My '90 F250 4x4 HD with the 351 has 250,000 miles on it. When I bought the truck a few years ago, it had been neglected, so I did a bunch of cooling system, drive train and brake work to it and it has been a good vehicle for the small camper that's on it. It has always run well, passes smog in CA, and has never had a CEL. (Yep, the light works).

Although I have a pretty strong background in auto mechanics, the fuel, ignition and engine management systems on this truck are a bit of a mystery to me. It seems like there are a dozen sensors with three letter acronyms that are obviously all working, but are all original 27 year old parts. I don't even know if the system is MAF or Speed Density (whatever that is).

We are planning to take this truck on an extensive, weeks long road trip this summer. My question is is there or are there any pre-emptive things I should consider cleaning, checking or changing? The only thing that has ever been done to the engine is regular oil changes, plugs, cap, rotor wires and an O2 sensor.

I don't want to cause a problem for myself- you know the saying... "if it ain't broke, just give me a minute".

 

'90 would be speed density. If it runs good leave it alone. The 27 year old sensors might still be better than the new sensor from the parts store.

The CEL light doesn't necessarily have to be on for there to be active or stored codes in the system.

 

what he said !
although some people do carry around a spare ICM for long trips, and i myself might consider a spare junkyard distributor (for the pip), a working ford sensor is worth 3 new offshore pieces of poo.

 

Yeah I hear ya.

Really kind of blows that you can't trust new parts. Doe we have to buy from Ford?

I kind of like the idea of the spare junkyard items. The only thing would be whether they work or not, and whether the truck was junked because it wouldn't start and the owner gave up on it.

Guess it would be best to pull items like that from one that was in an accident. At least that way you would know the thing was running when it met the end.

 

If you've been keeping up on things, it will be already to go, basically.

Check tires over carefully for cuts, bulges, separated tread, remove stones, and proper inflation pressure. Make sure lug bolts are torqued and check them again after a few hundred miles. Get the grease gun out and lube everything with a zerk. Make sure the cooling system/radiator is functioning at 100% and the belts are properly tensioned and hoses are good. Fresh wiper blades, even cheapies, are probably better than what's on there now.

 

I don't recommend anyone do any real work to a vehicle that isn't having any problems right before a long road trip. If it is good don't mess with it unless you can afford the down time. There are few things worse than looking your passenger/s in the eye and saying I thought I had that Fill in the Blank fixed while on the side of the road. Check your fluids, tires, etc. If you have any problems get them fixed well before the trip, and give yourself some time to drive the vehicle closer to home to make sure there aren't any problems with the repair before setting off on your trip.

On the spares thing - I used to carry spare bits and bobs but I don't really do that much anymore... maybe a few bulbs, and fuses. I don't even carry that many tools anymore. Remember to pack the tools necessary to replace whatever spares you are carrying other wise whats the point... I wouldn't carry a spare anything unless I knew it was in working order. I tend to keep parts that I take off until the new part proves itself, and even then I keep stuff around for myself or to give to some else in a tight spot on the side of the road.

On the issue of brands for parts, personally I feel OEM Ford parts are king whenever possible. That said, I have had bad parts from Ford out of the box. **** happens. I use FordParts.com mostly and have most things delivered to my door. I will take NOS Ford off of Ebay and so forth before most aftermarket parts. After Ford I trust Bosch pretty well and Borg and Warner in a pinch for widgets. If I am in a pinch and my preferred brands aren't available whatever has the best warranty wins the day...

 

I keep it in good shape. Lubed, tires, brakes, cooling system etc. are current. Even the AC works. And this isn't the first trip for this truck, I've had it in Mexico, all over the western US in all weather and temperatures. It has never failed me.

I guess the reason I'm trying to be "vigilant", is because I know all the ignition and fuel system components are original, and that if it were to quit on me, I just don't have the experience with this vehicle as I do my TDI, my Y-Block, my Subarus- all vehicles I've torn down and rebuilt and have a solid understanding of. I could get any one of those running again, I'm confident of that.

Maybe what I need to do is a little homework on the engine management for the '90 5.8 F250. This FTE website is a good resource. Since this truck s a 4x4 camper, I do tend to get the thing off the beaten track you might say....

 

I have a 91 and I pack with me a OBD1 code reader so if anything happens its pretty easy to fix. I have never been left on the side of the road with this rig but I have had the CEL come on and when I was at my destination ran the codes and fixed the problem. They are cheap to buy and mine came with a book that had the codes in it.

 

I carry a toolbox, but that's generally for fixing sleds on a trip or mountain bikes. A spare coil, multimeter, a few extra fuses, and a fuel pump relay sit in the glove box.

Ironically the one time I had a real problem way off the beaten path, was one of the few times the tool box wasn't in the truck. An animal had chewed the flexible fuel line downstream of the fuel filter while I was away backpacking for 3 nights. I had parked high in the CO mountains ~15 miles from help, unaware that this type of thing isn't unheard of. Luckily I had a Leatherman tool. I was able to use the file to cut the hard line & filter to remove the flexible section of fuel line, and then use the front diff vent hose as a temporary fuel line between the cut hard line and cut filter neck to get home. I used hose clamps from under the hood, putting zip ties in their place (coolant system operates at lower pressure than fuel). This taught me the best tool is between your ears.

 

The good news is, there aren't many things on these that will keep them from running and getting you home, and 2 working fuel pumps means the likelihood of being stranded from a failed fuel pump is minimized.

The pip, ignition module, ignition coil, and an eec are the things I carry religiously, in my regular cabs those parts fit fine behind the back seat....I've broken down but have never been stranded.

 

So the pip is in the dist., and can't be replaced in the field, so one carries a spare distributor I suppose.

I don't know where to look to find the ignition module or eec.

The coil is obvious enough.

 

Found the module. On my '90 it's mounted on the distributor.

 

I would think you would carry the spare PIP and then find an appropriately equipped shop and borrow tools and what not... but I suppose you could carry the whole assembly. I believe you have to pull the whole thing out and pull the gear which requires a press, to change the PIP. You also have to reset base timing for re installation. (Edit - It would certainly be faster to have the whole unit on hand instead of changing the sensor.)

The ignition control module is mounted directly on the distributor on early models and mounted on the driver side fender with an aluminum heat sink on later models. They are prone to heat damage, and when they begin to fail they often work fine when cold and cut out when warm, this statement could apply to PIP sensors as well. Requires thin walled socket to pull the retaining screws. (Edit - This is probably the one widget I would and should carry as well as the socket.)

EEC = Electronic Engine Control is the Ford term for the computer. Located behind the driver side kick panel. There is a retaining bolt run through the firewall from the engine bay.

 

Great information from all you guys. Thank you! I just my visit the wrecking yard to see what they have.