I have a '91 F350 with a 7.3 diesel which has recently developed a minor(?) problem. When slowing down to stop or turn the engine will stop running and the engine light will come on. It starts fine and will immediately restart. It is as if the idle is too low or fuel starved when slowing. Otherwise this problem is not apparent when idleing from a cold start. The problem almost seems worse when the engine is fully warmed up and hot. ( The temperature indicator always comes up to about half way as expected)
Any suggestions as to why this occurs and what to do about it? Is this possibly a symtom of a failing injector pump?
Thanks,
Rick G.

 

I have heard of this problem and have experinced it my self but for some reason it went away. There were times I would get off the toll road and slow from 75mph to a stop and it would die even though I had full tanks and good fuel filter. This went on for about a week and then it just for no reason went away. Now and Can slam the brakes or floor it and relase and it won't die. It fixed itself. And it hassent reocured in a year or so.

Now mine Idles fine wether its cold or warm. It doesn't die anymore And would kinda like to know what caused it. Maby some one has some good input on this.

 

It was the Ford pixies! They were just messin' with ya'.

 

Sounds to me like you need to increase the idle speed a tad.

 

what is your idle speed?

 

More like the Dodge pixies messing with him because his mega cab is bigger :P I think these thangs are supoed to idle a 650ish RPM not 0 like mine. You also could have problems in the IP.

 

fuel filter maybe.

 

Lazy K, It seems to idle fine on startup but gives a problem when I deaccelerate from highway speed. How do I increase the idle speed?
Parkland, I already changed the filter, no change. I also suspected a electrical problem with a corroded battery cable & terminal. But no change after refurbishing those.
Tx.
Rick G.

 

sounds like a plugged injector(s)
dump a quart and a half of atf in your tank and run the **** out of it. if there was any thing in there it will clear it out

 

It sounds like you may have a governor problem inside your injector pump; the weights stick in their "high idle" position either from wear or other things. You may try the atf trick, some Diesel Kleen or i like to use Marvel Mystery Oil in the fuel

 

Even if it is not the basic problem, increasing the idle speed may make it more pleasant to drive. Look for the throttle stop screw on the linkage at the injector pump. You should be able to screw that out a bit. It could also be that you need the pump timing advanced slightly as it sounds like it idles OK when the cold start advance is on. However try setting the idle speed with the engine at operating temp. and see how that goes.

 

Remove fuel filter and reinstall after filling with Diesel Kleen, or Tranny fluid. Then pour 2-4 courts tranny fluid in tank and drive it, see if it gets better.

 

This sounds like some sound advice; DO NOT put any kind of additive in the filter, that would be MUCH too concentrated. Adding some ATF in the tank, and doing some major accelerating, decelerating, will work the systems and hopefully wake the ***** up! Even #2 should clean her out a little, if you drive it "right"

 

No offence and I could be wrong but, I never heard that being a problem with these older diesels. Thats what I have done at work on the old IDIs. (usually atf but I have used DKleen and some other additive) IS it a problem on the newer Powerstroke trucks with them High dollar high pressure HEUI injectors?

I would think as long as it has some sort of lubrication in the cleaner, it should work on ours. I have heard many people doing this on just this IDI forum alone all the time I don't hear of too many IP failuers. I have filled my filter up several times with it. First I used tranny fluid then I went to dieselkleen. I have had this truck for over a year 1/2 and 30,000 miles with no troubles and I don't know when the IP was changed last. Every time we change Filters at work on IDIs, We fill them with ATF or DK on our IDIs then spin them on, And we have alot of 7.3 IDIs here and very very rarly do we have an IP failer or even a failure of any kind on these engines. I can only think of 1-2 IPs failling since I have been here for over 2 1/2 years I have worked here with probably at least 30 7.3 IDI trucks (not sure on actual count since around 340 some trucks all look the same) I Sure could be wrong and maby were hurting the IPs. I Would like more input on exacty what parts we are haveing a negitive effect on by it being too concetrated.
As of Now on my personal truck, I don't use any additvies, It runs great so I feel theres no point in it.

 

Using some ATF etc concentrated is great, its just that when you got problems, remember the viscosity is thicker than #2 and can contribute to a no-start condition.

In other words, I wouldnt use it unless you can guarantee the truck will be running at least long enough to burn it out.