Starting and Acceleration Issues

[Marcos Beltran]

Weird things happen to vehicles that sit up for some time. Sounds like something is plugged up. Be it a return fuel line, or the cats, IDK. I have seen a dead bee get into a fuel line, and plug up the line so that it wouldnt let the gas flow at enough pressure to keep the truck running. It got hung up inside the fuel filter. So the truck would run for a little while, the the bee would get sucked up to the output line and plug up the flow. Once the truck died, the bee would fall back into the filter. Truck would start and run fine untill the bug would get sucked up again. Just 1 example of what can happen. I know you changed the fuel filter, but some times you have to think out side of the box.

I had thought about blowing out the lines. Gonna go ahead and do it this weekend. Process of elimination, one less thing to rule out. Might as well do it now that i have the bed off.

 

[stutaeng]

The problem with pushing the Schrader valve to see if there's fuel there still doesn't tell you if you have high enough pressure. You may have fuel volume, but I think you need like 55 psi (?) to actually overcome the spring pressure on the poppet valves.

I can't image why the truck would start without the pressure hose unhooked, but the other obvious source of fuel is the return line. Unless the engine would start if it was previously flooded (and probably would run only momentarily). It just happened that you killed the engine too soon before it stalled. A leaky injector and/or faulty FPR is more likely in this case.

About the EVAP. These trucks have the charcoal canister in the engine bay and they seem like they hardly had issues with fuel getting into the canister. Later on the next generation of trucks the canister got relocated next to the fuel tank underneath and it seems fuel in the canister became more of an issue on some of those. Easy enough to remove the EVAP hole and plug the purge valve. But I highly doubt enough fuel vapor from the EVAP would be enough to cause an engine to start.

 

[Marcos Beltran]

The problem with pushing the Schrader valve to see if there's fuel there still doesn't tell you if you have high enough pressure. You may have fuel volume, but I think you need like 55 psi (?) to actually overcome the spring pressure on the poppet valves.

I can't image why the truck would start without the pressure hose unhooked, but the other obvious source of fuel is the return line. Unless the engine would start if it was previously flooded (and probably would run only momentarily). It just happened that you killed the engine too soon before it stalled. A leaky injector and/or faulty FPR is more likely in this case.

About the EVAP. These trucks have the charcoal canister in the engine bay and they seem like they hardly had issues with fuel getting into the canister. Later on the next generation of trucks the canister got relocated next to the fuel tank underneath and it seems fuel in the canister became more of an issue on some of those. Easy enough to remove the EVAP hole and plug the purge valve. But I highly doubt enough fuel vapor from the EVAP would be enough to cause an engine to start.

I tried what you suggested a few days ago about seeing if the pressure drops when the ignition is on and not actually turning the truck on as that is an indicator of a leaking FPR or a injector and it seemed to dip/lower a little too much. Like a little over 10psi so that might be the issue.

 

[Schurkey]

I haven't seen anything that guarantees that this is a fuel problem.

When the truck won't start--does it have spark?

 

[Marcos Beltran]

Put scanner on it and got code PO118, engine temperature sensor 1 circuit high. So of all things thats the only code to show up or atleast the most obvious for now. I know once i get that cleared others will eventually show. So im gonna start a more in depth cleaning of the the coolant system. The sensor definitely needs replacing cause it was rusty and corroded. But the rest of the system needs a thorough once over cause with further inspection its obvious the previous owner did not maintain the cooling system. Lots of rust inside and i already put 2 containers of coolant/radiator flush. Drained it today and the fluid came out out dark as hell, literally looked like coca-cola. Never seen that before. The thermostat was rusty, gonna get replaced and the upper and lower radiator hose was full of rust and grime. Either gonna clean them out or replace them too. Radiator is gonna have to be taken out and be professionally cleaned.

 

[east302]

That code (referencing the coolant temperature sensor) would be a good place to start. If you have a scanner, see what that ECT sensor is reading. It should report ambient temperature when cold and near the thermostat setpoint when warmed up.

If it’s flaky, and reporting a strange number, it will cause the computer to mess up fuel delivery and cause hard hot starts. A workaround is to hold the gas down while cranking. This temporarily stops injector flow and is the “clear flood” mode.

Here are the diagnostics for P0118 on a 1998 350. No guarantee that it is applicable to the 4.3, but maybe it will help.

You must be registered for see images attach

You must be registered for see images attach

You must be registered for see images attach

You must be registered for see images attach

You must be registered for see images attach

 

[Schurkey]

the previous owner did not maintain the cooling system. Lots of rust inside and i already put 2 containers of coolant/radiator flush. Drained it today and the fluid came out out dark as hell, literally looked like coca-cola.

Make sure you pull the block drain plug on both sides of the engine.

Left side is likely to be a hex-head steel plug. Right side is probably the knock sensor, screwed into the block drain hole. On my vehicles, I replace the steel plugs with brass plugs, or with brass draincocks.

Remove 'em both. You may have to poke a screwdriver into the holes to puncture a layer of rust deposits that sink to the bottom of the water jacket. It's nearly impossible to get rid of the "brown/black" coolant until you drain the block--and ideally remove all the rusty accumulation at the bottom of the water jacket.

