Having a bit of a problem with a sticky throttle body, on a 94 E350 351W, I sprayed it down with Throttle Body cleaner and it fried out my TPS, paid a shop $165 to replace that ( I know, it was a long day that day and when I saw what it takes to change the TPS and remove the TB I would have lit the bus on fire ) ;-) . . .

Anyway the gas peddle/TB will be hard to push when taking off, once you over come it, it's fine but when you let off the gas peddle it won't return to idle, it will sit at maybe best guess 1000-1300RPM, then if you stab the gas with your foot and let off quick it will idle back down to normal, then the cycle repeats. Sometimes the trans won't down shift all the way into 1st, and I am pretty sure that's the problem.

I replaced the throttle cable and lubed the gas peddle, is it safe to spray down the TB again without removing from the bus or will it again take out my TPS, What can I do to fix this? I don't think they make affordable replacement TB's.

 

 

+1 on lubing the TB linkage, but the problem could also be a worn shaft which allows the butterflies to bind in the bores and the fix for that is to replace the throttlebody. How many miles on this thing? If it's got lots good chance the TB is worn.

 

Is there a spray cleaner for the TB bore that is recommended? The factory manual states that the TB "is a sludge resistant design and should not be cleaned".

 

 

There are a number of supposed cleaners for throttle bodies, no one brand is "better" than another really. As long as the can says it is intended for throttle bodies grab anything that suits you.

I used old tooth brushes and a small soft metal auto detailing brush mostly because it was within reach.

 

I used spray carb cleaner on my 96 a couple months ago when I replaced the TPS. I didn't lube it afterwards either. Workin fine as is, except for the stumble it's had ever since I changed the rear gear ratio to 4.10 from 3.55. Still haven't figured out the cause of the stumble.

 

Thanks guys for the advice, the bus has 197K so I doubt the TB is worn out. Turns out the shop charges an hour extra to clean the TB. Sounds like I need to bite the bullet and remove it and strip it down clean it put a Motor-Craft TPS, shop used an off brand one... Something to do when it warms up. It's only 12F today ;-(

 

It's not that hard to pull the throttle body or replace the TPS. IF the TB isn't operating smoothly I would say it probably needs lube more then it needs cleaning. I would spray the tb, where the throttle shaft goes into the body, with some WD40 or something similar. Once you spray it work the throttle. Keep opening and closing it. It's a very common problem on these, especially if they sit for any period of time. Hopefully spray it and working it a little bit will free it up. I've had to do this a few EFI 5.0L/5.8L trucks and vans.

If you want to clean it, just pull it off and clean it. You don't need to completely disassemble the throttle body to clean it. The main things to worry about is cleaning the carbon/sludge from the bores and back side of the butterflies. And pull the IAC off and clean the carbon out of it and the passages. After cleaning it I like to add a drop or two of oil anywhere the throttle shaft passes thru the main body.