On my '91 Ff350, I've got the 7.5l paired up with the E40D tranny. After work today, I noticed it started shifting late going from first to second. Seemed okay this morning, and the issue just started today.

If I let the RPMs build up and let off the gas a little, it'll shift. Maybe a little harder than normal, but not much. If I didn't let off the gas, I don't know that it would ever shift. And it only happens coming out of first.

In case any of it's related, Full Disclosure Time:
We haven't had the truck all that long, and it was pretty filthy under the hood. The other day, I replaced the PCV valve, changed the oil, and replaced the air filter and crankcase breather air filter.

I don't know about the oil filter, but both air filters were totally clogged with oil. PCV valve wasn't clogged, but it was also just sitting next to the grommet. The hole in valve cover was basically wide open. There's might be other evidence that may have been some blow-by at some point, though it's not bad now that I can tell. I was a little worried about the possibility of blow-by, so I put some Restore in it with the new oil.

There's no check engine light, but can try to pull codes tomorrow anyway. I think I saw somewhere how to do it on OBD-I systems. For tonight though, I'm rather beat.

Any suggestions? I've done some searching, but I can't settle on anything definitive.

• Too much pressure with me putting a new PCV valve back in?
• Fuse somewhere?
• Throttle body and/or TPS since I replaced the uber-clogged filter?
• Something entirely different?

 

Brief update: Driving it again this morning, everything seemed normal for the 30 minutes I was driving. So maybe it's just happening when it's warm

 

The transmission is electronic controlled. Run the KOEO tests and stored code display.

Warm up the truck then do this: http://oldfuelinjection.packrad.net/page13.html

Or purchase a code reader such as the Equus/Innova 3145.

List the codes you get, by number and when they were displayed. We can help decipher them.

You may end up with the System Pass code 11 or 111, but it is best to start with the easy things first. Blindly replacing parts on an electronic controlled vehicle usually results in frustration and an empty wallet.

 

Tried the link, but it appears to not be working.

Shortly after my last post, I ended up putting some Lucas in it. Engine was already warm when I did, and it started shifting normally on my way home.

Unless the issue returns, I may just leave it at that for now

 

Sorry about the link..this one works better: http://web.archive.org/web/201104301...tion.com/?p=13

Good luck with the Lucas...

 

Thanks for the updated link. Still very helpful. I'm going to pull codes anyway and see if anything else is going on. I calculated that I got 8 mpg on my last fill up. I think that's about average for the 460, but anything else that might crop up that I could fix to squeeze a few more miles out of would be helpful.