what is the difference between the pre-psd, and the psd's? i'm looking to selll my 1987 f-250 with a 460 for a diesel, preferreably a powerstroke, but they are so much more expensive than a pre-psd. i dont know, any feedback would be appreciated...

 

They are both real good engines. The diesels up to 1994.5 were called "idi's" Indirect injection. From 94.5 on came the Di (direct injection) powerstroke diesels. The old ones were mechanically controlled. The powerstroke is almost completely electronically controlled. While the old idi's are good engines and make decent power if you get one thats turbo'ed. They don't really compare to the powerstroke power-wise. I'm biased and like the powerstroke, but if you find a good deal on a turbo idi you can't go wrong either. Either way, make sure the previous owners took good care of it and maybe look at some maintenance records. Look at the link below. All ya really need to know about the old body style Powerstrokes!

http://pages.prodigy.net/stevebaz/_i...az/index3.html

 

Pre-PSD is the IDI non turbocharged. They have some power, but they are slow. Both my father and grandfather owned one of each ('89 and '91) with a 5-speed. I've driven both and they are solid trucks, just not too peppy. They sold their trucks at almost 300K on the clock. My dad abused the heck out of that thing and it wouldn't break. It was wrecked twice, oil changed every 10K, basically a workhorse. My grandfather babied his and traded it for an '01. The dealer gave him too much for his trade in and called several days later when they realized his truck had that many miles. They couldn't believe how perfect condition it was in. Those motors run forever.

The PSD is turbocharged, so there's more get up and go to it which is why they are preferred. If you plan on towing in higher altitudes, you will definately want a PSD. Every diesel in our family now is a PSD (5 of them) and are all great trucks. We've had some of the OBS and almost all of us now have the Superduties. They all have run without problems and we enjoy comparing each of our trucks.

My suggestion is that you drive both and see which one you really like. Take your time to find a good deal on the truck you want.

On edit I read fox's post. Yeah the early 94's were turbo charged non psd's. I forgot to mention those.

 

Power Stroke engines are completely computer controlled.
Wires and sensors everywhere on the truck tied to the computer.
Bad sensor or broken wire can leave you stranded.
18 to 1 initial compression and about 25 pounds turbo boost.
To turn the power up you can buy chips and tuners that are expensive.

The IDI engine has been offered since 83 as a 6.9 Non turbo.
In 88 Ford changed to a 7.3 non turbo.
In 93 and 94 the IDI turbo was offered along with the 7.3 non turbo.
22 to 1 initial compression.
About 15 pounds of turbo boost.
When you turn them up you use an allen wrench. (I already had one in my tool box)
They only need one wire to run.
Most of the sensors don't work right anyway.
Over 300 thousand with only fluid changes is very common.
I like smokin Power Strokes and Dodges with mine.

 

Also worth mentioning is the 94 powerstroke is rated at 215 hp. The 94 idi turbo was rated at 190 hp. In my opinion the idi turbo number is conservitive, proably to help the powerstroke hype. My dad had the 94 idi turbo and mine the 94 psd. His would run right with mine when towing before I started mod'ing!

 

i have seen a lot more mods for the psd's though, most are computer, but wouldn't a bigger turbo almost equal it up, also, are there any power mods, for the electronics, available for the IDI's?

 

With turbo's bigger isn't always better. Bigger takes longer to spool, more exhaust to drive. Like Daves post shows 15 psi is about it on idi's. More than that and you'll be replacing head gaskets. Their is no electronic up-grades for the idi. If ya want more fuel you wrench it!