I have a good old 7.3 that has me baffled. I purchased the truck last month and last week I replaced both batteries with new ones. I replaced the rubber air lines to each injector.

The Water In Fuel light is on. Will that keep the truck from starting?

I replaced the fuel filter with one that does not have the water sensor. Is this a problem?

When I plug the block heater in, sometimes the truck starts in half a second. Other times, it will just crank and crank.

This truck has been sitting for the past year + with only occasional use (once every month or two). Previous owner said all he had to do was have the block heater plugged in and it would fire right up.

I'm not depending on the truck yet, but would like to be able to soon.

I know the glow plus 100% do not work. The wires are fried. That is on my to-do list.. but I wouldn't think it would keep this truck from starting on a 70F temp day.

Is there anything else I should be looking for?

I had one of these trucks a few years ago in an F350 quad cab, but more recently I've had the next gen turbo 7.3s. This truck is my first roll-back and had to go back to the old non turbo 7.3 to get in to the game. I have a couple months before I need to use this truck.. so a check list of things to replace would be helpful towards getting me to this goal.

Any help in the right direction is appreciated. Trans is the z5 5spd if that helps.

 

The wire for the water in fuel sensor must be grounding out on something to cause the light to come on. It shouldn't effect starting at all. As long as you get your fuel from a good source and periodically drain a bit of fluid to check for water, its not a problem having a filter without the sensor.

Fixing the glow plugs should be high on your list. Even on a warm day, you might need them for the first start of the day.

You said you replaced the rubber lines to the injectors, but did you do the o-rings under the plastic caps as well?

 

You need glow plugs to start a COLD engine, and 70F is COLD, compared to combustion temperature. So yes, fix the glow plugs.

 

I had this exact problem with my truck (89 f250 7.3L). I replaced the glow plug relay from Napa (GRP109), worked like a charm. Truck fires up after only a few cranks when it's cold.

 

the glow plugs will work until the engine is over 110 degrees. so yes, you need the glow plugs at 70, or you will need to plug it in for 2 hours or more to fire it up the first start of the day.

 

Roger that. Fixing the glow plugs has now jumped towards the top of the list!

 

So after a day of working on the truck and it functioning "normally"... it stalled after running for a bit and then backing it into the parking spot I have for it. I am not able to get it to start again.

Part of today's tasks were getting the glow plugs re-wired and they are receiving 8 volts. However, the relay doesn't always close. (I don't know where it is, I can just hear when it closes) Also, the light for "Wait to start" does not always illuminate. However, the "Water in fuel" light comes on often if not every time (I don't remember exactly if it comes on every time)

Sometimes it won't crank but I do hear the solenoid on the right fender close when the key is turned to the start position.

Sometimes it will turn over, but will not start.

In the middle of trying approximately 30 times (with intervals of head scratching and looking under the hood) it chugged to life as if to start, but did not continue to run.

I'm starting to get frustrated and running out of ideas here. Can anyone fill that empty idea jar for me?

 

Relay is located on the rear of the engine below the air filter housing (need to remove this)

 

Fast cranking is essential. Check cables,connection,including earths. Check all glowplugs,connections. Check fuel supply including filter full. Check return lines for leaks(air leaking into them). Check operation of FSS. Diesels need air and fuel. These one need heat from cold on all cylinders.

 

I will check tomorrow. I'll also upload a video so you can see how fast it's cranking. Thank you for the leads.

 

I believe the starter has a dead spot. I had someone hammer on the starter and after a few blows and during contact it turned over. The Wait To Start light is no longer illuminating and the glow plug relay is not clicking. I have a new starter and glow plug relay on the way to me.

 

New starter is in. New glow plug relay is in. This is the result:



p.s. Still won't start.

 

Have fuel in the filter? bleed at injectors?

 

I have fuel in the filter (just changed it). I have not bleed at the injectors.

 

I left the block heater plugged in for a couple hours this morning and went to start the truck. Fired right up. Clearly the glow plugs are not working well correctly.

However.. now I appear to have a new issue. The truck stalls on decel. Would the injector O-rings being old/bad allow air in to make the truck stall like this? I don't know what to replace next here..