I have 93 yota 22 re engine. I just replaced motor and when brake is appled the engine starts to lope up and down. The motor idles fine and runs good with no brake. Any Ideas ?

 

Your warm idle is set too high.

 

And / or TPS may need adjusted, and / or you may have a vacuum leak around the booster pushrod.
But do check the idle is down around 750 and the timing is correct.

 

Bingo!!! THis is the most likely fix. Over a couple months, the idle on my truck changes a bit and I have to adjust it. I can do this at a long red light... doesnt take long at all.

 

Had the same issue when i put my new re in it.. They are right more then likely its warm idle is too high that was my problem =]

 

The booster may be leaking.
BigBlock

 

My uncle was having the exact problem on his 93 22re, the engine loped while on the brake. He ruled out all the usual fixes listed above. And the other day the truck lost power he said it was a stretch to reach 40 mph. Turned out to be the fuel pump, after he replaced that the loping stopped. Runs good with or without the brake applied.

 

And get rid of the apples

 

Leading cause it too high a warm idle, as noted above.

Why?

Read the 2nd Q&A on the page below:
- http://www.4crawler.com/4x4/TLCA_Tru...ech.04.09.html

 

One more thing to look at is the idle set screw , my 22 did the same thing and only after running for awhile I did the warm idle and booster still did it then one day I popped the hood as it was doing it and watched my idle screw slowly back itself out , put pipe thread tape on it and that worked till I replaced the screw itself turned out the o ring was worn out and did nothing to help it stay i place.

 

Thanks for everyones help. Im pretty sure the warm idle screw fixed the problem.