My F-250 '88 7.3l recently started to have some issues at starting: when I crank her it takes longer for her to start up and then she doesn't run immediately on all the cylinders. It takes a few seconds before she sounds "round" again and all the cylinders are working. So is it time to change the injectors? If so which ones should I get? Or should there be more testing done to the symptoms, like bring her to a shop to check the injection system?
Thanks

 

Two things come to mind, how fast is it spinning over, and are the glow plugs working correctly.

For the starter speed, look at Tom's (tjc transport) response in this thread:
https://www.ford-trucks.com/forums/1...ning-over.html
He has a couple of videos comparing cranking speeds. You should check the condition of the battery cables, terminals/connections and how old are the batteries?

For the glow plugs, look at the glow plug sticky for the new style at the top of the forum.

If the starter/batteries/cables and glow plugs check out ok, then look towards the injection system, but check the other stuff first.

 

Sounds like air intrusion might be the culprit...

 

plug it in if it starts good after sitting with block heater (don't wait for the glows when on the block heater) if it fires good it is a glow plug problem...its prolly not air intrusion. repair one thing at a time. so you KNOW what fixed it...

 

The starter had been rebuilt not to long ago, I doubt the problem could be in the starter. Also the connections are solid. Though my batteries are a little old and on the weaker side.
And for the glow plugs the same, they have been changed recently.

 

As I mentioned, just changed the glow plugs and controller recently and fixed the problem at that time. But I will try your test anyway. Never used the block heater (Hawaii), how long should I plug it in before I try?

 

That is very well possible: Recently a return line was leaking, so i changed the o-ring, but then it was still leaking. So I got a kit to replace all the caps, fittings etc. but then the leak stopped and I didn't change it.

Now I had also fuel coming out on top of my filter head. There are 3 fittings which I dont know what they are there for (see pics)? At least on #1 and 3, it looks like some wire or air hose is missing??? For sure on #1 was fuel leaking; should I get a new filter head or can I fix this one?

I also read that it can be hard to find the point of air intrusion; someone suggested to add a electric fuel pump, so it would prime the system before cranking the engine. Now when we got this truck it only had an electric fuel pump and no more mechanical pump. But then because we live uphill the pump couldnt deliver enough fuel and the truck would starve. So I got a new mechanical pump and disconnected the electric one, and ever since I didn't have fuel starving issues. So should i maybe connect the electric pump again? Is it ok to have the mechanical and the electric one running together in line?

 

Pic 1 is the fuel heater connector. There is an oring that can leak there and would cause a hard start. Pic 2 is the schrader valve used to purge air from the filter after a change. Pic 3 is the fuel filter restriction sensor. Before starting and after sitting all night take the fuel filter off. If it is not full to the top you have air intrusion somewhere.

 

Only if the e-pump is a "through-flow" AKA "free-flow" pump, otherwise your mechanical pump will have a difficult time pulling fuel through it.

You could replace it with a free flow or just get one with the proper flow for your engine like the Carrier pump that's popular, see FAQ, and delete the mechanical completely.

Me, I'm going to go with a free flow e-primer and stick with the mechanical pump, best of both worlds IMO.

 

^^^^ Yep. On my 7.3 when I swapped it into the '85 my change fuel filter sensor (your #3) was leaking out the electrical connecter. Since my truck doesn't have this light anyway I swapped the sensor out with a small brass plug.

Like FD said, the O-rings in the fuel heater connector are replaceable, there's a real good thread in the FAQ with a write up on how to do this.

 

So that's what I did today first thing in the morning; unscreewed the fuel filter and the level was about 1.5" below the top. So air is getting in. I started the truck and checked again on the ports and the fuel heater connector is definitively leaking. So tomorrow I will get me a 1/2" brass plug and seal it. Hope this will solve the problem, if not I will take it from there.
Thanks for all the help, I learned something again.