'89 K1500 Crank no Start

[Barbarossa38]

For context this is a yard truck that I use for plowing and moving wood. It'll never be on the road again. I just need it to move snow. I have spark and the injectors are working. When I dump fuel into the throttle body, the truck runs and idles but wont start unless I fill the bowls manually and it only runs until the fuel i've bottle fed it is gone. I'll post a link to a video of the injectors working. It looks like there should be enough fuel coming from the injectors to get it to at least try to start on it's own but I get nothing. The gas in the tank is only a couple months old and is Ethanol free so it should be fine. My oil pressure gauge has been pegged since I got the truck. Some folks are saying that sensor being bad would keep it from starting because it helps control the power to the fuel pump but it was pegged all last year while I was plowing and never kept the truck from starting. The truck has always started hard unless it's warm when it starts quickly. It'll crank for probably 5 seconds and it sputters a couple times before it finally fires up if you're starting it cold. I verfied spark with a cheap Harbor Freight inline spark tester but I do have spark on the two cylinders that I checked which were 3 and 4. Maybe a weak coil or a bad cap and Rotor?

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The sputter you hear when I start cranking is the residual fuel left over from when I filled the bowls manually. Without bottle feeding the fuel directly into the bowl I get nothing. No attempt to fire on fuel coming from the injectors. To me that says that either the injectors aren't delivering enough fuel, the fuel somehow isn't making it's way through the throttle body to the cylinders, or I'm not getting enough spark.

Things I've already changed:

8 Brand New Spark Plugs
ICM
Fuel Pump Relay
Fuel Filter (I didn't change it but it looks like it's only a few years old, definitely not original)

Where should I go from here?

 

[Erik the Awful]

You're getting fuel. You need spark. Check your distributor cap and rotor. Check to make sure your distributor shaft is turning when cranking.

 

[Schurkey]

It runs on externally-supplied fuel. Ignition system obviously works, clearly has compression and suitably-free-flowing exhaust.

It doesn't run on the existing fuel even though the injectors spray. Grab a fuel sample, find out if it burns.

 

[Schurkey]

Any progress?

 

[Barbarossa38]

Any progress?

So I did grab a fuel sample and it did not burn. So water in the fuel. I put in two bottles of ISO HEET and let it sit for a few days but it still wouldn't fire up. Still runs when I bottle feed it though. The fuel guage was reading about half a tank. I siphoned out about 5 gallons so I should have about that much left in the tank. I disconnected the fuel line from the back of the throttle body and cranked the engine a few times to get some of the fuel out of the line. I caught some of the stuff from the fuel like and that did burn but when it was done burning there was a decent amount of water left over. My question is, what is the most efficient way to get the rest of whats in the tank, out. I can't seem to get any more out siphoning and what comes out through the line at the throttle body is only in bursts because I don't want to ruin the starter. I've tried to jump the fuel pump relay but I have not been successful. There were two sets of pins that I was told to jump, the first combo almost melted my jumper wire and the second one just activated the injectors. I could hear them clicking. Should I keep attempting to jump the relay or is there a better way?

I noticed that when it's cranking, the injectors fire but when it's idling after i've filled the bowls myself they don't. I kind of assumed that was because it would be running really rich so the computer is telling the injectors not to fire. Let me know if i'm way off there.

 

[RichLo]

What do you mean when you say filling the bowls?

This is a pressurized injection system fed from the in-tank pump, not a syphon carb with reserve bowls.

When you have the fuel line off the back of the TBI, you should get a solid stream for about 3 seconds with Key-on, not cranking. If you are not covering your engine with fuel for those 3 seconds you have a fuel supply issue. Either bad fuel pump, plugged fuel pickup sock, not enough voltage to the pump or a clogged line or fuel filter.

 

[Barbarossa38]

What do you mean when you say filling the bowls?

This is a pressurized injection system fed from the in-tank pump, not a syphon carb with reserve bowls.

When you have the fuel line off the back of the TBI, you should get a solid stream for about 3 seconds with Key-on, not cranking. If you are not covering your engine with fuel for those 3 seconds you have a fuel supply issue. Either bad fuel pump, plugged fuel pickup sock, not enough voltage to the pump or a clogged line or fuel filter.

I'm spraying gas from a water bottle into the intake. How do I check to make sure the pump is getting the proper voltage?

My guess is that the water that is in the system froze and is causing an obstruction. I can check the voltage to help confirm or deny that assumption.

 

[RichLo]

The fuel pump plug is accessible from under the truck. Its right by the fuel lines, unplug it and read voltage. Shouldn't be much more than a 10% drop from battery voltage. Example 12.5v at battery -1.25v = 11.25v at pump plug minimum. That even seems low but it would still run enough to let you build fuel pressure.

Check fuel pressure at the throttle body. There is an adaptor that goes between the fuel line and the TB inlet.

And just FYI, the term 'Filling the bowls' is when you fill a carburetor through the bowl vent tubes to let it idle for a short time without any fuel pump. Not squirting gas past the throttle plates.

 

[Scooterwrench]

Take the feed line off the TB and slip a piece of hose over it so you can collect whatever the liquid is in your tank. Be careful not to lose the o-ring. Pull the connector and jump the orange and gray wires at the fuel pump relay and use the pump to pump out the tank. Once the tank is pumped dry remove the jumper wire and put the connector back on the relay. Reconnect the feed on the TB. Add a bottle of dry gas and 10 gallons of fresh fuel to the tank. It should fire up and run after a couple short bursts of the starter.

 

[Barbarossa38]

Take the feed line off the TB and slip a piece of hose over it so you can collect whatever the liquid is in your tank. Be careful not to lose the o-ring. Pull the connector and jump the orange and gray wires at the fuel pump relay and use the pump to pump out the tank. Once the tank is pumped dry remove the jumper wire and put the connector back on the relay. Reconnect the feed on the TB. Add a bottle of dry gas and 10 gallons of fresh fuel to the tank. It should fire up and run after a couple short bursts of the starter.

So this is the fuel pump relay plug. I've had a few different people tell me to jump orange to gray. There is no gray wire that I can see. Is it the black wire with the white stripe that I should be going for? i.e. 440 to 450?

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