Tighten the knock sensor to the factory torque spec. when reinstalling.

If the coolant is acidic, your core plugs are likely rotted, too. Consider locating an easy-to-replace core plug, pop it out, and inspect the back side. If it's corroded, you'll need to replace them all. A kit of engine plugs should be about $15. The larger problem is getting at the ones behind the engine mounts, and behind the flywheel/flexplate. (Engine has to be removed.)

 

[Pinger]

Can you elaborate on that? Not sure i follow.

EVAP system is a system that collects (in a charcoal cannister) vapours form the fuel tank and when appropriate introduces them to the inlet manifold (there is a valve on the passenger side close to the ignition coil with an electrically controlled valve for this) where they are consumed by the engine and burned.

As per another post, probably not enough for the engine to run on alone - unless faulty? Noticeably though, when you have the fuel pipe disconnected you have changed the system from closed to open (and created a through path for air/vapours via the open pipe).

You have another avenue to pursue for now and that your problem is temperature related is plausible.

 

[Erik the Awful]

I seriously doubt it. If the EVAP sytem had that much gas in it, it should trip a check engine light.

Marcos, I think you're dealing with multiple issues. Fix the coolant temp sensor first.

Weird things happen to vehicles that sit up for some time. Sounds like something is plugged up. Be it a return fuel line, or the cats, IDK.

I think you have something gummed up from sitting. I'm not a fan of wrench-in-a-can, but run some fuel injector cleaner through it.

I have seen a dead bee get into a fuel line, and plug up the line so that it wouldnt let the gas flow at enough pressure to keep the truck running. It got hung up inside the fuel filter. So the truck would run for a little while, the the bee would get sucked up to the output line and plug up the flow. Once the truck died, the bee would fall back into the filter. Truck would start and run fine untill the bug would get sucked up again.

Storytime! I used to work for a defense contractor, performing maintenance on equipment for the Navy. We had trailer-mounted 220kw generators, and one started acting up under a load. We pulled it into the yard and started load banking it. Mind you we load bank at 10% over, so we were pulling near a quarter million watts of power from a turbocharged Detroit 6V92 running on jet fuel (high-grade kerosene). The motor ran smooth, but once we cranked the power up, it started cutting out and dropping offline (when the frequency drops the load bank cuts the connection). We fought it for a couple days, and theorized there was something in the 100+ gallon tank, but it's heavily baffled so we couldn't see it. We drilled 1/8" holes 1/4" from the bottom of the fuel pickup tube, and it helped, but it couldn't hold a full load. We finally decided to pump the tank into a fuel bowser. We dropped the suction hose into the Trilectron's tank and fired up the bowser. A couple of minutes later I was looking down into the bowser tank and saw a freakin' Kit-Kat wrapper float by! Some freakin' moron didn't have a trashcan handy and figured he'd just shove it in the fuel filler neck.

 

[Pinger]

I seriously doubt it. If the EVAP sytem had that much gas in it, it should trip a check engine light.

Unless by some freakery it's accessing liquid fuel - or some other weirdeness. The engine running with the fuel supply disconnected is as yet unexplained.

Marcos, I think you're dealing with multiple issues. Fix the coolant temp sensor first.

Full agreement on that.

I think you have something gummed up from sitting. I'm not a fan of wrench-in-a-can, but run some fuel injector cleaner through it.

IMO the FPRs can stick.
Pretty sure that was the cause of my fuelling issue last year. Running on LPG the FPR was returning all the fuel back to the tank so would have been pushed wide open. And I think it stuck there so when I tried to start it on gasoline there wasn't sufficient pressure at the nozzles. That the fuel system came good after a sizeable inlet backfire (on LPG) was it being shocked closed I think. No problem since and to avoid repetition of it I installed a pump cut-off switch.

Storytime! I used to work for a defense contractor, performing maintenance on equipment for the Navy. We had trailer-mounted 220kw generators, and one started acting up under a load. We pulled it into the yard and started load banking it. Mind you we load bank at 10% over, so we were pulling near a quarter million watts of power from a turbocharged Detroit 6V92 running on jet fuel (high-grade kerosene). The motor ran smooth, but once we cranked the power up, it started cutting out and dropping offline (when the frequency drops the load bank cuts the connection). We fought it for a couple days, and theorized there was something in the 100+ gallon tank, but it's heavily baffled so we couldn't see it. We drilled 1/8" holes 1/4" from the bottom of the fuel pickup tube, and it helped, but it couldn't hold a full load. We finally decided to pump the tank into a fuel bowser. We dropped the suction hose into the Trilectron's tank and fired up the bowser. A couple of minutes later I was looking down into the bowser tank and saw a freakin' Kit-Kat wrapper float by! Some freakin' moron didn't have a trashcan handy and figured he'd just shove it in the fuel filler neck.

I once had a frog (in bits) come through a kitchen tap despite the holes in the source strainer being smaller than frog size - but not spawn. Getting a bit off-topic here though - not helping the OP!