Well everyone this truck is making me crazy!

A little background.. 1991 7.3 I have straightened out my glow plug issues and I am positive that they are working. but for a while it has been cranking longer and longer before starting. Well aafter some thought I started to look at the fuel system and noticed that the return lines looked terrible and there was wetting arounf the plastic fittings. So I changed the fittings O-rings and all the hoses and still wont start without a shot of either.... no problem once it runs, but cannot get it to start up.

What else should I be looking at. and could someone please explain all the connections and wires going into the injection pump so I can better understand the fuel system. (or just explain the fuel system a little)

also is there supposed to be some type of vacuum breaker under the filter? I have two pipe plugs underneath on that screw on cap and nothing else.. could that be messing me up? I seem to remember seeing some kind of valve there....

Lift pump? injection pump?.... it runs great once started mind you.., but once I get out to start it cold it just won't go.

hey do glow plugs get "fouled"....I did the classic test light test and it lights up on all my plugs... now I am stumped... and this crap haynes manual doesn't tell me jack!...

Thanks,

Jeff

 

How long does the WTS light stay on. When do you attempt the start ie right after the WTS light goes out?? or are you waiting until the clicking stops.

As to the caps on the base it sounds like someone has removed the fuel/water drain and the WIF sender.

Visit......... http://www.intellidog.com/dieselmann/idi1.htm and check for the info and pic of the fuel filter.

 

No Wts Light. My Gp Controller Is Bypassed. Yeah No Wif Sender Or Drain... Any Ideas On The Schrader Valve That Has Been Pluged Up Underneath? Fuel??

 

The Schrader valve on the base is there to allow air into the filter base so fuel/water can drain........ the drain wheel when unscrewed fully will contact the Schrader valve stem. The fuel system is supposed to be a sealed system don't forget.

 

No worries about GP's fouling. Other than that I'm not much help.

 

My 91 F350 is not the greatest cold starter either even after I repaired the glow plug system, fuel air leaks and installed new 1000 CCA batteries, starter and cables. The truck runs great once it runs and does not smoke at all except the puff of while smoke after she finally fires on the 9th compression stroke during cold starting. Hot starting is no problem.

However the other day I notices a little bit of corrosion in the fuel line from the filter to the IP. Looks like the previous owner may have let some water go thru the IP and injectors at some point in time.

Evenso the truck only has 35,000 miles on it it would not suprise me if there is some corrosion in the IP or injectors that caused the injectors to slowly bleed off pressure into the cylinders during a cooldown. That would explain the puff of white smoke on cold starting as well as why none of the cylinders will fire on the first compression stroke. (i.e. unburned fuel left in the cylinders)

I am hoping that this will clear up in the next couple of month with the fuel additive I have been adding.

If not, I either live with the less than ideal cold stating or start replacing the IP and injectors.

It seems such a waste to replace an IP and injectors with such little milage on them.

 

Hmm, mine starts up very quickly cold or warm. I'm sure its doesn't get as cold here as it does in BC though - coldest I've started uppluged is about 17deg F. Mine does give a puff of white smoke on cold starts, I belive this is normal though.

 

check all fuel lines for corrosion. I had a corrosion air leak (no fuel leaking out) in the return line to the fuel tank. I found my corrosion under the frame clip that holds the lines to the frame under the left side of the truck under the drivers seat area. I had to get some hose - cut out the area of corrosion and replace with hose rated for diesel fuel. Once I did that my 93 starts right off.

 

Thanks BigRed,

My 91 did have a lot of underbody corrosion so maybe I will look at the return lines going back to the tanks aswell.

As you said, you don't have to have a fuel leak to allow air back into the return system.

 

You know My dad was having the same problem and come to find out that what he needed was a new hot pack for the glo plugs and he also needed 3 new injectors but the hot pack was the main issue. As soon as that was replaced it fired as soon as he hit the key cold or hot.

 

I got it. I wasn't holding the gps on long enough. I had heard a couple times that ten seconds is the most I should keep them on for, but I was also picking around and found that between 20 and 25 seconds may be best for my climate right now. and it fires up like a champ!... however I did replace all the fuel lines and checked and doybkle checked my gp system. I think I may need some new baterries as well cause it really kicks my battery's but to us the gps. thanks for the help everyone.

I still would like to know what all the wires connected to the ip and fuel filter are for.. if anyone knows any help would be greatly appreciated.

Thanks,

Jeff

 

the wires on the ip are for the fuel shutoff switch, cold start timing advance, and the big nut with 2 wires in the middle of it on the driver front is the tach sensor. i think the one on the fuel filter is the water in fuel sender wire, but i'm not sure on that one.

 

IP right side front is the fuel shut off solenoid.
IP right rear is the cold start timing advance solenoid.
IP left side is the cold start fast idle solenoid.

Fuel filter top of the header is the filter heater.
Fuel filter side of the filter header is the filter restriction sender.
Fuel filter bottom is the water in fuel sensor.

If you have an E4OD transmission there is also a FILP semsor for the transmission mounted on the IP.

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