Fresh New Engine - Need help trouble shooting

[jaxncurtis]

Hey guys, I just installed a fresh new 250 inline 6 engine. Started it this last week and did the first breakin and was able to get the timing set pretty much perfect. She runs GREAT!!

I never put it in gear to drive it... up until today...

I put it in gear and the truck will not go any faster than 5mph with the pedal to the floor!!

What could be the issue here? Do I have the kickdown cable two loose? Too tight? Anything else you can think of?

Im certain nothing is wrong with engine as it is running great!

Im new to installing engines so please bare with a newbie...

[kwmech]

Left the parking brake on? plugged exhaust?

[jaxncurtis]

I check parking break that is off... Rolled down drive way with no problem...

No exhaust, just headers at the moment. Was on the way to go get mufflers!!!

[SeventyOne]

Do you have fluid in the trans?

[1rippen6]

If the converted slide out and you didn't reseat it, it's possible that you jammed it into the pump. Ask me how I know, experience from my first tranny install years ago.

[litebulblsc]

What does it do when you give it more gas- does the engine speed up or stay flat?

It sounds like it is an automatic transmission. If it is a TH350, it will operate without the kick down cable. I doubt its adjustment is your issue, but you can disconect it temporarily to eliminate the possibility.

But at this point, I would advise against trying too much without verifying it is not something more serious first.

The more info and any pictures you can post could possibly help to figure out the issue.