Hello all,

This the my first post here. I've read through a number of post on this forum looking for an answer (or general direction) to my problem, but haven't been able to find what I am looking for.

I have a '85 F-250 with an inline 6. The truck runs, however it doesn't seem to advance/retard the timing as it should. I believe the pictures below will illustrate why I am having a hard time fixing this. It seems as if the previous owner stripped out the emission control devices and in doing so left a mess under the hood! There are vacuum hoses that go nowhere, others that are capped off, the entire vacuum manifold is capped off. To boot, the wires coming off the distributor (which I assume electronically advance the timing) are run into a bunch of wire nuts. Other wire harnesses are seen lying around not connected to anything (or simply capped off with a wire nut.)

The truck has a plow on it, so who ever might have installed that might be the one to blame for the electrical mess.

I did the easy stuff; oil, plugs and wires, air filter...

I guess what I'm looking for is how the truck is suppose to be plumbed up. I have the vacuum diagram, but I don't know if the parts shown on it are even there anymore.

Can anyone help?

Thanks in advance, Dave

<a href="http://www.flickr.com/photos/chutneyohio/2739594535/" title="DSC_4380 by chutneyohio, on Flickr"><img src="http://farm4.static.flickr.com/3075/2739594535_a2bba675ce.jpg" width="333" height="500" alt="DSC_4380" /></a>

<a href="http://www.flickr.com/photos/chutneyohio/2740428000/" title="DSC_4378 by chutneyohio, on Flickr"><img src="http://farm4.static.flickr.com/3064/2740428000_0d52ff6a76.jpg" width="333" height="500" alt="DSC_4378" /></a>

if the pictures don't show up, you can see them and two more at:

Flickr: chutneyohio's Photostream

 

Looking at the picture, you have the computerized engine system. The distributor has no weights and no vacuum advance. The best thing you can do is buy an earlier duraspark II distributor and module, and wire that in. I would also get an earlier carb that did not require the computer also. You could get all this stuff off an early 80's or late 70's truck, or buy new at the store.

 

Man, what a mess....

Welcome to the site....Dave F is right on the money....get a Duraspark II ignition distributor and control box, non-feedback carb, and the engine wiring harness from an older truck and install them....far less headaches than trying to fix what you have there. Several parts stores web sites like Autozone, or the Chiltons manual have good vacuum diagrams.

 

Thanks for the reply!

Do you mean that there wouldn't be much benefit in re-running the vacuum lines how they are suppose to? How trivial is wiring in a new distributor?

 

Thanks Bill,

I have the vacuum diagram for it, the problem I ran into is not knowing what a the parts on the diagram are. (or if they are even on the truck anymore) For instance the white vacuum line going from the carb to the egr...where is the egr?

<a href="http://www.flickr.com/photos/chutneyohio/2742826400/" title="1985-86 4.9L Vacuum Hose Routing by chutneyohio, on Flickr"><img src="http://farm4.static.flickr.com/3167/2742826400_a3c912dd8d.jpg" width="455" height="500" alt="1985-86 4.9L Vacuum Hose Routing" /></a>

 

The vacuum layouts will be different for the new and old ignitions systems should you install the DS II system. That's why you want to get the ignition straightened out first. Then get the right vacuum diagram for that ignition. The vacuum setup for an early 80's 300 is much simpler than you have now. Reading the Haynes or Chiltpns sections will help you decode the abbreviations...also, as strange as it sounds, reading an LMC catalogue can help.

 

You could try to put it all back together, but what a headache, and an awful expense. Besides all the vacuum lines, who knows what you are missing. You are already wondering where the EGR valve is. He might have taken it off and thrown it away.

I would rather work on a modern fuel injection system than one of those things. They are supposed to get good fuel mileage when everything is working, but that must be a rare thing to happen to one of these with a lot of miles on them(working correctly that is).

Two of the most unreliable systems we see in this forum for the 80-86's are the 460 electric fuel pump systems, and the later inline six (and a few other) electronic carb systems.