valley eh? I am from NYC and now live in nj but still go through there alot

[sr54x4]

Originally Posted by clapage6

oh no worries. TBI would be fuel injected and is most easily identifiable in my opinion by the large aluminum intake manifold and no carburetor of course.

if tbi: there could be quite a few issues that I'm sure people here could help you with causing your symptoms.

if carbed: it's a simple float adjustment or needle/seat clean most likely.

I thought thats what you are referring to. It is a carbed motor.

Originally Posted by old Rusty C10

get a can of gumout and clean the heck outta the carb or tbi im betting that if its original its tbvi but im still thinking its flooded... Hudson Valley eh? I am from NYC and now live in nj but still go through there alot

I will try to do a cleaning on it then. That seems like good place to start. Do I need to take the carb off or can it be done with the carb on?

and yes, im outside Poughkeepsie in the Millbrook area if you are familiar.

[mrolds88]

Since it's carbed, try this. Pull the air cleaner lid and see if the choke flap is closed. If it is closed all the way, take a wood/spring clothes pin and hold the choke open, then make your run. See how it acts. Also then check to see if the electric choke is getting power. Should be a green wire on the round black piece on the passenger side of the carb.

[sr54x4]

Originally Posted by mrolds88

Since it's carbed, try this. Pull the air cleaner lid and see if the choke flap is closed. If it is closed all the way, take a wood/spring clothes pin and hold the choke open, then make your run. See how it acts. Also then check to see if the electric choke is getting power. Should be a green wire on the round black piece on the passenger side of the carb.

Great idea! that would make perfect sense that the choke isnt working and staying closed. it would explain why it wont idle and wont re-start until its cold again. I only am able to get to the truck in daylight hours on the weekends, plus its 5 degrees out lately. I will try to check that out this weekend.

[old Rusty C10]

since we have confirmed carb definitely check that choke.. and clean it the new gas kills carbs gums them up etc..

[sr54x4]

Originally Posted by old Rusty C10

since we have confirmed carb definitely check that choke.. and clean it the new gas kills carbs gums them up etc..

whats the best way to clean it with the gumout/carb cleaner? do i just leave the carb on and while the truck is running spray some in there? or take the carb off the engine and then clean it?

[mrolds88]

Actually both. Initially you can do some cleaning on the engine. Running. Just watch, if you get too much going in the engine it will load it up and shut it off. Just makes it a pain to restart. I would turn up the idle screw while doing this. You can pull it off and do a more thorough cleaning with it off.

[clapage6]

you should also be able to tell if you have a float issue while the truck is running with the air cleaner off.

Shine a flash light inside it while truck is running and look for fuel dripping or pouring inside. It will be obvious... and definitely causes conditions like you're describing.

[sr54x4]

thanks for all the input. I will try and get to the truck this weekend if it doesnt rain (supposed to) and report back.

[sr54x4]

Well, big mistake on my end. It's TBI, not carb. Sorry for the confusion. For the record i don't own the truck, it's part of the barn we rent. So what can I look into now that we know its TBI?

[rs74]

What about the pickup coil? When it dies have you ruled out that it may be a firing issue?

[buddy_1]

Still sounds like it's flooding out. Next time it stalls out, try holding the accelerator pedal to the floor. See if it will restart, might have to crank on it a bit. I have seen the fuel pressure regulators leak and cause them to flood. The regulator is in the throttle body, go here

Rebuilding and modifying a GM TBI Fuel Injection...

for a video on how to replace it if needed. In the video he is modifying it to be adjustable which you shouldn't need to do but it gives you the basic procedure. Another thing is you don't have to remove the throttle body to replace the regulator it can be done on the engine. I just remembered you should also check the ECT (Engine Coolant Temp) sensor reading with a scanner, if it is bad it can tell the ECM that it's -35F degrees outside. Don't know how much that could affect it in NY but here in southeast Tx it can make a huge difference in the way it runs. Buddy

[LynnJr]

Also check were the radiator hose meets the manifold top see if it has a little copper ground strap on it.If it is broke or missing the motor will flood.

[sr54x4]

Originally Posted by rs74

What about the pickup coil? When it dies have you ruled out that it may be a firing issue?

Are you referring to the ignition coil? if so, i have replaced that already. I have done cap, rotor and inginition coil so far.

Originally Posted by buddy_1

Still sounds like it's flooding out. Next time it stalls out, try holding the accelerator pedal to the floor. See if it will restart, might have to crank on it a bit. I have seen the fuel pressure regulators leak and cause them to flood. The regulator is in the throttle body, go here Rebuilding and modifying a GM TBI Fuel Injection Unit - YouTube for a video on how to replace it if needed. In the video he is modifying it to be adjustable which you shouldn't need to do but it gives you the basic procedure. Another thing is you don't have to remove the throttle body to replace the regulator it can be done on the engine. I just remembered you should also check the ECT (Engine Coolant Temp) sensor reading with a scanner, if it is bad it can tell the ECM that it's -35F degrees outside. Don't know how much that could affect it in NY but here in southeast Tx it can make a huge difference in the way it runs. Buddy

thanks, ill check these things out. thanks for the video link.

Originally Posted by LynnJr

Also check were the radiator hose meets the manifold top see if it has a little copper ground strap on it.If it is broke or missing the motor will flood.

ill check it out, thanks.